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Brown root rot disease (BRRD) is a highly destructive tree disease. Early diagnosis of BRRD has been challenging because the first symptoms and signs are often observed after extensive tissue colonization. Existing molecular detection methods, all based on the internal transcribed spacer (ITS) region, were developed without testing against global Phellinus noxius isolates, other wood-decay fungi, or host plant tissues. This study aimed to develop SYBR Green real-time quantitative PCR (qPCR) assays for P. noxius . The primer pair Pn_ITS_F/Pn_ITS_R targets the ITS, and the primer pair Pn_NLR_F/Pn_NLR_R targets a P. noxius -unique group of homologous genes identified through a comparative genomics analysis. The homologous genes belong to the nucleotide-binding-oligomerization-domain-like receptor (NLR) superfamily. The new primer pairs and a previous primer pair G1F/G1R were optimized for qPCR conditions and tested for specificity using 61 global P. noxius isolates, 5 other Phellinus species, and 22 non- Phellinus wood-decay fungal species. Although all three primer pairs could detect as little as 100 fg (approximately 2.99 copies) of P. noxius genomic DNA, G1F/G1R had the highest specificity and Pn_NLR_F/Pn_NLR_R had the highest efficiency. To avoid false positives, the cutoff quantification cycle values were determined as 34 for G1F/G1R, 29 for Pn_ITS_F/Pn_ITS_R, and 32 for Pn_NLR_F/Pn_NLR_R. We further validated these qPCR assays using Ficus benjamina seedlings artificially inoculated with P. noxius , six tree species naturally infected by P. noxius , rhizosphere soil, and bulk soil. The newly developed qPCR assays provide sensitive detection and quantification of P. noxius , which is useful for long-term monitoring of BRRD status., Competing Interests: The author(s) declare no conflict of interest.

In September 2023, thirty declining 30-year-old avocado (Persea americana) trees ('Hass' grafted on 'Zutano' seedlings) were detected in a 1.5-ha orchard in the island of Crete (Chania region). Crown symptoms encompassed wilting and leaf chlorosis, advancing to defoliation and extensive dieback. Tap and feeder roots decayed and brown discoloration of root tissues was evident on heavily infected trees. The disease was severe and widespread, resulting in a 5% mortality rate among 300 trees. The pathogen was isolated with a modified soil baiting technique (Ferguson and Jeffers, 1999). Surface disinfected avocado fruits were immersed in water containing soil samples. Following a period of 2 to 8 days, tissue fragments from the resulting necrotic lesions on the fruit surface were transferred on ΡΑRP medium and subsequently incubated at 20°C (Ferguson and Jeffers, 1999). Three isolates (AV2, AV12 and AV11a) were obtained by transferring single hyphal tips to new Petri dishes containing V8 juice agar. They were grown at 20˚C and used for identification after 10 days. Isolates formed coralloid colonies with abundant clustered spherical hyphal swellings and terminal or intercalary (ratio 1:5) thick-walled chlamydospores measuring 20 to 36 μm (avg 29±0.8 μm) with characteristic thick walls (avg 1.2±0.2 μm). Sporangia, produced in non-sterile soil-extract water, were ovoid to obpyriform, persistent, non-papillate, 32 to 81 μm (avg 56±4.8 μm) long and 20 to 42 μm (avg 31±3.2 μm) wide (n=100). Isolates were heterothallic as they did not produce oospores in single cultures. Based on the morphological traits the isolates were identified as Phytophthora cinnamomi (Erwin and Ribeiro 1996). The internal transcribe spacer region (ITS) including ITS1, 5.8S rDNA region, and ITS2 as well as the cytochrome c oxidase subunit I (coxI) gene of the three representative isolates wereamplified with ITS1/ITS4 and FM83/FM84 primers, respectively (White et al. 1990; Martin and Tooley 2003), and sequenced (GenBank acc. PP506613 to PP506615 and PQ063867 to PQ063869, respectively). BLAST search revealed almost 100% identity with the sequences of P. cinnamomi ex-isotype isolate (KC478663 and KU899315 respectively). Pathogenicity tests using isolate AV2 were conducted following the soil infestation method (Jung et al. 1996) using six-year-old avocado 'Zutano' seedlings. Six non-inoculated plants treated with vermiculite-multivitamin juice mixture were used as controls. Plants (1 m tall) were grown in pots under greenhouse conditions and watered regularly. Six weeks post inoculation, all inoculated trees showed chlorosis, wilting and root rot, while control plants remained symptomless. Symptoms were similar to those observed in the field and the pathogen was re-isolated and molecularly identified as previously described. This study presents the first documented occurrence of P. cinnamomi, widely regarded as the most destructive avocado pathogen globally, on avocado crops in Greece (Rodger et al. 2019). Additionally, this marks the first recorded presence of this pathogen on the island of Crete, regardless of the host species. The accurate identification of Phytophthora species associated with avocado root rot is essential for implementing an effective disease management strategy, particularly in the selection of appropriate disease-resistant rootstocks.

Beech leaf disease (BLD), an emerging threat to American beech ( Fagus grandifolia ) in the northern United States and Canada, was recently confirmed to be caused by the nematode Litylenchus crenatae subsp . mccannii (hereafter L. crenatae ). Consequently, there is a need for a rapid, sensitive, and accurate method for detecting L. crenatae for both diagnostic as well as control purposes. This research developed a new set of DNA primers that specifically amplify L. crenatae and allow for accurate detection of the nematode in plant tissue. These primers have also been used in quantitative PCR (qPCR) to determine relative differences in gene copy number between samples. This primer set provides an improved, effective tool for monitoring and detecting L. crenatae in temperate tree leaf tissue which is necessary to understand the spread of this emerging forest pest and to develop management strategies., Competing Interests: The author(s) declare no conflict of interest.

Brown root rot disease (BRRD), caused by Phellinus noxius , is an important tree disease in tropical and subtropical areas. To improve chemical control of BRRD and deter emergence of fungicide resistance in P . noxius , this study investigated control efficacies and systemic activities of fungicides with different modes of action. Fourteen fungicides with 11 different modes of action were tested for inhibitory effects in vitro on 39 P. noxius isolates from Taiwan, Hong Kong, Malaysia, Australia, and Pacific Islands. Cyproconazole, epoxiconazole, and tebuconazole (Fungicide Resistance Action Committee [FRAC] 3, target-site G1) inhibited colony growth of P. noxius by 99.9 to 100% at 10 ppm and 97.7 to 99.8% at 1 ppm. The other effective fungicide was cyprodinil + fludioxonil (FRAC 9 + 12, target-site D1 + E2), which showed growth inhibition of 96.9% at 10 ppm and 88.6% at 1 ppm. Acropetal translocation of six selected fungicides was evaluated in bishop wood ( Bischofia javanica ) seedlings by immersion of the root tips in each fungicide at 100 ppm, followed by liquid or gas chromatography tandem mass spectrometry analyses of consecutive segments of root, stem, and leaf tissues at 7 and 21 days posttreatment. Bidirectional translocation of the fungicides was also evaluated by stem injection of fungicide stock solutions. Cyproconazole and tebuconazole were the most readily absorbed by roots and efficiently transported acropetally. Greenhouse experiments suggested that cyproconazole, tebuconazole, and epoxiconazole have a slightly higher potential for controlling BRRD than mepronil, prochloraz, and cyprodinil + fludioxonil. Because all tested fungicides lacked basipetal translocation, soil drenching should be considered instead of trunk injection for their use in BRRD control., Competing Interests: The author(s) declare no conflict of interest.

Crassula capitella Thunb. is a succulent used ornamentally in gardens and landscapes. In August 2019, severe powdery mildew infection was observed on C. capitella in a plant nursery, 1000m2 in area, in Xining (36°42'44.39" N, 101°44'50.50″E, alt. 2330 m), China. Approximately 35% of the leaves on a plant were symptomatic, and 80% of the plants were affected. The disease seriously reduced the ornamental value. A voucher specimen was deposited in the Herbarium of Plant Pathology at Qinghai University under accession no. QHU2019150. The pathogen formed superficial mycelia on leaves and stems producing conspicuous white colonies followed by necrosis of the leaf tissues and defoliation. Mycelia were amphigenous, white, effuse or in patches, persistent with lobed appressoria. The pathogen produced conidia singly on 2- to 3-celled conidiophores occurring on the ectophytic hyphae. Conidia were subcylindrical, measured 22 to 41 × 10 to 16 (n = 50) µm, and were produced singly on the tip of conidiophores. Conidiophores were erect and up to 110 µm long, foot-cells straight, cylindrical and 22 to 53 × 8 to 10 (n = 50) µm, followed by one to three shorter cells. Chasmothecia were not found. The fungus was identified as Erysiphe sedi based on morphology (Braun and Cook 2012). To confirm the identification, the ITS region was amplified. The ITS5/P3 and PM5/ITS4 primers were used to amplify the ITS region by nested PCR, and the cloned fragments were sequenced (Takamatsu and Kano 2001). The aligned ITS region sequences were deposited in GenBank (accession no. MT178769). A BLAST search analysis of the two sequences revealed 99.84% identity with E. sedi infecting Sedum aizoon in Russia (LC010045). A phylogenetic tree was constructed in MEGA6 with 15 ITS sequences using the neighbor-joining method with the Kimura 2-parameter substitution model. The sequence retrieved from powdery mildew on Crassula capitella in China clustered together with the sequences obtained from E. sedi on Sedum spp. with nearly 100 % concordance, placing it in the Erysiphe aquilegiae complex as defined by Takamatsu et al. (2015) and recently critically discussed by Shin et al. (2019). This complex comprises numerous Erysiphe spp. insufficiently resolved, especially when based only on ITS data. However, for the time being we follow Götz et al. (2019) and recognize E. sedi as a species of its own and identify the Chinese collection on Crassula capitella as E. sedi because of the morphological agreement and concordant ITS data. Pathogenicity tests were completed by gently pressing infected leaves onto five healthy leaves of C. capitella, Inoculated and non-inoculated plants were maintained separately in different rooms of a greenhouse at 22 to 25°C. Inoculated plants developed signs and symptoms after 12 days, whereas control plants remained symptomless. The morphology of the fungus on inoculated leaves was identical to that originally observed on diseased plants. To our knowledge, this is the first report of powdery mildew caused by Erysiphe sedi on C. capitella in China and worldwide, although E. sedi is reported to infect many Crassulaceous or Crassulaceae hosts (Cho et al. 2012, Götz et al. 2019).

Widespread decline and mortality of white oaks (Quercus alba) occurred in Missouri Ozark forests between 2011 and 2017. Symptoms included rapid crown death with bronzing of leaves, retention of dead leaves, crown dieback and thinning, and loss of large limbs within one year of death. Decline and mortality were associated with hillside drainages and fit descriptions of European oak forests predisposed to decline by pathogenic Phytophthora species. A survey was performed at two locations in 2014 and 2015 to assess the distribution of dead and declining white oaks, and the occurrence and distribution of Phytophthora species. Multiple Phytophthora species were detected, including P. cinnamomi, P. cactorum, P. europaea, and P. pini. P. cinnamomi was the most common and widely distributed species among plots at both locations. The detection of P. cinnamomi at the base of white oaks was not associated with poor crown vigor. However, more quantitative survey techniques are necessary to clearly evaluate this relationship. P. cinnamomi kills fine roots of white and red oaks in North America and has been associated with the decline of white oaks in the United States (Ohio) and other countries. Further studies are needed to determine the importance of P. cinnamomi in oak decline within the Ozark highlands.

Phytophthora pluvialis is associated with early defoliation and shoot dieback in Douglas-fir in Oregon and New Zealand. In 2013, P. pluvialis was described from mixed tanoak-Douglas-fir forests in the Pacific Northwest and concurrently recognized as the main causal agent of red needle cast (RNC) in New Zealand radiata pine plantations. Little is known about its infection cycle and impact on host physiology. P. pluvialis studies in Douglas-fir are challenging due to the ubiquitous presence of the endophyte Phaeocryptopus gaeumannii, which produces similar symptoms and premature defoliation with persistent needle wetness, known as Swiss needle cast (SNC). Nonetheless, our study showed P. pluvialis infection in the presence of SNC. Exclusive expression of P. pluvialis is difficult to achieve as both diseases are promoted by high humidity. Here we established a 'dry leaf' strategy to suppress SNC when inoculating Douglas-fir needles for RNC studies. Sheltering plants along with drip irrigation to avoid needle wetness during the P. gaeumannii sporulation period suppressed its development in the new season flush. The diminished endophyte inoculum enabled bias-reduced studies of P. pluvialis impacts on Douglas-fir without the confounding effects of stomatal blockage and premature defoliation caused by P. gaeumannii.

Puccinia psidii (Myrtle rust) is an emerging pathogen that has a wide host range in the Myrtaceae family; it continues to show an increase in geographic range and is considered to be a significant threat to Myrtaceae plants worldwide. In this study, we describe the development and validation of three novel real-time polymerase reaction (qPCR) assays using ribosomal DNA and β-tubulin gene sequences to detect P. psidii. All qPCR assays were able to detect P. psidii DNA extracted from urediniospores and from infected plants, including asymptomatic leaf tissues. Depending on the gene target, qPCR was able to detect down to 0.011 pg of P. psidii DNA. The most optimum qPCR assay was shown to be highly specific, repeatable, and reproducible following testing using different qPCR reagents and real-time PCR platforms in different laboratories. In addition, a duplex qPCR assay was developed to allow coamplification of the cytochrome oxidase gene from host plants for use as an internal PCR control. The most optimum qPCR assay proved to be faster and more sensitive than the previously published nested PCR assay and will be particularly useful for high-throughput testing and to detect P. psidii at the early stages of infection, before the development of sporulating rust pustules.

During a pinewood nematode survey in 2011, a dead pitch pine (Pinus rigida) was found in Daejeon city, Korea. Samples were taken from several regions of the trunk and nematodes were extracted from the wood samples by a modified Baermann funnel method (1). Recovered nematodes were then cultured on Botrytis cinerea grown in potato dextrose agar (PDA) medium. Males and females (n = 10) were examined under an inverted light microscope. Morphologically, these nematodes were identified as Bursaphelenchus yongensis sharing the characters of the genus Bursaphelenchus including a large median bulb, offset cephalic region, a well-developed stylet with small basal knobs, female with vulva at 70% of body length, and males with terminal bursa. Females of B. yongensis were similar to B. muconatus and B. fraudulentus by presence of tail mucron, but they were differentiated by a smaller vulval flap. Males had spicules with small cucullus, pointed rostrum, and with strongly dorsally bent condylus. The identity of the nematode was confirmed through molecular diagnosis. DNA was extracted from each of 10 nematodes using commercial DNeasy kits (Qiagen, Valencia, CA) and the ITS regions were amplified with a primer set by PCR (Bio Rad, US/PTC-0220) (3,5). Amplified ITS DNA was cloned and sequenced, and the sequence data was deposited to GenBank (Accession No. KJ857070). The ITS sequence of Korean isolate (KJ857070) showed 99% similarity to that from Chinese isolate in GenBank (AM180513). ITS-RFLP patterns using five different restriction enzymes, RsaI, HaeIII, MspI, HinfI, and AluI, matched 100% with those previously reported for B. yongensis (2,4). Host pathogenicity tests were conducted from June to August on saplings of five native and introduced conifer species found in Korea (Abies sp., Larix leptolepsis, P. koraiensis, P. strobus, and P. thunbergii). All saplings were 5 to 6 years old and 15 saplings were inoculated for each species. B. yongensis was cultures on B. cinerea for 10 days at 25°C and the inoculum concentration was calibrated at 5,000 nematodes/50 μl sterile water. Nematodes were artificially inoculated by making a 1-cm-long incision into the stem using a sterile razor blade. B. yongensis was pathogenic on L. leptolepsis, causing wilt and death in all inoculated saplings; however, the nematode had no effect on P. thunbergii, P. koraiensis, Abies sp., or P. strobus. To our knowledge, this is the first report of B. yongensis in Korea. This nematode is a potential threat to L. leptolepsis; however, the role of B. yongensis in the mortality of P. rigida is uncertain at this time. References: (1) S. M. Ayoub. Plant Nematology in Agricultural Training Aid. Department of Food and Agriculture, Division of Plant Industry, Sacramento, CA, 1977. (2) W. Burgermeister et al. Nematology 11:649, 2009. (3) V. R. Ferris et al. Fund. Appl. Nematol. 16:177, 1993. (4) J. Gu et al. Russian J. Nematol. 14:91, 2006. (5) T. C. Vrain. J. Nematol. 25:361, 1993.

The Republic of Korea (South Korea) is the second largest chestnut producer in the world. Major cultivars planted in Korea, including cv. Daebo, Hyogo57, and Okkwang, are hybrids of Japanese chestnut (Castanea crenata) and Chinese chestnut (C. mollissima). Because of high perishability, most chestnuts harvested in September and October are preserved in cold rooms (0°C) for marketing. During a survey of postharvest diseases in April to August 2013, chestnut rots were continuously observed in cold rooms located in Buyeo County, Korea. Preliminary studies revealed that the most common agent of rot appeared to be a species of Mucor. When cut open, infected chestnuts showed partial interior discoloration varying from chalky white to dark brown. About 3 to 10% of chestnuts showed symptoms. Hyogo57 seemed to be the most susceptible variety with higher infection rates, up to 30% in some piles. Isolation was done by placing infected tissues on potato dextrose agar. A representative isolate was deposited in the Korean Agricultural Culture Collection (Accession No. KACC47727). Sporangiophores were mostly erect, branched sympodially, and hyaline. Sporangia were globose, pale yellow at first, then grayish brown at maturity. Columellae were obovoid to globose, subhyaline to pale brown, and usually with truncate base and collars. Sporangiospores were globose to irregular, and 4 to 10 μm in diameter. Chlamydospores were cylindrical to globose with oil drops. The fungus was identified as Mucor racemosus f. sphaerosporus (Hagem) Schipper based on the morphological characteristics and growth at low temperature (3). To conduct molecular analyses, genomic DNA was extracted with DNeasy Plant Mini Kits (Qiagen Inc., Valencia, CA). The primers ITS1/ITS4 and NL1/LR3 were used to amplify the internal transcribed spacer (ITS) region of rDNA and the D1/D2 region of the large subunit (4). The resulting 595-bp ITS sequences and 678 bp D1/D2 sequences were deposited in GenBank (Accession Nos. KJ769665 and KF769666). BLAST searches revealed that both the ITS sequences and D1/D2 sequences showed more than 99% similarity with those of M. racemosus f. sphaerosporus, respectively (JN939201 and AJ878775). To perform a pathogenicity test, a suspension of sporangiospores (1 × 10 5 spores/ml) was sprayed over 10 chestnuts cv. Hyogo57 wounded with a sewing needle and kept in plastic containers (0°C, 100% RH). Another 10 chestnuts wounded with a sewing needle and treated with sterile water served as controls. After 5 days, typical rots appeared on the inoculated chestnuts, whereas no symptoms were observed on controls. Koch's postulates were fulfilled with the re-isolation of M. racemosus from inoculated chestnuts. The pathogenicity test was carried out twice with similar results. M. hiemalis and M. mucedo have been recorded on chestnuts as postharvest pathogens in Switzerland (2) and Chile (1). To our knowledge, this is first report of postharvest rot of chestnut caused by M. racemosus f. sphaerosporus worldwide as well as in Korea. Further studies are necessary for control measures during cold storage of fresh chestnuts. References: (1) D. F. Farr and A. Y. Rossman. Fungal Databases. Syst. Mycol. Microbiol. Lab., online publication, ARS, USDA, Retrieved May 23, 2014. (2) M. Jermini et al. J. Sci. Food Agric. 86:877, 2006. (3) M. A. A. Schipper. Stud. Mycol. 12:1, 1976. (4) G. Walther et al. Persoonia 30:11, 2013.

Actinidia arguta (Siebold & Zucc.) Planch. ex Miq., known as hardy kiwi, is a perennial vine native to Japan, Korea, northern China, and Russian Siberia. It produces a small fruit resembling the kiwifruit. The fruits, referred to as hardy kiwifruit, are edible and often sweeter than kiwifruit. Picking of wild hardy kiwifruits in autumn is a popular ecotourism activity in Korea. In 2000, a powdery mildew disease on the abaxial surface of hardy kiwi leaves was found in Korea. Additional findings of the powdery mildew between 2000 and 2013 showed that the disease of hardy kiwi commonly occurs in Korea. The infected leaves were frequently distorted when young, then becoming prematurely chlorotic and defoliated. Chasmothecia were abundantly formed by September. Voucher specimens (n = 21) were deposited in the Korea University Herbarium (KUS). Mycelia were hypophyllous, thinly effuse, initially forming patches, finally covering the whole abaxial leaf surface. Hyphal appressoria were hook-shaped or often branched, and single or opposite in pairs. Conidiophores were erect, cylindrical, 160 to 300 × 5 to 7.5 μm with straight foot-cells (65 to 115 μm long), basal septum elevated up to 15 μm, and produced conidia singly. Conidia were obpyriform to clavate, papillate at the apex, 55 to 75 × 20 to 32 μm, and devoid of fibrosin bodies. Germ tubes were produced at the terminal and lateral positions of conidia. Chasmothecia were blackish brown, depressed globose, and 190 to 250 μm in diameter. Appendages arising around the equatorial zone of chasmothecia were 9 to 15 in number, acicular with a bulbose base, 1 to 1.3 times as long as the chasmothecial diameter, hyaline throughout, and aseptate. Penicillate cells crowded on the upper part of the chasmothecia were ampulliform, numerous, 50 to 87.8 μm long, and 12.5 to 17.5 μm wide. Asci were 13 to 20 in a chasmothecium, olivaceous brown, 60 to 90 × 22.5 to 40 μm, and short stalked. Ascospores were 2 in an ascus, ellipsoid-ovoid, pale olivaceous, and 32.5 to 40 × 16.5 to 20 μm. On the basis of the morphological characteristics, this fungus was identified as Phyllactinia actinidiae (Jacz.) Bunkina (1). To confirm the identification, the complete internal transcribed spacer (ITS) regions of rDNA of three specimens (KUS-F23673, F26240, and F26308) were amplified using primers ITS5/P3 and sequenced (4). The resulting sequences were deposited in GenBank (Accession Nos. KJ703014, KJ703015, and KJ703016). GenBank BLAST search with the three isolates showed >99% similarity with the results for P. actinidiae on hardy kiwi from Japan (AB080489, AB080500, and AB080508). Actinidia-Phyllactinia associations were recorded in China, Japan, Taiwan, Korea, Russia, and Turkey (2,3). However, P. actinidiae on A. arguta was known only from Japan (3). To our knowledge, this is the first record of P. actinidiae on hardy kiwi in Korea. There has been no finding of powdery mildews on commercial varieties of golden kiwi (A. chinensis) and fuzzy kiwi (A. deliciosa) in Korea. Common occurrence of Phyllactinia powdery mildew on hardy kiwi in Korea can be a potential threat to the commercial kiwi industry. References: (1) U. Braun and R. T. A. Cook. Taxonomic Manual of the Erysiphales (Powdery Mildews), CBS Biodiversity Series No.11. CBS, Utrecht, 2012. (2) I. Erper et al. Scand. J. Forest Res. 27:432, 2012. (3) D. F. Farr and A. Y. Rossman. Fungal Databases. Syst. Mycol. Microbiol. Lab., Online publication. ARS, USDA, March 10, 2014. (4) S. Takamatsu et al. Mycol. Res. 113:117, 2009.

Dictamnus dasycarpus Turcz, known as densefruit pittany, is a perennial herbal plant belonging to the Rutaceae. In Oriental medicine, this plant is used for treatment of various ailments (4). Since the white and purple striped flowers and glossy leaves are of aesthetic value, the plant is popular in gardens throughout Korea. In July 2012, a leaf spot was observed on hundreds of D. dasycarpus with nearly 100% incidence in a garden in Gapyeong County, Korea. Lesions on leaves reaching up to 20 mm in diameter were circular to irregular, brown to dark brown, then becoming zonate with age, and finally fading to grayish brown in the center with a reddish brown margin. The disease caused premature defoliation and reduced plant vigor as well as aesthetic value. In June 2014, the same symptoms were found on D. dasycarpus in a nursery in Jinju City, Korea. Representative samples were deposited in the Korea University Herbarium (KUS). Pycnidia on lesions were epiphyllous, immersed or semi-immersed in host tissue, light brown to olive brown, and 90 to 210 μm in diameter. Ostioles were 15 to 30 μm wide and surrounded by a ring of darker cells. Conidia were hyaline, smooth, ellipsoidal to nearly reniform, straight to mildly curved, aseptate or rarely medianly 1-septate with age, 5.5 to 9.6 × 1.8 to 3.6 μm, and contained small oil drops. These characteristics were consistent with the previous descriptions of Phoma dictamnicola Boerema, Gruyter & Noordel. (1,2). A monoconidial isolate was cultured on potato dextrose agar plates and deposited in the Korea Agricultural Culture Collection (Accession No. KACC46948). Morphological identification of the fungus was confirmed by molecular data. Genomic DNA was extracted using a DNeasy Plant Mini Kit (Qiagen Inc., Valencia, CA). The internal transcribed spacer (ITS) region of rDNA was amplified using the ITS1/ITS4 primers and sequenced. The resulting sequence of 505 bp was deposited in GenBank (Accession No. KM047023). A BLAST search showed that the ITS sequence shared >99% similarity with that of P. dictamnicola (GU237877). For the pathogenicity tests, inoculum was prepared by harvesting conidia from 30-day-old cultures of KACC46948 and a conidial suspension (2 × 10 6 conidia/ml) was sprayed onto leaves of five healthy seedlings. Five seedlings were sprayed with sterile distilled water, serving as controls. The plants were covered with transparent plastic bags for 48 h in a 25°C glasshouse with a 12-h photoperiod. After 10 days, typical leaf spot symptoms started to develop on the leaves of the inoculated plants. The fungus, P. dictamnicola, was re-isolated from those lesions, confirming Koch's postulates. No symptoms were observed on control plants. Previously, Phoma leaf spot on Dictamnus spp. has been reported in the Netherlands and North America (3) and recently in China (1). To our knowledge, this is the first report of leaf spot on D. dasycarpus caused by P. dictamnicola in Korea. Our observations suggest that low humidity with good ventilation as well as removal of infected leaves and plant debris might be main strategies for preventing this disease. References: (1) Q. Bai et al. Plant Dis. 95:771, 2011. (2) G. H. Boerema et al. Phoma Identification Manual: Differentiation of Specific and Infra-Specific Taxa in Culture. CABI Publishing. Wallingford, UK, 2004. (3) D. F. Farr and A. Y. Rossman. Fungal Databases. Syst. Mycol. Microbiol. Lab., Online publication, USDA ARS, Retrieved June 19, 2014. (4) J. L. Yang et al. Planta Med. 77:271, 2011.

Catalpa bignonioides Walter, known as southern catalpa or Indian bean tree, is native to the southeastern United States and are planted as shade trees throughout the world. In August 2009, typical powdery mildew symptoms on several leaves of the plants below 5% disease incidence were observed in a public garden of Hongcheon County of Korea. In 2011 to 2013, hundreds of southern catalpa trees were found heavily damaged by a powdery mildew with 90 to 100% disease incidence in a park of Incheon City of Korea, about 140 km apart from Hongcheon County. Symptoms appeared as circular to irregular white patches, which subsequently showed abundant mycelial growth on both sides of leaves and herbaceous stems. Severe infections caused poor growth and premature loss of leaves, resulting in reduced aesthetic value. Voucher specimens (n = 6) were deposited in the Korea University Herbarium (KUS). Appressoria on the mycelium were well-developed, lobed, and solitary or in opposite pairs. Conidiophores composed of 3 to 4 cells were 70 to 100 × 7.5 to 10 μm, and produced conidia singly. Foot-cells of conidiophores were flexuous or nearly straight, and 20 to 40 μm long. Conidia were oblong to oblong-elliptical, measured 30 to 42 × 13 to 20 μm (n = 30) with a length/width ratio of 1.6 to 2.5, devoid of distinct fibrosin bodies, and showed angular/rectangular wrinkling of outer walls. Primary conidia were apically rounded, basally subtruncate, and generally smaller than the secondary conidia. Germ tubes were produced on the end of conidia. Chasmothecia were not observed. These structures are typical of the Pseudoidium anamorph of the genus Erysiphe. The specific measurements and characteristics were compatible with those of E. elevata (Burrill) U. Braun & S. Takam. (1,2). To confirm the identification, the complete internal transcribed spacer (ITS) region of rDNA from KUS-F27676 was amplified with primers ITS5 and P3 (4) and sequenced directly. The resulting 675-bp sequence was deposited in GenBank (Accession No. KF840721). A GenBank BLAST search of the ITS sequence showed >99% similarity with isolates of E. elevata on C. bignonioides (Accession Nos. AY587012 to AY587014). Pathogenicity was confirmed through inoculation by gently dusting conidia onto leaves of five healthy southern catalpa seedlings. Five non-inoculated plants served as controls. Inoculated and non-inoculated plants were maintained in a greenhouse at 24 to 28°C in isolation. Inoculated plants developed symptoms after 6 days, whereas the control plants remained symptomless. The fungus present on the inoculated plants was identical morphologically to that originally observed on diseased plants. E.elevata is a North American powdery mildew on Catalpa species which was recently introduced into Europe (1,2,3). To our knowledge, this is the first report of powdery mildew caused by E. elevata on C. bignonioides in Asia as well as in Korea. The disease would be a serious threat to the widespread ornamental plantings of C. bignonioides in Korea. References: (1) N. Ale-Agha et al. Mycol. Prog. 3:291, 2004. (2) U. Braun and R. T. A. Cook. Taxonomic Manual of the Erysiphales (Powdery Mildews), CBS Biodiversity Series No.11. CBS, Utrecht, 2012. (3) D. F. Farr and A. Y. Rossman. Fungal Databases, Syst. Mycol. Microbiol. Lab., Online publication. ARS, USDA. Retrieved November 4, 2013. (4) S. Takamatsu et al. Mycol. Res. 113:117, 2009.

Quercus glauca Thunb. (syn. Cyclobalanopsis glauca (Thunb.) Oerst.), known as ring-cupped oak or Japanese blue oak, is a dominant tree species commonly found in evergreen forests in East Asia (2). In May 2012, hundreds of Q. glauca were found heavily affected by a powdery mildew in several locations of Jeju Islands, Korea. Symptoms on overwintered leaves appeared as circular to irregular blackish violet to dark brown felt-like growths with numerous chasmothecia on abaxial leaf surfaces. New infections on current-year leaves started in early summer and were characterized by typical white patches with abundant sporulation on abaxial leaf surfaces. In early autumn, with formation of special aerial hyphae and without further sporulation, the patches turned light brown to brown. Formation of chasmothecia was noticed from late autumn. The adaxial leaf surface was free of powdery mildew growths and exhibited yellowing and discoloration. Voucher specimens were deposited in the Korea University Herbarium (KUS). Special aerial hyphae were falcate to curved, aseptate, at first hyaline, later deep brown to purplish brown, thick-walled, and 80 to 140 × 6 to 15 μm. Conidiophores were 175 to 245 × 10 to 12 μm, and produced 2 to 4 immature conidia in chains with a sinuate outline. Foot-cells of conidiophores were cylindrical and 80 to 120 μm long. Conidia were lemon- to barrel-shaped, 26 to 35 × 17 to 24 μm with a length/width ratio of 1.2 to 1.6, and devoid of fibrosin bodies. Primary conidia were apically conical and basally subtruncate. Germ tubes produced in the lateral to perihilar position of conidia were long and slender (3 μm wide). Chasmothecia were scattered or gregarious, partly embedded with special aerial hyphae, dark brown, spherical, 55 to 70 μm in diameter, and contained a single ascus. Chasmothecial peridia consisted of two layers. Exoperidia (outer layer) were composed of dark brown, polygonal cells 10 to 20 μm wide. Endoperidia (inner layer) consisted of hyaline, polygonal cells 10 to 15 μm wide. Appendages were basally attached, mycelioid, rare or few, and pale brown to rusty brown. Asci were short stalked, 55 to 72 × 35 to 46 μm, had a terminal oculus 10 to 20 μm wide, and contained 8 ascospores. Ascospores were oblong-elliptical, 22 to 27 × 10 to 12.5 μm, subhyaline, and contained 1 or 2 oil drops. The specific measurements and characteristics (especially falcate aerial hyphae) were consistent with those of Cystotheca wrightii Berk. & M.A. Curtis (1). Fungal DNA was extracted by the Chelex method. The internal transcribed spacer (ITS) region of rDNA of KUS-F27309 was amplified with primers ITS5/P3 and sequenced directly (4). The resulting 589-bp sequence was deposited in GenBank (Accession No. KF735066). A BLAST search in GenBank showed that the Korean isolate had 100% homology with C. wrightii on Q. glauca from Japan (AB000932). Powdery mildews of Q. glauca associated with C. wrightii have been known in Japan, Taiwan, and China (1,3), but not in Korea. Finding of C. wrightii on Q. glauca could pose a potential threat to other evergreen oak species in southern part of Korea. References: (1) U. Braun and R. T. A. Cook. Taxonomic Manual of the Erysiphales (Powdery Mildews), CBS Biodiversity Series No. 11, CBS, Utrecht, Netherlands, 2012. (2) X. Y. Chen et al. Acta Bot. Sin. 39:149, 1997. (3) D. F. Farr and A. Y. Rossman. Fungal Databases. Syst. Mycol. Microbiol. Lab., Online publication, ARS, USDA, retrieved 21 October, 2013. (4) S. Takamatsu et al. Mycol. Res. 113:117, 2009.

Beach vitex, Vitex rotundifolia L. fil., is a perennial that grows in temperate and tropical areas of the Pacific. In areas where it has been introduced outside of its native range, beach vitex has proven to be an invasive species. This plant dominates dune ecosystems leading to a reduction in the prevalence of native species (1). In October 2010, previously unknown leaf spots were observed on the beach vitex growing on sand dunes in Incheon City of Korea. The same symptoms were repeated in 2011 and 2012. In September 2012, the same leaf spots were found on the beach vitex in Samcheok and Gyeongju in Korea. The symptoms usually started as small, dark brown to purplish leaf spots with more or less concentric rings, eventually causing leaf blights or yellowing with 50% or more defoliation by the end of September. Representative samples (n = 6) were deposited in the Korea University Herbarium (KUS). Conidiophores of the fungus observed microscopically on the leaf spots were erect, brown to dark brown, single or occasionally in clusters, 80 to 500 × 5 to 9 μm, and mostly arose on the abaxial surface of symptomatic leaves. Conidia were borne singly or in short chains of 2 to 4, ranging from cylindrical to broadest at the base and tapering apically, straight to slightly curved, pale olivaceous brown, 1 to 12 pseudoseptate, 50 to 250 × 8 to 18 μm, each with a conspicuous thickened hilum. On potato dextrose agar (PDA), single-spore cultures of two isolates were identified as Corynespora cassiicola (Berk. & M.A. Curtis) C.T. Wei on the basis of morphological and cultural characteristics (3). Two monoconidial isolates were preserved at the Korean Agricultural Culture Collection (Accession Nos. KACC45712 and KACC46953). Isolate KACC45712 was used for molecular works and pathogenicity test. Genomic DNA was extracted using the DNeasy Plant Mini DNA Extraction Kit (Qiagen Inc., Valencia, CA). The complete internal transcribed spacer (ITS) region of rDNA was amplified with the primers ITS1/ITS4 and sequenced. The resulting sequence of 520 bp was deposited in GenBank (Accession No. KC987359). A BLAST search in GenBank revealed that the sequence showed 100% identity with those of C. cassiicola (e.g., JQ801302). To conduct a pathogenicity test, a conidial suspension (ca. 2 × 10 4 conidia/ml) was prepared by harvesting conidia from 2-week-old cultures, and the suspension was sprayed onto the leaves of three healthy seedlings. Inoculated plants were kept in humid chambers for 48 h in a glasshouse. After 5 days, typical leaf spot symptoms started to develop on the leaves of all three inoculated plants. C. cassiicola was reisolated from the lesions, confirming Koch's postulates. Control plants treated with sterile water remained symptomless. C. cassiicola is cosmopolitan with a very wide host range (2,4). To our knowledge, C. cassiicola has not been reported on Vitex spp. anywhere in the world. According to field observations in Korea, Corynespora leaf spot was most severe in August and September, especially following a prolonged period of moist weather. C. cassiicola may be a potential biocontrol agent for this highly invasive species. References: (1) M. C. Cousins et al. Invasive Plant Sci. Manag. 3:340, 2010. (2) L. J. Dixon et al. Phytopathology 99:1015, 2009. (3) M. B. Ellis. Dematiaceous Hyphomycetes. Commonw. Mycol. Inst.: Kew, UK, 1971. (4) D. F. Farr and A. Y. Rossman. Fungal Databases. Syst. Mycol. Microbiol. Lab., Online publication, ARS, USDA, Retrieved April 30, 2013.

Farfugium japonicum (L.) Kitam (common name: Leopard plant) is known as a medical herb and belongs to family Asteraceae (1). In June 2012, a leaf spot disease was observed on the leaf surface of F. japonicum at a forest research plot Jinju, Gyeongnam province, Korea. More than 95% of F. japonicum plants were infected and leaf spot symptom appeared in the regions under our investigation. Light brownish symptoms initially developed and the spot size gradually increased and turned dark brown with an irregular shape as the disease progressed (spot size 1 to 10 mm in diameter). At the late stage of disease, spots became hollow and completely dehydrated. The infected leaves were easily crumbled, possibly due to dryness. To isolate the causal agent, the infected leaves were surface disinfected and pieces of leaves were placed on water agar (WA). Nine isolates were isolated from 10 pieces of the infected leaves. Fungi mycelia from the WA were transferred on potato dextrose agar (PDA) and incubated at 28°C for 7 days. The colonies were purple navy to black and conidia spores developed on the media. The morphological characteristics of spores were multi-septate, dark brown, pyriform, and 6.7 to 12.8 × 22.2 to 38.4 μm. The spores had 1 to 4 transverse and 0 to 3 longitudinal septa. The morphological characteristics of the isolates showed considerably similar to well-known Alternaria tenuissima (2). The leaf spot disease caused by A. cinerariae of F. japonicum was reported from Japan (3). Spores of A. cinerariae are golden brown to brown with 3 to 9 transverse and 0 to 6 longitudinal septa and are 87.5 × 28.7 μm (avg.) (3). To verify pathogenicity of the isolate, the pure cultured fungi on the PDA medium was taken (4 mm in diameter) and placed on healthy leaves of Leopard plant. The artificially inoculated leaves were placed on wet filter paper in Petri dishes and incubated at 25°C and 80% humidity. At 7 days after inoculation, similar disease symptoms developed on 8 out of 10 infected Leopard plant leaves. The pathogen was reisolated from artificially infected leaves. To identify in molecular biology level, genomic DNA was extracted and the ITS-rDNA region was amplified using universal primers ITS1 and ITS4. The amplified PCR product was purified and sequenced (528 bp) with ITS1 and ITS4 primers for both directions and then deposited in GenBank (Accession No. KC415611.1). The BLAST search showed that it matched previously reported A. tenuissima with 100% identity. To the best of our knowledge, this is the first report of Leopard plant leaf spot disease in Korea. References: (1) E. Y. Kim et al. J. Ethnopharmacol. 146:40, 2013. (2) E. G. Simmons. Page 1 in: Alternaria Biology, Plant Diseases and Metabolites. J. Chelchowski and A. Visconti, eds. Elsevier, Amsterdam, 1992. (3) T. Sakoda et al. Res. Bull. Pl. Prot. Japan 46:73, 2010.

Hibiscus mutabilis L., known as cotton rose, is a deciduous shrub native to China. Horticultural varieties of the species are widely planted throughout the world (4). In September 2012, typical powdery mildew symptoms on the cotton rose were observed in a public garden of Jeju City, Korea. Powdery mildew colonies were circular to irregular white patches on both sides of the leaves and also on young stems and sepals. As the disease progressed, white mycelial growth covered the entire shoot portion, causing leaf distortion. In the middle of November, numerous chasmothecia were formed on the lesions. Voucher specimens (n = 4) were deposited in the Korea University Herbarium (KUS). Hyphal appressoria were only swollen part of hyphae or occasionally nipple-shaped. Conidiophores were 140 to 275 × 10 to 11.5 μm and produced 2 to 8 immature conidia in chains with a crenate outline. Foot-cells of conidiophores were straight, 30 to 65 μm long, and cylindric. Conidia were hyaline, ellipsoid-ovoid, and measured 27 to 42 × 17.5 to 21 μm with a length/width ratio of 1.5 to 2.4, and had distinct fibrosin bodies. Chasmothecia were amphigenous, cauligenous, 85 to 110 μm in diameter, and contained one ascus each. Peridium cells of chasmothecia were irregularly polygonal, large, and 15 to 38 μm wide. Appendages were mycelioid, 1- to 6-septate, brown at the base, and becoming paler. Asci were sessile, oval to broadly fusiform, with terminal oculus of 15 to 20 μm wide. Ascospores numbered eight per ascus were ellipsoidal, 19 to 25 × 14 to 16 μm. The morphological characteristics were consistent with previous records of P. xanthii (Castagne) U. Braun & Shishkoff (1). To confirm the identification, the complete internal transcribed spacer (ITS) region of rDNA from isolate KUS-F27134 was amplified with the primers ITS5 and P3 and sequenced (3). The resulting sequence of 477 bp was deposited in GenBank (Accession No. KC460208). The Korean isolate showed >99% similarity with dozens of sequences of P. xanthii ex cucurbitaceous hosts (e.g., JQ912061, JQ409565, HM070403, etc.) as well as Podosphaera sp. ex H. mutabilis from Japan (AB040308). Pathogenicity was confirmed through inoculation tests by gently pressing diseased leaves onto young leaves of three asymptomatic, potted 2-year-old seedlings. Three non-inoculated seedlings were used as controls. Plants were maintained in a greenhouse at 24 to 30°C. Inoculated leaves developed symptoms after 7 days, whereas the control plants remained symptomless. The fungus present on the inoculated leaves was morphologically identical to that observed on the original diseased leaves, fulfilling Koch's postulates. Powdery mildew infections of H. mutabilis associated with P. xanthii (including P. fuliginea in broad sense) have been known in China, Japan, and Taiwan (1,2). To our knowledge, this is the first report of powdery mildew caused by P. xanthii on H. mutabilis in Korea. Since Jeju, the southmost island of Korea, is the only habitat of cotton rose in Korea and is the northmost natural habitat in Asia, powdery mildew is a new threat to the health of wild populations of cotton rose. References: (1) U. Braun and R. T. A. Cook. Taxonomic Manual of the Erysiphales (Powdery Mildews), CBS Biodiversity Series No.11. CBS, Utrecht, 2012. (2) D. F. Farr and A. Y. Rossman. Fungal Databases. Syst. Mycol. Microbiol. Lab., Online publication, ARS, USDA, retrieved January 18, 2013. (3) S. Takamatsu et al. Mycol. Res. 113:117, 2009. (4) D. A. Wise. J. Hered. 64:285, 1973.

Oriental white oak, Quercus aliena Blume, is native to East Asia including Korea. It is one of the major deciduous tree species in natural forests in Korea. In May 2012, several hundred trees were found to be heavily damaged by a previously unknown leaf disease in a forest near Songjiho Lake in Goseong County of central Korea. Leaf symptoms began as small, water-soaked, pale greenish to grayish lesions, which enlarged to follow the veins or midribs and to be bounded by them, often killing part of the leaf. Leaf distortion and blight resulted in the later stage of disease development. A number of grayish brown to nearly black acervuli were formed on the lesions, especially on the midribs and veins. Acervuli were mostly hypophyllous, intraepidermal, erumpent, circular to ellipsoid in outline, cushion-like, and 70 to 220 μm in diameter. Conidia (n = 30) were elliptical to fusiform-elliptical, occasionally obclavate, aguttulate or guttulate, hyaline, aseptate, and 7.5 to 20 × 5 to 7.5 μm (mean 14.6 × 6.1 μm). These morphological characteristics of the fungus were consistent with the description of conidial state of Apiognomonia errabunda (Roberge ex Desm.) Höhn. (3,4). Voucher specimens were deposited in the Korea University Herbarium (KUS). An isolate obtained from KUS-F26690 was deposited in the Korean Agricultural Culture Collection (Accession No. KACC46842). Fungal DNA was extracted with DNeasy Plant Mini DNA Extraction Kits (Qiagen Inc., Valencia, CA). The complete internal transcribed spacer (ITS) region of rDNA was amplified with the primers ITS1/ITS4 and sequenced. The resulting 549-bp sequence was deposited in GenBank (KC426947). This showed >99% similarity with sequences of A. errabunda (AJ888475 to 888477). For pathogenicity test, inoculum was prepared by harvesting conidia from 4-week-old cultures on potato dextrose agar. A conidial suspension (1 × 10 6 conidia/ml) was sprayed onto young leaves of three potted seedlings. Three seedlings treated with sterile distilled water served as controls. Plants were covered with plastic bags to maintain 100% relative humidity for 24 h and then kept in a greenhouse (20 to 26°C and 60 to 80% RH). After 26 days, typical leaf spot symptoms, identical to the ones observed in the field, developed on the inoculated leaves. No symptoms were observed on controls. A. errabunda was reisolated from the lesions of inoculated plants, fulfilling Koch's postulates. Oak anthracnose associated with A. errabunda (including A. quercina) has been recorded in Europe and North America (1,4). Oak anthracnose of evergreen Quercus glauca Thunb. (syn. Cyclobalanopsis glauca (Thunb.) Oerst.) associated with A. supraseptata in Japan is not related to this disease (2). To our knowledge, this is the first report of oak anthracnose of Q. aliena globally and also the first finding of A. errabunda in Asia as well as in Korea. This pathogen is known as one of the major forest pathogens in oak stand in Europe and North America (3). Pending further studies, including a risk assessment, A. errabunda may be considered as a potentially new and serious threat in native and planted ranges of Q. aliena in Korea. References: (1) D. F. Farr and A. Y. Rossman. Fungal Databases. Syst. Mycol. Microbiol. Lab., Online publication, ARS, USDA, retrieved February 18, 2013. (2) S. Kaneko and T. Kobayashi. Trans. Mycol. Soc. Japan 25:11, 1984. (3) A. Ragazzi et al. Phytopathol. Mediterr. 46:295, 2007. (4) M. V. Sogonov et al. Mycol. Res. 111:693, 2007.

Smoothlip cymbidium (Cymbidium kanran Makino) is one of the national endangered species in Korea and in situ and ex situ conservation measures have been implemented for its threatened habitat and population. Jeju Island in Korea is one of few places where wild populations of the plant remain. In 2012, leaf blotch and blight occurred on leaves of smoothlip cymbidium in Jeju Island throughout the growing season. Affected plants were collected in May and October to determine the causal agent. Leaves had multiple brownish lesions that often developed from the leaf tip or leaf margin, eventually coalescing together and proceeding toward the base. In the lesions, fungal fruiting bodies formed concentric rings and exuded salmon-colored spore masses when put in moist chambers for 1 to 2 days. Colletotrichum gloeosporioides was consistently isolated from the spore masses or the margins of fresh lesions. When cultured on potato dextrose agar (PDA), colonies were olive to gray on the upper side and dark gray to black on the reverse side. On affected leaves, mature acervuli were dark brown to black, waxy, subepidermal, circular to ellipsoid, and 142 to 255 μm in diameter. Setae on the acervuli were dark brown, acicular, and 67 to 103 μm long. Conidia were hyaline, cylindrical with both ends rounded, and 13.7 to 19.2 × 4.0 to 6.1 μm. Hyphopodia were lobed and 7.6 to 13.7 × 5.7 to 11.6 μm (43 to 157 μm 2 in area). These morphological characteristics were consistent with descriptions of C. gloeosporioides (1,3). The identities of two representative isolates were confirmed by sequencing the internal transcribed spacer (ITS) regions and the large subunit (LSU) rDNA (GenBank Accession Nos. KC408373, KC408374, and KC408375). BLAST analysis of the sequences from each isolate against the GenBank database found 99% similarities to more than 30 accessions of C. gloeosporioides (e.g., AY266392, EU552111). Pathogenicity was tested with one isolate on four leaves obtained from four plants of asymptomatic smoothlip cymbidium. Two places on the epidermis of each leaf were gently pinpricked using a sterile dissecting needle. One disk (0.6 cm diameter) of either PDA containing the fungus or sterile water agar was placed on one of the two places on each leaf. Laboratory film and aluminum foil held the disks in place. Inoculated leaves were kept in a moist chamber for 24 hr. After 1 week, buff-colored lesions with young acervuli were found on all fungus inoculation sites but no lesions occurred with control inoculations. C. gloeosporioides was recovered from all inoculations, but not from the controls. To our knowledge, this is the first report of anthracnose caused by C. gloeosporioides on smoothlip cymbidium in Korea. The same fungus has been previously reported to cause anthracnose of other orchid plants in the genera Aspidistra, Cymbidium, and Dendrobium in Korea (2). This pathogen can pose a threat to smoothlip cymbidium. References: (1) M. Du et al. Mycologia 97: 641, 2005. (2) The Korean Society of Plant Pathology. List of Plant Diseases in Korea, 5th ed. The Korean Society of Plant Pathology, Suwon, Korea, 2009. (3) B. C. Sutton. Pages 1-26 in: Colletotrichum: Biology, Pathology, and Control. J. A. Bailey and M. J. Jeger, eds. CAB International, Wallingford, U.K., 1992.

Melia azedarach L., called chinaberry, is native to Southeast Asia and Australia. The trees are commonly planted as ornamentals in the southern part of Korea. In October 2010, a leaf spot disease was observed on trees for the first time in Wando, Korea. Further surveys conducted from 2010 to 2012 showed that the disease occurs on trees in Jeju, Seogwipo, and Tongyeong cities as well as Wando county with nearly 100% incidence. Leaf spots were circular to semicircular, later becoming angular, small, pale brown in the center with a dark brown margin, and later becoming milky white. Leaf spots sometimes coalesced to blight the entire leaf and were capable of rapidly defoliating whole trees in late September. Fruiting was amphigenous, but mostly hypogenous. Stromata were substomatal, globular, dark brown, and 25 to 70 μm in diameter. Conidiophores were densely fasciculate, pale olivaceous to pale brown, substraight to mildly curved, not geniculate, 10 to 30 μm long, 2.5 to 4.5 μm wide, and aseptate or uniseptate. Conidia were pale olivaceous, generally darker than conidiophores, cylindric to obclavate, substraight in shorter ones, curved to mildly sinuous in longer ones, obconically truncate at the base, obtuse at the apex, 2- to 14-septate, 16 to 120 × 3 to 5 μm, guttulate, and had inconspicuous hila. Morphological characteristics of the fungus were consistent with the previous descriptions of Pseudocercospora subsessilis (Syd. & P. Syd.) Deighton (2). Voucher specimens (n = 6) were deposited in the Korea University Herbarium (KUS). An isolate from KUS-F25395 was deposited in the Korean Agricultural Culture Collection (KACC45688). The complete internal transcribed spacer (ITS) region of rDNA was amplified with the primers ITS1/ITS4 (3) and sequenced. The resulting sequence of 517 bp was deposited in GenBank (Accession No. JX993904). A BLAST search in GenBank revealed that the sequence shows >99% similarity (1 bp substitution) with a sequence of P. subsessilis ex M. azedarach from Cuba (GU269815). For pathogenicity tests, hyphal suspensions were prepared by grinding 3-week-old colonies grown on potato dextrose agar with distilled water using a mortar and pestle. Five 3-year-old chinaberry trees were inoculated with hyphal suspensions using a fine haired paint brush. Three healthy trees of the same age, serving as controls, were sprayed with sterile water. The plants were covered with plastic bags to maintain 100% relative humidity for 24 h and then transferred to a greenhouse. Typical symptoms of necrotic spots that appeared on the inoculated leaves 10 days after inoculation were identical to the ones observed in the field. P. subsessilis was reisolated from symptomatic leaf tissues, confirming Koch's postulates. No symptoms were observed on control plants. The disease has been reported in several Asian countries as well as in Cuba and the United States (1). To our knowledge, this is the first report of leaf spot on chinaberry caused by P. subsessilis in Korea. The observed high incidence and severity suggest that this disease can be a limiting factor in utilizing this tree species as ornamentals in public areas. References: (1) D. F. Farr and A. Y. Rossman. Fungal Databases. Syst. Mycol. Microbiol. Lab., Online publication, ARS, USDA, Retrieved October 22, 2012. (2) Y. L. Guo and W. H. Hsieh. The genus Pseudocercospora in China. International Academic Publishers, Beijing, China, 1995. (3) T. J. White et al. PCR Protocols. Academic Press, San Diego, CA, 1990.

Rose of Sharon, Hibiscus syriacus L., is a flowering shrub in the family Malvaceae planted as the national flower of South Korea. In September 2012, previously unknown leaf spots with premature defoliation were observed on dozens of Rose of Sharon plants growing in the shaded area in a park of Dongducheon, Korea. The same symptoms were found on Rose of Sharon in several localities of Korea in 2012. The symptoms usually started as small, dark brown to grayish leaf spots, eventually causing leaf yellowing with significant premature defoliation. The diseased leaves retained for a while green color at the margin of the spots. Representative samples (n = 5) were deposited in the Korea University Herbarium (KUS). Conidiophores of the fungus observed microscopically on the leaf spots were erect, brown to dark brown, single or in clusters, amphigenous but mostly hypophyllous, and measured 80 to 400 × 5 to 10 μm. Conidia were borne singly or in short chains, ranging from cylindrical to broadest at the base and tapering apically, straight to slightly curved, pale olivaceous brown, 2 to 16 pseudoseptate, 50 to 260 × 9 to 20 μm, each with a conspicuous thickened hilum. On potato dextrose agar, single-spore cultures of two isolates were identified as Corynespora cassiicola (Berk. & M.A. Curtis) C.T. Wei on the basis of morphological and cultural characteristics (1,2). Two monoconidial isolates were preserved at the Korean Agricultural Culture Collection (KACC46956 and KACC46957). Genomic DNA was extracted using the DNeasy Plant Mini DNA Extraction Kit (Qiagen Inc., Valencia, CA). The complete internal transcribed spacer (ITS) region of rDNA was amplified with the primers ITS1/ITS4 and sequenced. The resulting sequences of 520 bp were deposited in GenBank (Accession Nos. KC193256, KC193257). A BLAST search in GenBank revealed that the sequences showed 100% identity with those of numerous C. cassiicola isolates from diverse substrates. To conduct a pathogenicity test, a conidial suspension (ca. 2 × 10 4 conidia/ml) was prepared in sterile water by harvesting conidia from 2-week-old cultures of KACC46956, and the suspension was sprayed onto the leaves of three healthy 2-year-old plants. Inoculated plants were kept in humid chambers for the first 48 h and thereafter placed in the glasshouse. After 10 days, typical leaf spot symptoms developed on the leaves of all three inoculated plants. C. cassiicola was reisolated from the lesions, confirming Koch's postulates. Control plants treated with sterile water remained symptomless. C. cassiicola is cosmopolitan with a very wide host range (1,2). Though Corynespora hibisci Goto was recorded to be associated with brown spot disease of H. syriacus in Japan (4), there is no previous record of C. cassiicola on H. syriacus (3). To our knowledge, this is the first report of Corynespora leaf spot on Rose of Sharon in Korea. According to our field observations in Korea, this disease was found in August and September, following a prolonged period of moist weather. Severe infection resulted in leaf yellowing and premature defoliation, reducing tree vigor and detracting the beauty of green leaves. References: (1) L. J. Dixon et al. Phytopathology 99:1015, 2009. (2) M. B. Ellis. Dematiaceous Hyphomycetes. Commonw. Mycol. Inst., Kew, UK, 1971. (3) D. F. Farr and A. Y. Rossman. Fungal Databases. Syst. Mycol. Microbiol. Lab., Online publication, ARS, USDA, Retrieved November 22, 2012. (4) K. Goto. Ann. Phytopathol. Soc. Japan 12:14, 1942.

Roots of laurel oak (Quercus laurifolia Michx.), member of the family Fagaceae, were found to be heavily galled by the pecan root-knot nematode, Meloidogyne partityla, in two separate home gardens between 2010 and 2012, in Alachua Co., FL. Distinct round galls were observed on secondary and tertiary roots. Internally, root-knot nematode females were clearly visible when the roots were thinly sliced and egg masses were seen protruding from the root surfaces. The nematode species identification was performed using morphology of the male stylet, selected characters of the second-stage juveniles (J2), female perineal patterns, and esterase (EST) and malate dehydrogenase (Mdh) isozyme phenotypes. Morphology of perineal patterns of females, body, stylet, and tail length of the J2 and males all matched those of the original description of M. partityla (2). A swollen deeply grooved rectum was observed in the J2. The male stylet had a blunt tip with a prominent thickening at the junction between the cone and shaft. The stylet knobs of males and females were bipartite, each incised by a deep medium longitudinal groove (2). The isozyme phenotypes (EST = Mp3; Mdh = N1a) were consistent with those previously reported for M. partityla from Florida (1). Mitochondrial DNA (mtDNA) (3) and ribosomal internal transcriber spacer (ITS) DNA (4) of females were amplified to further confirm the nematode species identification. The mtDNA amplification using the C2F3/1108 primer set (3) and the ITS amplification using a recently available M. partityla specific primer set (4) produced fragments of approximately 530 bp and 550 bp, respectively. These were consistent with those already reported for this nematode species. This first report of a plant host for the pecan root-knot nematode outside of the family Juglandaceae indicates that the nematode may have migrated from Quercus species to pecan trees during the period when orchards were being established in Florida. To our knowledge, this is the first report of the pecan root-knot nematode infecting laurel oak. References: (1) J. A. Brito et al. Nematology 10:757, 2008. (2) Kleynhans, K. P. N. Phytophylatica 18:103, 1986. (3) T. O. Powers et al., J. Nematol. 37:226, 2005. (4) R. A. Stamler. M. S. thesis, New Mexico State University, Las Cruces, 2009.

Mexican petunia (Ruellia brittoniana) is an herbaceous flowering perennial with strikingly colored flowers, widely cultivated commercially as a potted plant and a popular garden plant. In July of 2010, root and stem rot that caused death was observed on Mexican petunia at the flower nursery of the Council of Agriculture & Chiayi County in Taiwan. Plants had rotted and girdled stem bases. Necrotic areas were covered with fans of white mycelium as well as abundant spherical sclerotia. A fungus was isolated from infected tissue and sclerotia, and maintained on potato dextrose agar (PDA) plates incubated at 25°C without light. Colonies were white, cottony, often forming fans; pure cultures were prepared by transferring hyphal tips to PDA. Sclerotia formed after 10 days, initially white becoming dark brown with age, and 0.5 to 0.6 mm in diameter. To confirm identity of the causal fungus, the complete internal transcribed spacer (ITS) rDNA region of the causal fungus was amplified using the primers ITS4 and ITS5 (2) and sequenced. The resulting sequence of 687 bp was uploaded in NCBI. The sequence was 98% similar to sequences of Athelia rolfsii (Sclerotium rolfsii) in NCBI (Accession No. JN543691.1). Koch's postulates were performed using two inoculation techniques. The soil near the base of healthy Mexican petunia plants (four plants per pot) were exposed to recently matured sclerotia (10 sclerotia per plant) developed from pure fungal cultures or 10-mm-diameter agar plugs of mycelium (one plug per plant). Noninoculated plants, in a separate pot, were used as a control. All plants were incubated in a growth chamber at 28 to 33°C. Disease symptoms occurred on all inoculated plants by 5 to 7 days and included yellowing of leaves, basal stem rot, and wilt. Ten days after inoculation, inoculated plants were dead whereas control plants remained healthy. The pathogenicity test was repeated twice with similar results and S. rolfsii was reisolated from infected plants in each test. The pathogen has been reported to cause substantial loss of Mexican petunia in Louisiana (1). The disease is becoming more common in Taiwan and could cause losses in Mexican petunia production. To our knowledge, this is the first report of disease on Mexican petunia caused by S. rolfsii in Taiwan. References: (1) G. E. Holcomb. Plant Dis. 88:770, 2004. (2) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. M. A. Innis et al., eds. Academic Press, 1990.

Euphorbia punicea (Euphorbiaceae), commonly known as Jamaican poinsettia, is an evergreen shrub with dark green leaves and flashy red bracts. Bracts are sharply contrasted by rosettes of dark green leaves and can be observed in early summer, spring, fall, and winter. This shrub, native to Jamaica, is suitable in southern climates both in the landscape and as a seasonal patio container plant. Outdoors, the plants can reach as high as 5 meters. In January of 2012, E. punicea plants growing in an ornamental nursery in Dade Co., Florida, were observed with stunted growth and yellowing leaves. Root systems of affected plants were collected and sent to the Florida Department of Agriculture and Consumer Services, Nematology Laboratory, Gainesville, FL. Root systems showing symptoms of root-knot nematode infections were heavily galled and had already started rotting. Galls were observed in the primary, secondary, and tertiary roots. Species identification was initially performed using morphology and morphometrics. The morphology of the perineal patterns and measurements of selected characters of the second-stage juveniles fit those of the original description for M. enterolobii (3). The nematode species identification was confirmed using PCR to amplify mtDNA with the C2F3/1108 primer set (1) and a species-specific SCAR primer set, MK7-F/MK7-R (2). The PCR products were approximately 700 bp for mtDNA and approximately 520 bp for the SCAR, which were identical to those previously reported for M. enterolobii (1, 2). Sanitation practices should be implemented to avoid the spread of this nematode species within and between ornamental nurseries. Planting material should be produced in media free of this pathogen to avoid its introduction into uninfested nurseries and landscape areas. M. enterolobii has a wide host range, including cover and vegetable crops, fruit trees, herbs, and ornamental and weed plants. To our knowledge, this is the first report worldwide of E. punicea as a host of M. enterolobii. References: (1) T. O. Powers et al. J. Nematol. 37:226, 2005. (2) M. S. Tigano et al. Plant Pathol. 59:1054, 2010. (3) B. Yang and J. D. Eisenback. J. Nematol. 15:381, 1983.

Widely cultivated commercially, Iresine herbstii Hook is a potted herbaceous plant popular for its foliage, which varies from a dark red to brownish maroon. In the summer of 2010, a sudden wilt of I. herbstii plants was observed at a recreational farm in Taipei City in northern Taiwan. The initial symptoms were water-soaked lesions that became soft and then rotted. Necrotic areas on the stems were covered with fans of white mycelium as well as abundant spherical, brown sclerotia. A fungus was isolated from both infected tissue and sclerotia and maintained on potato dextrose agar (PDA) plates incubated at 25°C without light. Colonies were white and cottony, often forming mycelial fans. Pure cultures were prepared by transferring single hyphal tips to PDA. Sclerotia formed after 7 days. Sclerotia were initially white becoming dark brown with age and were 0.8 to 1 mm in diameter at maturity. These are typical features of Sclerotium rolfsii. Koch's postulates were performed by inoculating five healthy, potted I. herbstii plants with 10 fresh sclerotia placed on the soil surface around the base of each plant. In a second test, five healthy potted plants were inoculated with a single 10-mm-diameter mycelial agar plug placed at the stem base of each plant. Five noninoculated plants served as controls. All plants were incubated in a growth chamber at 25 to 35°C. Basal stem rot and wilt developed within 4 days on plants inoculated with sclerotia or mycelial plugs. All plants were dead by 7 days after inoculation whereas the controls remained healthy. The fungus was reisolated from the symptomatic tissue and produced sclerotia and mycelium consistent with S. rolfsii. To confirm identity of the causal fungus, the complete internal transcribed spacer (ITS) rDNA region of the causal fungus was amplified using the primers ITS4 and ITS5 (3) and sequenced. The resulting sequence of 687 bp was uploaded in NCBI (Accession No. JN543691.1). The sequence was 98% similar to sequences of Athelia rolfsii (anamoprh S. rolfsii). This disease has been observed on many species of plants (1, 2). To our knowledge, this is the first report of I. herbstii caused by S. rolfsii in Taiwan or any other part of the world. References: (1) T. T. Chang. Bull. Taiwan For. Res. Inst. 9:191, 1994. (2) Y. N. Wang et al. J. Exp. For. Nat. Taiwan Univ. 20:45, 2006. (3) T. J. White et al. PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, 1990.

Cinnamomum kanehirae, a native tree of Taiwan, is an important tree that hosts popular medicinal fungi. In the winter of 2011, zonate leaf spots were observed at a nursery garden in Wu-Lai, Taiwan. Initial symptoms included small brown lesions on leaves that became larger leaf spots after expanding or fusing together, causing a leaf blight and eventually defoliation. Sporophores on the host were generally hypophyllous but sometimes amphigenous, solitary, erect, easily detachable. The upper portion of the sporophore was considered an individual conidium and consisted of a pyramidal head that was fusiform to ventricose, 320 to 580 μm long and 100 to 130 μm wide at the broadest point. Branches within the pyramidal head were short and compact, and dichotomously or trichotomously branched. The sporophore initials were hyaline, broad, septate, tapering toward an acute apex, and sometimes constricted at the basal septum. Sclerotia were observed in older lesions, grey or black, spherical, and 1 to 2.5 mm in diameter. The fungus was isolated from infected tissue and sporophores, maintained on potato dextrose agar (PDA) at 20°C in darkness. Sclerotia were produced on PDA after 4 to 5 weeks and were irregular or spherical, but sporophores didn't develop on agar medium. The fungus was identified as Hinomyces moricola on the basis of morphological characteristics (1). Koch's postulates were performed by inoculating four 1-year-old, asymptomatic, potted C. kanehirae plants; every plant was inoculated with sporophores from infected leaves on each of five leaves. Four noninoculated plants were kept in separate pots and served as controls. All plants were covered with transparent plastic bags individually and incubated in a growth chamber at 18 to 20°C. Symptoms were observed after 2 to 4 days on every inoculated plant but not on uninoculated plants. The leaf spots were similar to those originally observed. The pathogen was reisolated from spots of inoculated plants. The pathogenicity test was repeated once. H. moricola is known to cause severe defoliation on woody and annual plants, including at least 73 host species and 36 families distributed in the eastern United States and Japan (2). References: (1) N.-S. Tomoko et al. Mycoscience. 47:351, 2006. (2) J. C. Trolinger et al. Plant Dis. Reptr. 62:710, 1978.

Hydrangea macrophylla (Thunb.) Ser., known as mophead hydrangea, is native to Japan and is used as a potted ornamental or is planted for landscaping in gardens worldwide. In May 2011, powdery mildew occurred on potted mophead hydrangea cv. Emerald plants in polyethylene-film-covered greenhouses in Icheon, Korea. Heavily infected plantings were unmarketable, mainly due to purplish red discoloration and crinkling of leaves. Such powdery mildew symptoms on mophead hydrangea in gardens had been often found in Korea since 2001, and the collections (n = 10) were deposited in the Korea University herbarium (KUS). In all cases, there was no trace of chasmothecia formation. Mycelium was effuse on both sides of leaves, young stems, and flower petals. Appressoria were well developed, lobed, and solitary or in opposite pairs. Conidiophores were cylindrical, 70 to 145 × 7.5 to 10 μm, and composed of three to four cells. Foot-cells of conidiophores were straight to sub-straight, cylindric, short, and mostly less than 30 μm long. Conidia produced singly were ellipsoid to oval, 32 to 50 × 14 to 22 μm with a length/width ratio of 1.7 to 2.8, lacked fibrosin bodies, and showed angular/rectangular wrinkling of outer walls. Germ tubes were produced on the perihilar position of conidia. Primary conidia were apically conical, basally rounded to subtruncate, 32 to 42 × 14 to 18 μm, and thus generally smaller than the secondary conidia. The morphological characteristics are consistent with previous descriptions of Oidium hortensiae Jørst. (3,4). To confirm the identification, the complete internal transcribed spacer (ITS) region of rDNA from KUS-F25514 was amplified with primers ITS5 and P3 and directly sequenced. The resulting sequence of 694 bp was deposited in GenBank (Accession No. JQ669944). There was no ITS sequence data known from powdery mildews on Hydrangea. Therefore, this is the first sequence of O. hortensiae submitted to GenBank. Nevertheless, a GenBank BLAST search of this sequence showed >99% similarity with those of Oidium spp. recorded on crassulacean hosts (e.g. GenBank Accession Nos. EU185641 ex Sedum, EU185636 ex Echeveria, and EU185639 ex Dudleya) (2), suggesting their close phylogenetic relationship. Pathogenicity was confirmed through inoculation by gently pressing diseased leaves onto leaves of five healthy potted mophead hydrangea cv. Emerald plants. Five noninoculated plants of the same cultivar served as controls. Plants were maintained in a greenhouse at 22 ± 2°C. Inoculated plants developed signs and symptoms after 6 days, whereas the control plants remained healthy. The fungus present on the inoculated plants was morphologically identical to that originally observed on diseased plants, fulfilling Koch's postulates. Occurrence of powdery mildew disease on mophead hydrangea is circumglobal (1). To our knowledge, this is the first report of powdery mildew disease caused by O. hortensiae on mophead hydrangea in Korea. Powdery mildew infections in Korea pose a serious threat to the continued production of quality potted mophead hydrangea in polyethylene-film-covered greenhouses. References: (1) D. F. Farr and A. Y. Rossman. Fungal Databases, Systematic Mycology and Microbiology Laboratory, ARS, USDA. Retrieved March 19, 2012, from http://nt.ars-grin.gov/fungaldatabases/ . (2) B. Henricot. Plant Pathol. 57:779, 2008. (3) A. Schmidt and M. Scholler. Mycotaxon 115:287, 2011. (4) S. Tanda. J. Agric. Sci. Tokyo Univ. Agric. 43:253, 1999.

Pinus thunbergii Parl., known as black pine, is a pine native to coastal areas of Japan and Korea. Because of its resistance to pollution and salt, it is planted as windbreakers along the coast. In March 2010, needle blight symptoms were found on several trees of black pine in Naju, southern Korea. Further surveys in 2010 and 2011 showed that these symptoms are rather common but disease incidence is less than 1%. Small, circular grayish green spots first appeared on the needles. The spots developed into brown bands reaching 1 to 2 mm long, sometimes with yellow margins. Dark olivaceous to dark grayish stromata were erumpent and conspicuous on the brown lesions in the later stage of disease development. Conidiophores were simple or occasionally branched, 1- to 2-septate, pale brown to olivaceous brown, and smooth walled. Conidia (n = 30) were olivaceous brown to grayish brown, verrucose, thick-walled, mildly curved, allantoid to fusiform, one- to five-septate (mostly three-septate), and 20 to 45 × 3.5 to 5 μm. Morphological characteristics of the fungus were consistent with those of Lecanosticta acicola (Thüm.) Syd. (anamorph of Mycosphaerella dearnessii M.E. Barr), previously known as the causal agent of brown spot needle blight of pines (2,4). The teleomorph was not observed. On potato dextrose agar, single-spore cultures of three isolates were obtained from conidia sporulating on needles. An isolate was preserved at the Korean Agricultural Culture Collection (Accession No. KACC44982). Genomic DNA was extracted using the DNeasy Plant Mini DNA Extraction Kit (Qiagen Inc., Valencia, CA) and the complete internal transcribed spacer (ITS) region of rDNA was amplified and sequenced with the primers ITS1/ITS4. The resulting ITS sequence of 543 bp was deposited in GenBank (Accession No. JQ245448). A GenBank BLAST search produced an exact match for the sequences of M. dearnessii (= L. acicola) on P. mugo Tura from Lithuania (HM367708) and P. radiata D. Don from France (GU214663), with 100% sequence similarity. To conduct a pathogenicity test, a conidial suspension (approx. 2 × 10 5 conidia/ml) was prepared by harvesting conidia from 5-week-old cultures of KACC44982 and sprayed onto the needles of five 3-year-old healthy seedlings. Five noninoculated seedlings of the same age served as controls. Inoculated and noninoculated plants were kept in humid chambers for 48 h in a glasshouse. After 28 days, typical leaf spot symptoms started to develop on the needles of inoculated plants. The fungus, L. acicola, was reisolated from those lesions, confirming Koch's postulates. No symptoms were observed on control plants. The disease has been previously reported on several species of Pinus in the Americas (1) and recently in China (3), Japan (4), and Europe (2). To our knowledge, this is the first report of the Lecanosticta-Pinus association in Korea. Occurrence of the disease in Korea is a new threat to the health of black pine, especially in nursery plots. References: (1) D. F. Farr and A. Y. Rossman. Fungal Databases. Systematic Mycology and Microbiology Laboratory, ARS, USDA. Retrieved from http://nt.arsgrin.gov/fungaldatabases/ December 2011. (2) L. Jankovsky et al. Plant Protect. Sci. 45:16, 2009. (3) C. Li et al. J. Nanjing Inst. For. 1986:11, 1986. (4) Y. Suto and D. Ougi. Mycoscience 39:319, 1998.

Ailanthus altissima (Mill.) Swingle, known as tree-of-heaven, is a deciduous tree belonging to the family Simaroubaceae, which is native to both northeast and central China and Taiwan. The trees often have the ability to replace indigenous plants and disrupt native ecosystems (3). In August 2010, a leaf spot disease was observed on young trees in Yangpyeong, Korea. Field observation in 2010 and 2011 showed that infections are common on 1- or 2-year-old trees. Adult trees were rarely infected. Symptoms usually started at the margin of leaves and expanded into irregular, dark brown leaf spots, eventually causing significant premature defoliation. Representative samples were deposited in the herbarium of Korea University (KUS-F25174 and -F25304). Conidiophores of fungi observed microscopically on the leaf spots were erect, brown to dark brown, single or occasionally in clusters, 80 to 550 × 5 to 8 μm, and mostly arose on the abaxial surface of symptomatic leaves. Conidia were borne singly or in short chains of two to four, ranging from cylindrical to broadest at the base and tapering apically, straight to slightly curved, pale olivaceous brown, 3 to 18 pseudoseptate, 70 to 450 × 8 to 22 μm, each with a conspicuous thickened hilum. On potato dextrose agar, single-spore cultures of five isolates were identified as Corynespora cassiicola (Berk. & M.A. Curtis) C.T. Wei on the basis of morphological and cultural characteristics (1,4). A monoconidial isolate was preserved at the Korean Agricultural Culture Collection (Accession No. KACC45510). Genomic DNA was extracted with the DNeasy Plant Mini DNA Extraction Kit (Qiagen Inc., Valencia, CA). The complete internal transcribed spacer (ITS) region of rDNA was amplified with the primers ITS1/ITS4 and sequenced with an ABI Prism 337 automatic DNA sequencer (Applied Biosystems, Foster, CA). The resulting sequence of 548 bp was deposited in GenBank (Accession No. JN974462). The sequence showed >99% similarity (1-bp substitution) with a sequence of C. cassiicola from Ipomoea batatas (GenBank Accession No. FJ852716). To conduct a pathogenicity test, a conidial suspension (~2 × 10 4 conidia/ml) was prepared by harvesting conidia from 2-week-old cultures of KACC45510 and the suspension sprayed onto the leaves of three healthy seedlings. Three noninoculated seedlings served as control plants. Inoculated and noninoculated plants were kept in humid chambers for 48 h in a glasshouse. After 5 days, typical leaf spot symptoms started to develop on the leaves of all three inoculated plants. C. cassiicola was reisolated from the lesions, confirming Koch's postulates. No symptoms were observed on control plants. C. cassiicola is cosmopolitan with a very wide host range (2). To our knowledge, C. cassiicola has not been reported on A. altissima anywhere in the world. According to field observations in Korea, Corynespora leaf spot was most severe in August and September, especially following a prolonged period of moist weather. C. cassiicola may be a potential biocontrol agent for this highly invasive tree species. References: (1) M. B. Ellis. Dematiaceous Hyphomycetes. Commonwealth Mycological Institute: Kew, Surrey, England, 1971. (2) D. F. Farr and A. Y. Rossman. Fungal Databases. Systematic Mycology and Microbiology Laboratory, ARS, USDA, Retrieved from http://nt.ars-grin.gov/fungaldatabes/ , October 28, 2011. (3) L. B. Knapp and C. D. Canham. J. Torrey Bot. Soc. 127:307, 2000. (4) J. H. Kwon et al. Plant Pathol. J. 17:180, 2001.

Aralia elata (Miq.) Seem., known as Japanese angelica tree, is a deciduous shrub belonging to the Araliaceae, which is native to East Asia. The young shoots have long been used in various dishes in East Asia. Commercial cultivation of this shrub, especially in polytunnels, is expanding in Korea. Several diseases including Sclerotinia rot have been known to be present on this plant (1,2). In early September 2007, leaf spot symptoms were first observed on several trees in Hongcheon, Korea. Microscopic observations revealed that the leaf spots were associated with an Ascochyta sp. Further surveys of the Ascochyta leaf spot showed the occurrence of the disease in approximately 5 to 10% of the trees in the 3 ha of commercial fields surveyed in Chuncheon, Gapyeong, Inje, and Jinju, Korea. Initial symptoms on leaves were circular to irregular, brown to dark brown, becoming zonate, and finally fading to grayish brown in the center with a yellow halo. Representative samples were deposited in the herbarium of Korea University. Conidiomata on leaf lesions were pycnidial, amphigenous, but mostly epiphyllous, immersed or semi-immersed in host tissue, light brown to olive brown, and 60 to 200 μm in diameter. Ostioles were papillate, 20 to 35 μm wide, and surrounded by a ring of darker cells. Conidia were hyaline, smooth, cylindrical to clavate, straight to mildly curved, slightly constricted at the septa, medianly one-septate, sometimes aseptate, 8 to 16 × 2.5 to 3.5 μm, and contained small oil drops. These morphological characteristics were consistent with the previous reports of Ascochyta marginata J.J. Davis (3,4). A monoconidial isolate was cultured on potato dextrose agar (PDA) plates and accessioned in the Korea Agricultural Culture Collection (Accession KACC43082). The conidia were readily formed on PDA. Inoculum for the pathogenicity tests was prepared by harvesting conidia from 30-day-old cultures of KACC43082 and a conidial suspension (approximately 2 × 10 6 conidia/ml) was sprayed onto leaves of three healthy seedlings. Three noninoculated seedlings served as controls. Inoculated and noninoculated plants were covered with plastic bags for 48 h in a glasshouse. After 7 days, typical leaf spot symptoms started to develop on the leaves of the inoculated plants. The fungus, A. marginata, was reisolated from those lesions, confirming Koch's postulates. No symptoms were observed on control plants. Previously, the disease was reported in Japan (4) and China (3). To our knowledge, this is the first report of A. marginata on Japanese angelica trees in Korea. According to our field observations in Korea, the Ascochyta leaf spot mostly occurred on plants growing in a humid environment, especially during the rainy season. The seedlings as well as the trees growing in sunny, well-ventilated plots were nearly free from this disease. Therefore, the growing conditions seemed to be the most important factor for the development and severity of the disease. References: (1) C. K. Lee et al. Plant Pathol. J. 26:426, 2010. (2) S. H. Lee et al. Diseases of Japanese Angelica Tree and Their Control. Research Report 08-10. Korea Forest Research Institute. Seoul, Korea, 2008. (3) J. Sun et al. Acta Mycol. Sin. 14:107, 1995. (4) M. Yoshikawa and T. Yokoyama. Mycoscience 36:67, 1995.

During a survey conducted in August 2009 in northern Norway, symptoms typical for red band needle blight (1) were observed in four young Scots pine (Pinus sylvestris) stands. The stands, less than 15 years old, were located in humid sites near rivers in Bardu and Målselv municipalities, Troms County. Many of the oldest needles (2- to 3-yearsold) in the lower part of young trees were partially or completely brown, but still attached, and red bands could be observed. Aggregations of conidial stromata were often seen in the red bands. Conidia were hyaline, smooth, thin walled, and filiform, 1.9 to 2.6 μm wide and 12 to 36 μm long. Isolations were made from conidiomata and the identity of Mycosphaerella pini was confirmed by partial sequencing of the internal transcribed spacer (ITS) region of a sample from Målselv (69°00'N, 18°51'E) (GenBank Accession No. JF796109). In June 2010, a survey was done in southeastern Norway where nearly 100 stands with young Scots pine, up to 20 years old, were inspected and typical symptoms of red band needle blight were observed in 10 stands in three municipalities in Hedmark County (Eidskog, Kongsvinger, and Trysil), less than 25 km from the Swedish border, and in one stand in Buskerud County (Nedre Eiker). Lower branches of up to 5 m tall trees had symptoms of red band needle blight, mainly on the oldest needles. In the red bands, acervuli of Dothistroma septosporum, the anamorph of M. pini, appeared. Typical conidia from acervuli were germinated in water agar and resulting mycelium was transferred to modified orange serum agar. Two isolates were sequenced as above and both herbarium samples and isolates (Kongsvinger, 60°06'N, 12°04'E; GenBank Accession No. JF796108 and Trysil, 61°14'N, 12°22'E; GenBank Accession No. JF796107) were deposited at the Norwegian Forest and Landscape Institute. To fulfill Koch's postulates, symptoms were reproduced by artificial inoculation onto 1-year-old Scots pine seedlings. In June 2010, a pooled conidial suspension (2.4 to 3.8 × 10 3 conidia per ml) from two single-conidium cultures was sprayed to runoff onto 128 seedlings and 64 seedlings were mock sprayed with distilled water. First symptoms (brown segments and red bands) appeared on inoculated seedlings 1 month later and acervuli appeared after another 6 to 8 weeks. M. pini was reisolated from the acervuli. Three months after inoculation, 90% of inoculated seedlings showed symptoms while all uninoculated seedlings were healthy. Damage caused by M. pini has increased in the northern hemisphere during the last 15 to 20 years, possibly because of climate change (4). In 2006, the fungus was recorded in Estonia (2), in 2008 in Finland (3), and by 2009, the disease had spread over large areas in Finland including the region near the Norwegian border in the north. The disease has been in Sweden for a few years (J. Stenlid, personnel communication). In southern Norway, the disease has mainly been observed near the Swedish border so here the disease may originate from Sweden. So far, however, only small areas of Norway have been surveyed. Both natural spread and human transport dissemination may be occurring. References: (1) Anonymous. OEPP/EPPO Bull. 35, 303, 2005. (2) M. Hanso and R. Drenkhan. Plant Pathol. 57:170, 2008. (3) M. Müller et al. Plant Dis. 93:322, 2009. (4) A. Woods et al. BioScience 55:761, 2005.

A survey of nematodes on Pinus densiflora in Namyangju City, Gyeonggi Province, Korea was conducted in 2008. Namyangju is located in an area with pine wilt caused by Bursaphelenchus xylophilus and monitoring of wilt has been conducted periodically. Nematodes were extracted from wood chips by the Baermann's funnel method and were cultured on a medium of Botrytis cinerea. During the survey, B. xylophilus and B. thailandae were detected. B. thailandae was found in 20% of the trees tested and usually was found alone without B. xylophilus. Population density of B. thailandae ranged from 8,000 to 15,000 nematodes per 100 g of wood chips. The species was identified by morphology and molecular characterization. B. thailandae was differentiated from B. xylophilus by slight swellings of the stylet knobs, protruding vulval flaps and pointed tail in females, and the male spicule with distinctive shading in the dorsal region. Morphometric data was obtained by measurements of 20 females and 10 males: female, body length = 951.3 ± 56.6 μm, a = 31.8 ± 1.9, b = 10.8 ± 0.9, c = 23.4. ± 0.8, V = 76.2 ± 0.8, stylet length = 14.5 ± 0.6 μm, length of postuterine sac = 90.3 ± 13.5 μm; male, body length = 838.0 ± 71.5 μm, a = 31.1 ± 2.1, b = 5.2 ± 0.5, c = 30.4 ± 2.7, stylet length = 13.5 ± 1.1 μm, spicules length = 16.5 ± 0.7 μm. Measurements were compared with the original description of B. thailandae reported by Braasch and Braasch-Bidasak (1), which showed that the Korean isolate was larger in most body sizes. For molecular diagnosis, the internal transcribed spacer (ITS) and D2-D3 rDNA were amplified by PCR (US/PTC-0220; Bio Rad, Hercules, CA). The sequences of ITS and D2-D3 rDNA of B. thailandae from P. densiflora showed 98 and 99% homology to those of B. thailandae from GenBank Accession Nos. AM157746 and DQ497184, respectively. B. thailandae was originally described on Pinus merkusi in Pai, North Thailand (1) while Ningbo Entry-Exit Inspection and Quarantine Bureau in China reported a detection of B. thailandae in the imported packaging wood from Hong Kong, Japan, Korea, Italy, and the United States (2). However, packaging wood is a circulating product and the establishment of B. thailandae in those countries is not confirmed. The pathogenicity of B. thailandae on coniferous trees remains to be determined. To our knowledge, this is the first report of B. thailandae on P. densiflora in a natural area in Korea. References: (1) H. Braasch and R. Braasch-Bidasak. Nematology 4:853, 2002. (2) J. Gu et al. For. Pathol. 36:323, 2006.

The genus Bursaphelenchus Fuchs, 1937 contains approximately 90 species (3) that are morphologically similar. Pine wood nematode, Bursaphelenchus xylophilus (4) Nickle, 1970, is the causal organism of pine wilt disease and accurate identification is essential for diagnosis of the disease. In Korea, pine wilt disease was first reported in 1988 and devastated 6,800 ha of pine forest through 2008. For a survey of trees with pine wilt disease, wood samples were taken randomly from dead Pinus koraiensis in Namyangju, Gyeonggi Province in Korea. The extracted nematodes from dead trees were maintained in culture on Botrytis cinerea and morphological characteristics were observed with an inverted light microscope (Leica DE/DMI 3000B). Identification of Bursaphelenchus spp. based on morphological characteristics is difficult, especially for identification of juveniles that carry few morphological features for species identification. The internal transcribed spacer (ITS) region in ribosomal DNA provides useful molecular diagnostic markers for this genus (1). The nematodes were provisionally identified as Bursaphelenchus pinophilus based on the characteristic long and arcuate body shape, male spicule with distinctive rostrum and small cucullus, female vulval flap, and mucronate conical tail. Other Bursaphelenchus spp. with vulval flaps and spicules with cucullus are B. xylophius, B. mucronatus, B. abruptus, and B. pinophilus. For molecular diagnosis, DNA was extracted from more than 30 individual nematodes with a DNeasy Kit (Qiagen, Valencia, CA) and ITS regions 1, 2, and 5.8S in rDNA were amplified by PCR (US/PTC-0220; Bio Rad, Hercules, CA). The ITS-restriction fragment length polymorphism pattern was consistent with that of B. pinophilus (2). The ITS rDNA sequence of B. pinophilus from Korean pines had a 98% sequence homology to that of B. pinophilus in GenBank (Accession No. AM160664). The pathogenicity of B. pinophilus has not been determined. To our knowledge, this is the first report of B. pinophilus on P. koraiensis, but it was previously reported from Poland, Germany, and Portugal on P. sylvestris and P. pinaster (1). References: (1) H. Braasch. EPPO Bull. 31:127, 2001. (2) W. Burgermeister et al. Russ. J. Nematol. 13:29, 2005. (3) R. Sriwati et al. Nematology 10:1, 2008. (4) G. Steiner and E. M. Buhrer. J. Agric. Res. 48:946, 1934.

Tulip tree (Liriodendron tulipifera) is one the major tree species in Korean plantations, but it originated from North America. Bursaphelenchus doui was collected from the wood of dead tulip trees located at Wanju in Chonnam Province, Korea. Nematodes were maintained in fungal medium culture (Botrytis cinerae) on potato dextrose agar. B. doui is morphologically close to B. xylophilus, a causative organism of pine wilt disease, and identification to species is difficult. However, B. doui differs from the other species of the xyophilus group by the larger spicule (33.8 to 43.3 μm) (1). For accurate species identification, both morphology and molecular biological methods were applied. Morphological observations showed lip region 3.7 μm high and offset by a constriction, median bulb well developed, esophageal gland overlapping intestine dorsally, vulval flap present, tail terminus with distinct mucro. Males ventrally curved by fixation, spicules pared, and large with small, cucullus, oval-shaped bursa. Measurements of 20 females and 10 males (female; body length = 901.7 ± 60.5 μm, a = 34.3 ± 3.1, b = 10.4 ± 1.5, c = 23.0 ± 2.3, V = 77.1 ± 2.0, stylet length = 14.3 ± 0.4 μm, tail length = 39.5 ± 4.2 μm, length of postuterine sac = 104.6 ± 7.8: male; body length = 790.4 ± 40.6 μm, a = 34.4 ± 2.7, b = 10.8 ± 1.7, c = 22.7 ± 1.3, stylet length = 14.3 ± 0.3 μm, tail length = 34.8 ± 1.9 μm, spicules length = 39.5 ± 4.1 μm) were close to the original description of B. doui by Braasch et al. (1). For molecular diagnosis, DNA was extracted from more than 30 individual nematodes with a DNeasy Kit (Qiagen, Valencia, CA) and the internal transgenic spacers (ITS) 1, 2, and 5.8S regions in rDNA were amplified by PCR (US/PTC-0220; Bio Rad, Hercules, CA). ITS-restriction fragment length polymorphism (RFLP) can discriminate closely related species by using five different restriction enzymes (2). ITS-RFLP patterns obtained with these enzymes were the same as reported by Braasch et al. (1). B. doui previously has been detected in Korean wooden packages imported to China (1). However, most production of Korean wooden packages depends on imported coniferous trees from other countries. Although B. doui has been reported in Japanese red pine (Pinus densiflora) in Japan (3), the natural distribution of B. doui in Korea is unclear. On the basis of morphological and molecular biological information, we identify this nematode as B. doui. To our knowledge, this is the first report of B. doui on tulip tree and in a natural area in Korea. References: (1) H. Braasch et al. Russ. J. Nematol. 12:19, 2004. (2) W. Burgermeister et al. Russ. J. Nematol. 13:29, 2005. (3) N. Kanzaki et al. Nematology. 10:69, 2008.

Red band needle blight of pines caused by Mycosphaerella pini (anamorph Dothistroma septosporum) has recently been recorded on Scots pine (Pinus sylvestris) at 14 rural districts in southern and central Finland. Scots pine is the most common and commercially most important tree species in Finland. Red bands with aggregations of conidial stromata on otherwise brown attached needles were frequently encountered on saplings and young trees in dense stands and sporadically on lower twigs of mature trees within 2 m of the ground. These symptoms and signs, typical for M. pini (1), were also observed on needles of P. contorta and P. cembra, which occur in Finland in low frequency. Symptoms of red band needle blight and abundant conidial stromata were found in March and April of 2008 after a mild and rainy winter. After this time, the frequency at which fresh acervuli were observed decreased. Conidia were isolated after squeezing conidial stromata into a drop of sterile water and rinsing out the drop onto water agar from where single conidia were picked up from under the microscope with a modified Pasteur pipette. The conidia were hyaline, smooth, thin walled, filiform, 2.0 to 2.7 (2.4) μm wide, and 15 to 37 (29.4) μm long. Germination of the conidia on water agar was 100%. The cultures grew slowly and reached a diameter of 4 to 10 mm within 3 weeks on modified orange serum agar (2) at 20°C and abundantly produced conidia. Complete sequences of the internal transcribed spacer (ITS) region including the 5.8S rRNA gene were obtained for three isolates from different rural districts: Hartola (61°34'N, 26°01'E), Kangasniemi (61°59'N, 26°39'E), and Suonenjoki (62°37'N, 27°07'E). These sequences are deposited in GenBank with Accession Nos. EU834294, EU834295, and EU834296 and are identical to each other and to more than 50 M. pini sequences in GenBank, including those of several Estonian and Austrian isolates. These isolates are deposited in the culture collection of the Finnish Forest Research Institute with identifiers Dot1, Dot2, and Dot8. Symptoms were reproduced after inoculation of 1-year-old Scots pine seedlings growing in seedling trays with 115 cm 3 cavities. A conidial suspension (5 to 6·× 10 3 conidia ml -1 ) was prepared from two single-conidial cultures (Dot10 and Dot15), combined, and sprayed during July 2008 onto 192 seedlings until needles looked completely wet. Sixty-four seedlings were sprayed with distilled water as a control treatment. Seedlings were incubated outdoors in Suonenjoki and covered with a transparent plastic hood for the first 5 days after inoculation. The first symptoms (brown segments and red bands on needles) appeared on inoculated seedlings 1 month later, and conidial stromata appeared after another 2 to 4 weeks. M. pini was reisolated from the acervuli of 10 sample needles. Three months after inoculation, all inoculated seedlings showed symptoms while all noninoculated seedlings were healthy. It is possible that M. pini has spread recently from the south since it was identified for the first time in Estonia 2 years earlier (3). Although the Gulf of Finland separates Finnish pine forests from Estonian pine forests by approximately 50 to 100 km, spores may have been aerially disseminated over this distance. Alternatively, introduction of M. pini to Finland may have occurred on imported seedlings. References: (1) Anonymous. OEPP/EPPO Bull. 35, 303, 2005. (2) M. Hanso and R. Drenkhan. Plant Pathol. 57:170, 2008. (3) M. M. Müller et al. Mycol. Res. 98:593, 1994.

More than 70 species of Bursaphelenchus have been reported and they are morphologically very similar. The pine wood nematode (Bursaphelenchus xylophilus) is a causal agent of pine wilt and accurate identification is essential for diagnosis of the disease. However, many other saprophytic nematodes are found in dead trees and some of them have high morphological similarity to B. xylophilus. B. mucronatus is commonly found in dead pine trees and is distinguished from B. xylophilus only by the presence of a distinct mucro in the female tail (3). However, natural populations of B. xylophilus show variation in tail morphology and some of them have a small lump on the end of the tail that looks like a short mucro, which could lead to misidentification. B. mucronatus has been reported to have two genotypes known as the East Asian type and the European type (2). The European type has a more rounded tail with a mucro, which is much more similar to B. xylophilus than the East Asian type. Molecular identification by internal transcribed spacer restriction fragment length polymorphism (ITS-RFLP) can distinguish these two genotypes clearly by using five different restriction enzymes (2). In Korea, we collected wood samples from dead Pinus koraiensis located at Pocheon, Gyeonggi Province in April, 2007 and nematodes were extracted by a modified Baermann funnel method. After 24 h, nematodes were collected and morphology was observed under an inverted light microscope (Leica DE/DMI 3000B, Wetzlar, Germany). Morphology was characterized by a typical Aphelenchoid-type esophagus, head constriction, female vulva flap, post uterine sac, female tail with mucro, and males with arched-shaped spicules. The tail was rounded with a long mucro >4 μm. For molecular diagnosis, DNA was extracted from single individual nematodes by using a DNeasy Kit (Qiagen, Valencia, CA) and the ITS 1 and 2 and 5.8S regions in rDNA were amplified by PCR (US/PTC-0220; Bio-Rad, Hercules, CA). ITS-RFLP patterns were analyzed and nucleotide sequences were compared with sequences of B. mucronatus already reported in GenBank (Accession Nos. AM179514, BMU93554, and DQ841162). The ITS-RFLP pattern of individuals matched the European type of B. mucronatus and was differentiated from the East Asian type by RsaI and HaeIII digestion (2). The ITS DNA sequence of nematodes from Korean pines was >98% identical to B. mucronatus in GenBank. The European type of B. mucronatus was consistently isolated from dead trees, but the pathogenicity of the European type of B. mucronatus on Korean pine is not yet clear. To our knowledge, this is the first report of the European type of B. mucronatus species on P. koraiensis in Korea, but it is already distributed in certain locations of Japan (4), China, and Europe (1). References: (1) H. Braasch et al. Nachrbl. Dtsch. Pflanzenschutzd. 51:312, 1999. (2) W. K. Burgermeister et al. Russ. J. Nematol. 13:29, 2005. (3) Y. Mamiya and N. Enda. Nematologica 25:353, 1979. (4) K. Togashi et al. Jpn. J. For. Res. 13:127, 2008.

Pine wilt disease is one of the most important forest tree diseases, especially in the East Asian countries of Japan, China, and Korea. The causal agent, Bursaphelenchus xylophilus (3), is transmitted by the insect vectors, pine sawyer beetles (Monochamus spp.). The vectors mainly attack coniferous trees and the infected trees die within several weeks. In Korea, pine wilt disease was first reported in Busan City in 1988, and now, the damaged area covers 7,820 ha and more than 60 cities in Korea. The main host trees are Pinus densiflora and P. thunbergii, which are the most common pines distributed in Korea. In 2006, however, we found pine wilt disease in a forest of P. koraiensis located in Gwangju City in Gyeonggi Province. Symptoms were systemic and leaves turned brown or yellowish. Wood samples were collected from the affected trees, and nematodes were extracted by a modified Baermann's funnel method. After 24 h, nematodes were collected from wood chips, and morphology was observed with an inverted light microscope (Leica DE/DMI 3000B, Wetzlar, Germany). Morphology was characterized by a typical Aphelenchoid-type esophagus, head constriction, female vulva flap, female tail, and a male spicule shape similar to B. xylophilus. For more accurate identification, DNA was extracted from individual nematodes with a DNeasy Kit (Qiagen, Valencia, CA). The internal transcribed spacers (ITS) 1 and 2 and 5.8S regions were amplified by PCR (1). Sequenced nucleotide information was compared with the sequences of B. xylophilus already reported in GenBank (Accession Nos. AB294736, AB277208, AM 157747, AY 347913, and BXU92464). ITS DNA sequences of the nematode from Korean pine was >99% identical to B. xylophilus in GenBank. The B. xylophilus from Korean pine tree was also successfully cultured in Botrytis cinerea medium and pathogenicity was tested from June to October 2007. More than 95% mortality was observed with the inoculation of 20 replicate 15-year-old trees of P. koraiensis and P. densiflora with 15,000 nematodes per tree. Therefore, we confirmed that pine wilt disease occurred in P. koraiensis in Korea. P. koraiensis is an endemic species in Korea and distribution is limited to the northern Korean Peninsula and some locations in Russia. It has been shown that P. koraiensis is susceptible to the pine wood nematode by an inoculation test in Japan (2); however, to our knowledge, this is the first report of pine wilt disease on P. koraiensis under field conditions in Korea. References: (1) W. K. Burgermeister et al. Russ. J. Nematol. 13:29, 2005. (2) K. Futai and T. Furuno. Bull. Kyoto Univ. For. 51:3, 1979. (3) G. Steiner and E. M. Buhrer. J. Agr. Res. 48:946, 1934.

Since the late 1970s, chestnut (Castanea spp.) has been one of the most commonly cultivated nuts for human consumption in Korea. In 1998, as much as 100,000 t of chestnut seeds were produced from 79,000 ha of plantations for export (2). Most cultivated chestnuts are hybrids of Castanea crenata and C. mollissima that have resulted in 27 cultivars commonly grown in Korea. In 2004, dead trees of two cultivars (Tsukuba and Ginyose) from different locations were found with black ooze emanating from reddish, sunken tissues on the trunks. When the bark was peeled off, a distinct necrotic region was observed on the basal trunk with the discoloration extending up and girdling the trunk. In November 2006, a Phytophthora species was isolated from the necrotic areas with a CARP selective medium (4). Eleven isolates were obtained from three locations: Hadong, Hapcheon, and Youngqwang. The isolates produced numerous homothallic oogonia (34.0 to 46.2 × 21.9 to 26.7 μm) with warty protuberances on the surface. Antheridia were amphigynous with long, funnel-shaped stalks at the base of the oogonia. The formation of papillate, ovoid to obpyriform sporangia (17.0 to 38.9 × 14.6 to 29.2 μm) was induced by cold treatment in filtered (through 25-μm particle retention) creek water or deionized water. Chlamydospores were not observed. Comparison of the rDNA ITS sequence using ITS1/4 (3) showed 99.6% similarity to P. katsurae (GenBank Accession No. AF266771) with three base pair differences. All eleven isolates showed identical ITS sequences. Pathogenicity studies were conducted on excised three 15-cm-long × 5-cm-diameter logs from each of three chestnut cultivars (Moriwase, Parkmi 2, and Ibuki). Bark (5 mm in diameter) was taken with a cork borer on each log followed by inoculation with a 5-mm agar disk of two isolates, PH.K01 and PH.K07. The logs were placed in a moist chamber for 7 days. Noninoculated controls consisted of log sections from each cultivar treated with agar disks. The pathogencity test was repeated three times. The entire log of cv. Parkmi 2 became necrotic, whereas the other two cultivars developed only small lesions (P < 0.0001). The noninoculated control logs of each cultivar did not develop lesions and no pathogen was reisolated from them. This suggests that cultivars differ in susceptibility. P. katsurae (synonym = P. castaneae) was first described from Japan in 1931. P. cambivora, P. cinnamomi, and P. katsurae are commonly responsible for ink disease on chestnut species in Europe, the United States, and Asia (1). The impact of P. katsurae on chestnut production in Korea is currently unknown. References: (1) A. Boutard et al. The West. Chestnut. 3:6, 2001. (2) S. H. Lee et al. J. Korean For. Soc. 95:61, 2006. (3) E. Oh et al. Forest Pathol. 36:388, 2006. (4) T. J. White et al. Page 315 in: PCR Protocols. Academic Press Inc., New York, 1990.

Japanese serissa (Serissa japonica (Thunb.) Thunb.) is a very popular ornamental in Taiwan. During the summer of 2005, serissa plants in a central Taiwan nursery had decaying roots, leaf yellowing, and were wilting. Wilted plants had white fan-like mycelium under the bark. The disease caused 70% loss of seedlings at the nursery. Associated synnemata were rigid, erect, dark, setaceous, 0.8 to 2.1 mm long, 90 to 200 μm wide, and tapering to enlarged whitish gray heads composed of geniculate conidiophores and conidia. Conidia were 3.1 to 5.8 × 2.6 to 3.4 μm, unicellular, hyaline, and subglobal with a truncated base. Root rots were washed, disinfested for 1 min in 0.5% NaOCl, cut into 3 mm 3 pieces, plated on Merck (Darmstadt, Germany) potato dextrose agar (PDA) amended with 100 ppm of ampicillin (Sigma, St. Louis, MO), and incubated at 24°C in the dark until hyphae emerged. Single hyphal tips were transferred to PDA, and two isolates were established as pure cultures. Mycelia were cut, stained with 1% cotton blue in lactophenol, and pear-shaped hyphal swellings adjacent to the septa were observed. According to these hyphal, synnematal, and conidial characteristics, the fungus was identified as Dematophora necatrix Hartig, the anamorph of Rosellinia necatrix Prill. Inoculum for pathogenicity tests were produced on oat-wheat medium composed of 20 ml of oat grain and 20 ml of wheat grain, mixed, and soaked in water for 3 h. The grains were placed in 200-ml flasks, autoclaved at 121°C for 30 min, inoculated with two isolates of D. necatrix separately, and grown for 14 days. Six 3-month-old Japanese serissa seedlings were grown in pots. The grain inoculum was added to unsterilized field soil and the plants were transplanted into this mix. Control plants were transplanted into a similar mix without the inoculum. Two replicates were used for a total of 24 inoculated plants and 24 control plants. All plants were kept in a growth chamber at 25 to 35°C with 20 min of irrigation per day, 12 h of irradiation, and relative humidity at more than 95%. Inoculated plants developed root rots after 1 month, and after 4 months, all plants were dead, while control plants remained healthy. D. necatrix was reisolated, hyphal characteristics confirmed, and synnemata were observed on collars of dead plants. The teleomorph was not formed by our cultures, and the identification of Rosellinia necatrix was confirmed by molecular studies. The nuclear ribosomal internal transcribed spacer (ITS) amplified with two primers, ITS1 and ITS4, from our representative isolate demonstrated 99.63, 99.81, and 99.27% similarity to two R. necatrix isolates from Japan and one R. necatrix isolate from Italy, respectively. This disease has been reported on many species of plants (1), but to our knowledge, this is the first report of white root rot of Japanese serissa seedlings caused by R. necatrix in Taiwan. Reference: (1) S. T. Su et al. List of Plant Diseases in Taiwan. The Phytopathological Society of the Republic of China, 2002.

Silvery messerschmidia, Messerschmidia argentea (L.) Johnston, of the Boraginaceae, is indigenous to Taiwan and grown as an ornamental, for windbreaks, or as a shade tree. During the summer of 2005, a sudden wilt of 1-year-old plants was observed in a nursery in central Taiwan. Initial symptoms included stem necrosis at the collar, leaf yellowing, and tan discoloration of leaves. As stem necrosis progressed, infected plants wilted, defoliated, and died. Necrotic tissues were covered with whitish mycelium with clamp connections that formed reddish brown spherical (1 to 2.2 mm in diameter) sclerotia. A fungus was consistently recovered from the interface of diseased and healthy stem tissue, disinfested for 1 min in 0.5% NaOCl, and plated on Difco (Sparks, MD) potato dextrose agar (PDA) amended with 100 ppm of ampicillin. Pure cultures were prepared by transferring single hyphal tips to PDA, and Sclerotium rolfsii (Sacc.) was identified (1). Pathogenicity of two S. rolfsii isolates was confirmed by inoculating 3-month-old silvery messerschmidia seedlings grown in pots. Inoculum consisted of a single agar disk of a 7-day-old culture used per pot or a single sclerotium produced in 10 days on PDA and added per pot. Both the mycelium on the 0.5-cm-diameter agar plug and the sclerotium touched the base of the plant stem. Four plants were inoculated with mycelia, four with sclerotia, and four were noninoculated controls. All plants were kept in a growth chamber at 25 to 35°C with relative humidity of more than 95%. Initially, the basal stems were covered by whitish mycelia growth with a fanlike pattern from the inoculum, and brown, water-soaked necrotic lesions developed near the soil line. Inoculated plants developed symptoms within 4 days, wilted gradually in 7 days, and all were eventually killed in 11 days. Plants inoculated with sclerotia developed disease at a slower rate and control plants remained symptomless. Sclerotia developed on diseased tissues and S. rolfsii was reisolated. This disease has been observed on many species of plants (2), but to our knowledge, this is the first report of southern blight of silvery messerschmidia seedlings caused by S. rolfsii in Taiwan. References: (1) R. K. Jones and D. M. Benson, eds. Diseases of Woody Ornamentals and Trees in Nurseries. The American Phytopathological Society, St. Paul, MN, 2001. (2) Y. P. Tsai, ed. List of Plant Diseases in Taiwan. The Plant Protection Society of the Republic of China and The Phytopathological Society of the Republic of China, 1991.

Phytophthora ramorum was found for the first time in Finland during the spring of 2004 on marketed plants of Rhododendron spp. originating in other EU member states. During August of 2004, the pathogen was also found in one Finnish nursery on German Rhododendron catawbiense plants and several Finnish Rhododendron spp. cultivars. P. ramorum was detected by species-specific PCR and isolated (1). It was first characterized by an abundant production of chlamydospores on PARP and V8 agar, absence of oogonia and antheridia, and elongate, ellipsoid, deciduous, semipapillate sporangia produced in soil extract water (3). A partial sequence of the β-tubulin gene was identical to that of P. ramorum deposited in GenBank. Despite strict regulations governing the movement of plants, the pathogen has been found every year since 2004 on materials transported to Finland from other EU countries. A total of 586 samples were taken from symptomatic plants of several susceptible species from 2004 to 2006. P. ramorum was detected in 51 rhododendron samples and the number of the outbreak sites was 28. In domestic plant production, P. ramorum was found in only one nursery. The infected plants in this nursery were destroyed in 2005 according to the EU regulation 2004/426/EG. During the 2006 growing season, 84 samples from trace-forward inspections and reinspections of the nursery were tested and P. ramorum was not detected in any of the samples. In 2005, surveys for P. ramorum on Finnish Rhododendron spp. cultivars with necrotic lesions on leaves and blackened tips yielded, in addition to P. ramorum, another Phytophthora sp. On V8 agar, this homothallic species showed a stellate growth pattern with sparse aerial mycelium. Oogonia had both paragynous and amphigynous antheridia, and sporangia produced in soil extract water were ellipsoid in shape and semipapillate. A 763-bp segment of the β-tubulin gene was sequenced and was identical to the β-tubulin sequence of P. inflata strain IMI342898 (GenBank), which was isolated in 1990 from Syringa sp. in the UK. It is likely that this P. inflata strain has been spreading in Europe with the ornamental plant trade. To fulfill Koch's postulates, rhododenrdon plants were inoculated (2) with P. inflata or P. ramorum, typical symptoms observed, and the pathogens were reisolated from inoculated plants. Both Phytophthora species also caused necrotic lesions on Alnus glutinosa, A. incana, and Betula pendula. Pinus sylvestris was resistant to both Phytophthora spp., whereas Picea abies was susceptible to P. inflata but not P. ramorum. References: (1) EPPO Bull. 36:145, 2006. (2) E. Hansen et al. Plant Dis. 89:63, 2005. (3) S. Werres et al. Mycol. Res. 105:1155, 2001.

Formosan michelia (Michelia compressa (Maxim.) Sargent) is a native, giant evergreen tree in Taiwan. This species is used for afforestation, provision of shade in domestic situations, used in parks, and also for furniture. During the summer of 2004, a sudden wilt of 1-year-old plants was observed in a nursery of northern Taiwan. Initial symptoms included stem necrosis at the soil line, yellowing, and tan discoloration of leaves. As stem necrosis progressed, infected plants wilted and died. Necrotic tissues were covered with whitish mycelium that differentiated into reddish brown spherical (1 to 2 mm in diameter) sclerotia. Sclerotium rolfsii was consistently recovered from the surface of symptomatic stem sections that were disinfected for 1 min in 0.5% NaOCl and then plated on potato-dextrose agar amended with 100 ppm ampicillin. Pathogenicity of two S. rolfsii isolates was confirmed by inoculating 1-year-old Formosan michelia seedlings grown in pots. Inoculum consisted of mycelium and sclerotia of the pathogen placed on the soil surface around the base of each plant. Noninoculated plants served as controls. All plants were kept in a growth chamber at 25 to 35°C with relative humidity >95%. Inoculated plants developed symptoms within 14 days while control plants remained symptomless. Sclerotia developed on infected tissues, and S. rolfsii was reisolated from symptomatic tissues. This disease has been observed on many species of plants (1), but to our knowledge, this is the first report of southern blight of Formosan michelia seedlings caused by S. rolfsii in Taiwan. Reference: (1) Y. P. Tsai, ed. List of Plant Diseases in Taiwan. The Plant Protection Society of the Republic of China and The Phytopathological Society of the Republic of China, 1991.

Island ash (Fraxinus formosana Hay.) is a large, semideciduous tree in Taiwan. It is used for forestation, a shade tree, and producing wood for furniture. During the summer of 2001, a sudden wilt of 1-year-old plants was observed in a nursery in northern Taiwan. Initial symptoms included stem necrosis at the soil line and yellowing and tan discoloration of the leaves. As stem necrosis progressed, infected plants wilted and died. Necrotic tissues were covered with white mycelium that differentiated into reddish brown, spherical (1 to 2 mm in diameter) sclerotia. Sclerotium rolfsii was consistently recovered from the surface of symptomatic stem sections that were disinfected for 1 min in 0.5% NaOCl and then plated on potato dextrose agar (PDA) amended with 100 ppm of ampicillin. Pathogenicity of two S. rolfsii isolates was confirmed on 1-year-old island ash seedlings grown in 12.7 cm- (5-in) plastic pots in a sterilized mixture of peat moss and vermiculite (3:1). Seedlings were inoculated with mycelia and sclerotia of the pathogen grown on PDA. Three plants each were inoculated with four disks (5 mm) of agar with mycelium and three were inoculated with 10 sclerotia that were placed on the soil surface around the base of each plant. Noninoculated plants served as controls. All plants were kept in a growth chamber at 25 to 35°C and >95% relative humidity. The test was repeated once. All inoculated plants developed symptoms within 14 days, while control plants remained symptomless. Sclerotia developed on infected tissues, and S. rolfsii was reisolated from symptomatic tissues. This disease has been observed on many species of plants (1), but to our knowledge, this is the first report of Southern blight of Island ash seedlings caused by S. rolfsii in Taiwan. Reference: (1) Y. P. Tsai ed. List of Plant Diseases in Taiwan. The Plant Protection Society of the Republic of China and The Phytopathological Society of the Republic of China, 1991.

Members of the Heterobasidion annosum (Fr.) Bref. complex are among the most important pathogens in coniferous forests of Europe and North America. Three intersterile groups (P, S, and F) have been found in this complex from Europe (1) and were recently segregated into three species based on intersterility, host preferences, and morphology (4). In a survey of wood-rotting fungi in China in 2002, Heterobasidion spp. were found on Tsuga chinensis (Franch.) Pritz and T. dumosa (D. Don) Eichl. in natural forests from the northern Sichuan Province of southwestern China (32°43' to 33°11' N, 103°50' to 103°53' E.). Basidiocarps of the fungus were relatively common on decayed wood in roots of dead trees, stumps, and fallen trunks. We collected four basidiocarps (Dai 4045, 4051, 4214, and 4224 in the Institute of Applied Ecology, Chinese Academy of Sciences, IFP) from three stands of mixed coniferous forests and made 40 homokaryotic, single-basidiospore cultures (02046, 02047, 02050, and 02051 in the Finnish Forest Research Institute). Two homokaryons from each basidiocarp were paired with homokaryotic tester strains of European H. annosum (P group), H. parviporum Niemelä & Korhonen (S group), and H. abietinum Niemelä & Korhonen (F group). The pairings showed that the progeny from the four basidiocarps are H. parviporum. The Chinese isolates did not form clamp connections with H. annosum sensu stricto, and a strong demarcation line developed in all these pairings. In contrast, the Chinese isolates formed clamp connections in almost every pairing with European H. parviporum, the clamp connections developed in both sides of the pairings, and no distinct demarcation line was present in most of these pairings. The Chinese homokaryons were also compatible with European H. abietinum, but in most of these pairings, clamp connections were found in the isolate from China but not in the European tester, and a demarcation line was present in most of the pairings. In contrast to H. annosum sensu stricto, the Chinese basidiocarps had smaller pores (4.5 to 6 per mm versus 3 to 4.5 per mm), and a thin tomentum on the pileal surface in contrast to the basidiocarps of H. abietinum. Previously, H. parviporum was found in Asia on coniferous hosts such as Abies, Larix, Picea and Pinus spp. (2). The North American S group of H. annosum sensu lato attacks species of Tsuga spp. in western North America (3), but to our knowledge, this is the first report of H. parviporum on native species of Tsuga spp. outside North America. References: (1) P. Capretti et al. Eur. J. For. Pathol. 20:231, 1990. (2) Y. C. Dai and K. Korhonen. Eur. J. For. Pathol. 29:273, 1999. (3) G. M. Filip and D. J. Morrison. North America. Pages 405-427 in: Heterobasidion annosum. Biology, Ecology, Impact and Control. CAB International, Wallingford, UK, 1998. (4) T. Niemelä and K. Korhonen. Taxonomy of the genus Heterobasidion. Pages 27-33 in: Heterobasidion annosum. Biology, Ecology, Impact and Control. CAB International, Wallingford, UK, 1998.

Taxus mairei (Lemee & Levl.) S.Y. Hu ex Liu is a giant evergreen tree native to Taiwan. T. mairei and the Pacific yew, T. brevifolia, produce taxol, a highly effective antitumor drug. Anthracnose was observed on cuttings and seedlings of T. mairei in nurseries and on larger plants grown in plantations in Taiwan. Circular or irregular, brown leaf spots were associated with defoliation. Stems lesions and tip dieback were also observed. Colletotrichum gloeosporioides (Penz.) Sacc. was isolated from diseased tissues, and this fungus grew well on potato dextrose agar and malt extract agar (MEA), with a growth rate of 6.3 mm per day on MEA at 32°C in the dark. Colonies were white to grayish white and became dark gray with age. Acervuli produced on leaves were 115 to 155 μm in diameter, with one or several brown-to-black setae and pale salmon conidial masses. Conidia were guttulate, straight, cylindrical, obtuse at the apex and truncate at the base, and approximately 12 to 17 × 3.5 to 6.0 μm. The disease was reproduced by spraying T. mairei seedlings with a suspension of 10 4 to 10 5 conidia per ml, and the control plants were inoculated with distilled water. Inoculated plants were kept in a transparent moist chamber with a constant humidity near 100% (1). Symptoms appeared within 7 days when the temperature was over 32°C. When the temperature was below 24°C, symptoms were delayed. The fungus was reisolated from the inoculated plants, fulfilling Koch's postulates. To our knowledge, this is the first record of anthracnose on Taxus mairei (2), and anthracnose appears to be the most important disease on this plant in Taiwan. Voucher specimens have been deposited at the Division of Forest Protection, Taiwan Forest Research Institute as TFRIFCH Herbarium specimen 137. References: (1) W. W. Hsiao et al. Taiwan J. For. Sci.17:119, 2002. (2) Y. P. Tsai, ed. List of plant diseases in Taiwan. The Plant Protection Society of the Republic of China and The Phytopathological Society of the Republic of China, 1991.

Star-cluster (Pentas lanceolata (Forssk.) Deflers) has recently become popular as a bedding plant in Taiwan. During the summer of 2000, a sudden wilt of 60-day-old plants was observed in a nursery in Tainan City (southern Taiwan). Initial symptoms included stem necrosis at the soil line and yellowing and tan discoloration of leaves. As stem necrosis progressed, infected plants wilted and died. Necrotic tissues were covered with white mycelium that differentiated into reddish brown, spherical (1 to 2 mm in diameter) sclerotia. Sclerotium rolfsii was consistently recovered from the surface of symptomatic stem sections that were disinfected for 1 min in 0.5% NaOCl and plated on potato dextrose agar amended with 100 ppm streptomycin sulfate. Pathogenicity of three isolates of S. rolfsii was confirmed by inoculating 90-day-old plants of P. lanceolata that were grown in pots. Three plants each were inoculated with a 5-mm plug of agar with mycelium or two sclerotia of the pathogen. Inoculum was placed on the soil surface against the stem of each plant. Three noninoculated plants served as controls. All plants were kept in a growth chamber at 20 to 30°C with relative humidity >85%. The pathogenicity test was repeated. Inoculated plants developed symptoms within 7 days, while control plants remained symptomless. Sclerotia developed on infected tissues and S. rolfsii was reisolated from symptomatic tissues. Although this disease has been observed on many species of plants (1), to our knowledge, this is the first report of southern blight of P. lanceolata caused by S. rolfsii in Taiwan. Reference: (1) Tsai, Y. P., ed. List of Plant Diseases in Taiwan. The Plant Protection Society of the Republic of China and The Phytopathological Society of the Republic of China. 1991.

Breadfruit (Artocarpus altilis (Parkinson) Fosberg) is an important landscape and garden tree in Taiwan. During the spring of 2002, zonate leaf spots of breadfruit were observed at a Taipei nursery in northern Taiwan. Initially, several small, brown, zonate lesions developed on leaves. As lesions enlarged, they coalesced, leading to blighting of leaves and premature defoliation. Sporophores on the host were generally hypophyllous but sometimes amphigenous, solitary, erect, easily detachable, and as much as 850 μm long. The upper portion of the sporophore is considered an individual conidium and consisted of a pyramidal head that was fusiform to ventricose and cristulate, 495 to 534 μm long and 210 to 290 μm wide at the broadest point. Branches within the pyramidal head were short and compact, and dichotomously or trichotomously branched. The conidia were hyaline, broad, septate, tapering toward an acute apex, and sometimes constricted at the basal septum. Conidiophores were 400 to 680 × 20 to 100 μm. The fungus was isolated from infected tissue and maintained on potato dextrose agar (PDA). Sclerotia were produced on PDA after 4 to 5 weeks at 20°C without light, but conidia were not observed in culture. The fungus was identified as Cristulariella moricola (Hino) Redhead based on morphological characteristics (1,2). To complete Koch's postulates, three sporophores from infected leaves or three sclerotia from cultures were placed individually on each of 10 breadfruit leaves. The plants were placed in plastic bags and incubated at 16 to 20°C. Symptoms were observed after 2 to 3 days on 100% of plants inoculated with sporophores and after 6 days on 50% of plants inoculated with sclerotia. The pathogen was reisolated from lesions on plants inoculated with sporophores and sclerotia. No symptoms were observed on the control plants. C. moricola has been known to cause a bull's eye or zonate leaf spot and defoliation on woody and annual plants, including at least 51 host species and 36 families distributed in the central and eastern United States (1). To our knowledge, this is the first report of zonate leaf spot and defoliation of breadfruit caused by C. moricola. References: (1) T. T. Chang. Bull. Taiwan For. Res. Inst. New Ser. 10 (2):235, 1995. (2) S. A. Redhead. Can. J. Bot. 53:700, 1975.

Armillaria mellea sensu stricto (Vahl:Fr.) Kummer has been found infrequently in studies conducted in northeastern North America (2) and it was not found in an earlier survey of northern Ontario (3). In a 1999 survey of Armillaria spp. conducted in central and southern Ontario, A. mellea s. str. was found at four of 110 locations surveyed, two approximately 100 km west and southwest of Ottawa, one 15 km north of Belleville, and one on the Niagara Peninsula in the Balls Falls Conservation Area. At the Ottawa area sites, A. mellea s. str. was found on red oak (Quercus rubra L.) and beech (Fagus grandifolia Ehrh.) stumps. A. ostoyae (Romagn.) Herink and A. gallica Marxmuller & Romagn. were also found on these sites. At the Belleville site, it was found on a dead co-dominant white birch (Betula papyrifera Marsh.), while at the Niagara Peninsula site it was found on a dead, suppressed beech. A. gallica was also found at these latter sites. Sites ranged from moisture regimes fresh to moist, and from sandy to silty soil from both calcareous and non-calcareous parent material. Four isolates were obtained from infected wood and rhizomorphs and identified by the polymerase chain reaction, yielding restriction fragment length polymorphism (RFLP) products of 500 and 183 base pairs. These fragment sizes are similar to findings reported in an earlier study (4). The identification was confirmed by haploid/diploid pairing. The Balls Falls Conservation Area is in close proximity to extensive fruit orchards and the presence of A. mellea is cause for concern, especially in light of its proven pathogenicity to fruit trees (1). This is the first confirmation of A. mellea s. str. in Ontario. References: (1) J. E. Adaskaveg and J. M. Ogawa. Plant Dis. 74:341-352, 1990. (2) J. T. Blodgett and J. J. Worrall. Plant Dis. 76:166-170, 1992. (3) M. T. Dumas. Can. J. For. Res. 18:872-874, 1988. (4) T. C. Harrington and B. D. Wingfield. Mycologia 87:280-288, 1995.

Pine forests are important elements of natural ecosystems in Greece. Pines are very well adapted to the ecoclimatic conditions of this country and are extensively used in plantations. While there is danger of accidental introduction of Bursaphelenchus xylophilus into Europe through timber trade, in recent years pine wilting of unknown cause has been observed in many European countries. In many cases various Bursaphelenchus spp. have been isolated from wilting conifer species (1-3). A survey for nematodes of pine in Greece was carried out from 1996 to 1998, as part of a project (FAIR 1CT 95-0083) funded by the European Commission, in which five European countries are involved. Trees chosen for sampling were either dying or recently dead. From each tree, three disks 10 cm in thickness were cut, from the lower, medium, and upper parts of the main stem. The bark was removed and Baermann-funnel-extraction for nematodes was immediately carried out for 48 h at room temperature. During the 3 years of the survey, samples from 93 pine trees from different areas of Greece were examined. Samples were obtained from the indigenous species Pinus brutia, P. halepensis, P. nigra, and P. sylvestris as well as the exotic species P. pinaster and P. radiata. Thirty-two of the samples were found infected by different species of Bursaphelenchus. B. eggersi Ruhm was isolated from P. pinaster, B. hellenicus Skarmoutsos, Braasch, and Michalopoulou from P. brutia, and B. leoni Baujard from P. brutia, P. nigra, P. pinaster, and P. radiata. B. sex-dentati Ruhm, the most abundant of all species, was recovered from P. brutia, P. halepensis, P. nigra, P. pinaster, and P. radiata, whereas B. teratospicularis Kakuliya was isolated from P. brutia and P. halepensis. Samples from P. sylvestris did not yield any Bursaphelenchus nematodes. All isolated species constitute a first record in Greece with B. hellenicus described as a new species (4). This study on the relationship between dead and dying pines and nematodes of the genus Bursaphelenchus is the first undertaken in this country. References: (1) P. Baujard. Rev. Nématol. 3:167, 1980. (2) A. Marinari Palmisano and L. Ambrogioni. Redia 77:225, 1994. (3) J. Philis and H. Braasch. Nematol. Mediterr. 24:119, 1996. (4) G. Skarmoutsos et al. Nematologica 44:623, 1998.

Mimosa, Albizia julibrissin, is an ornamental tree that thrives in Greece under difficult urban environmental conditions and is prized for its ability to create alleys. In 1991, at Kalamaria municipality, Thessaloniki, mimosa trees were found with symptoms of a Fusarium wilt disease and many trees were already dying or dead. The first symptom was a characteristic yellowing and wilting of foliage. Leaves on symptomatic trees fell prematurely and eventually the defoliated portion of crowns died. Numerous adventitious branches on the stems also developed wilt symptoms and died. When stems were cross-sectioned, a brownish discoloration in the spring wood vessels of the outer annual ring could be observed. In the more advanced stages of the disease, dark sap exudations flowed out of bark cracks. Orange-pink sporodochia with masses of conidia developed in bark cracks and lenticels. Of 1,520 trees examined for external symptoms in the autumn of 1991, 1,339 (88.2%) were apparently healthy, 96 (6.3%) had symptoms, and 85 (5.6%) were dead. In autumn 1992, the same trees were examined and the respective values were 1,276 (83.9%), 130 (8.6%), and 114 (7.5%). Wood samples from the most recent annual ring taken from 30 infected and 30 apparently healthy trees were plated on potato dextrose agar. Fusarium oxysporum was recovered from 93% of the symptomatic trees and only 7% of the asymptomatic ones. Since 1992, the disease has spread within the area where it was first found but has not been observed anywhere else in Greece. A disease of mimosa with similar symptoms was first reported by Hepting (1) in 1936 from North Carolina. The associated fungus Fusarium oxysporum f. sp. perniciosum was described by Hepting (2), who also demonstrated its pathogenicity. The disease has also been previously reported in Russia. This is the first report of mimosa wilt disease in Europe. References: (1) G. H. Hepting. Plant Dis. Rep. 20:177, 1936. (2) G. H. Hepting. USDA Circ. 535, 1939.