Search

In 2023 in Aichi Prefecture, shiso plant growth in a deep flow technique (DFT) hydroponic system was delayed from mid-March to late April with roots showing evidence of rotting. An oomycete species was isolated from the roots and identified as Phytopythium helicoides based on morphological characteristics and DNA sequence homology. Identical symptoms appeared on shiso plants after inoculating seedlings with zoospores from the strain, and the same oomycete species was reisolated from the diseased plants. This study is the first report in the world of root rot caused by P. helicoides in shiso in a DFT hydroponic system. [ABSTRACT FROM AUTHOR]

Sweet viburnum (Viburnum odoratissimum Ker-Gawl.) is a widely used ornamental plant, which has dense branches and leaves, and fast spreading and evergreen habit. In October 2022, leaf spot symptoms were observed in a hedge of sweet viburnum in Yuanshi Garden, Ningbo, China. Fungi were isolated from symptomatic leaves, and were identified using morphological characteristics and phylogenetic analyses of partial sequences of internal transcribed spacer (ITS), actin (act), and translation elongation factor 1-alpha (tef1-α), and were evaluated in pathogenicity tests. The causal agent of sweet viburnum leaf spot was identified to be Phyllosticta capitalensis. Effects of seven fungicides on P. capitalensis were assessed in vitro. Fungicide EC50s (mg L-1) against P. capitalensis were: 270.77 for 75% chlorothalonil (WP); 0.02 for 250 g L-1 azoxystrobin SC; 0.27 for 10% difenconazole WDG; 0.02 for 75% trifloxystrobin + tebuconazole WDG, 9.03 for 35% fluopyram + tebuconazole SC, 5.90 for 500 g L-1 fluazinam SC, and 89.11 for 10% prothioconazole SC. Among these, azoxystrobin SC and trifloxystrobin + tebuconazole WDG could be used for control of viburnum leaf spot. This is the first report of P. capitalensis causing leaf spot of sweet viburnum, and this study provides guidance for chemical management sweet viburnum leaf spot, and on other host plants. [ABSTRACT FROM AUTHOR]

Sunflower (Helianthus annuus) is an important oil crop, ranking behind soybean, peanut, and rapeseed in terms of planting area in China. Throughout its cultivation, sunflower is susceptible to various diseases that can significantly reduce its seed yield. Among them, Fusarium species pose a major threat to numerous crops. The accurate identification of Fusarium species responsible for specific diseases is crucial for developing effective control measures. In Inner Mongolia, sunflower disk rot (SDR) has been observed in various sunflower fields, with an average infection rate of approximately 8.50%. The infection rate can reach up to 11.67% in certain highly susceptible cultivars. Samples of diseased sunflower receptacles were collected from different locations, and Koch's postulates were employed to identify the causal agent. The results confirmed Fusarium verticillioides as the pathogen responsible for SDR. Fungicide toxicity tests were conducted, screening six fungicides for efficacy against F. verticillioides. Fludioxonil and Flutolanil were identified as the most effective, with EC50 values of 0.05 µg/mL (R = 0.9825) and 0.96 µg/mL (R = 0.9964), respectively. This is the first report of SDR caused by F. verticillioides, and it will alert sunflower researchers to include SDR in the disease list, so as to control sunflower diseases with integrated management strategies successfully. [ABSTRACT FROM AUTHOR]

Brown lesions observed on ginger rhizomes in Kochi Prefecture, Japan, appeared to be symptoms of a previously unknown disease. A filamentous fungus was isolated at high frequency from the lesions and identified as Musidium stromaticum based on its morphology and molecular analyses of ITS, LSU, TEF1-α, and RPB2. Rhizomes developed the same symptoms after inoculation with the fungus. We propose the name "brown rhizome rot" to describe this new disease of ginger. This study is the first report of M. stromaticum as a plant pathogen of ginger. [ABSTRACT FROM AUTHOR]

Pythium tracheiphilum is a narrow host range oomycete first described infecting lettuce in Italy. Subsequently, the pathogen was reported in many other countries. From 2015 to 2019, Pythium isolates were recovered from lettuce plants with symptoms of leaf rot, wilting and vascular necrosis, collected from commercial fields in different rural localities of Brasilia‐DF, Brazil. The isolates were identified as P. tracheiphilum based on morphological and molecular genetic analysis. Pathogenicity tests conducted with four P. tracheiphilum isolates confirmed that the isolates were pathogenic to detached leaves of a loose‐hearted lettuce cultivar. This is the first report of P. tracheiphilum infecting lettuces in Brazil. [ABSTRACT FROM AUTHOR]

During harvest in August 2017, wilting lettuces with crown rot were observed in Kagawa Prefecture, Japan. Fungi with aseptate hyphae were isolated from the rotted crowns. Based on phylogenetic analyses, morphological characteristics, and minimum, maximum, and optimum temperatures for hyphal growth, the isolate was identified as Phytophthora crassamura. This is the first report of lettuce crown rot caused by P. crassamura in Japan. We propose the name crown rot of lettuce (retasu eki-byo in Japanese) for this lettuce disease. [ABSTRACT FROM AUTHOR]

In February 2023 in Japan, seedlings of wax gourd [Benincasa hispida (Thunb.) Cogn.] in seedling boxes developed water-soaked rot on hypocotyls typical of damping off and eventually died. A Pythium sp. was isolated from the hypocotyls and was identified as Pythium aphanidermatum based on morphological characteristics and DNA sequence data. The same symptoms developed after seedlings were inoculated with the isolated fungus, and the same fungus was reisolated from the seedlings. This is the first report of damping off in wax gourd seedlings caused by P. aphanidermatum in seedling boxes in Japan. [ABSTRACT FROM AUTHOR]

Sunflower (Helianthus annuus) is an important oil crop, ranking behind soybean, peanut, and rapeseed in terms of planting area in China. Throughout its cultivation, sunflower is susceptible to various diseases that can significantly reduce its seed yield. Among them, Fusarium species pose a major threat to numerous crops. The accurate identification of Fusarium species responsible for specific diseases is crucial for developing effective control measures. In Inner Mongolia, sunflower disk rot (SDR) has been observed in various sunflower fields, with an average infection rate of approximately 8.50%. The infection rate can reach up to 11.67% in certain highly susceptible cultivars. Samples of diseased sunflower receptacles were collected from different locations, and Koch’s postulates were employed to identify the causal agent. The results confirmed Fusarium verticillioides as the pathogen responsible for SDR. Fungicide toxicity tests were conducted, screening six fungicides for efficacy against F. verticillioides. Fludioxonil and Flutolanil were identified as the most effective, with EC50 values of 0.05 µg/mL (R = 0.9825) and 0.96 µg/mL (R = 0.9964), respectively. This is the first report of SDR caused by F. verticillioides, and it will alert sunflower researchers to include SDR in the disease list, so as to control sunflower diseases with integrated management strategies successfully.

Viburnum odoratissimum Ker-Gawl is native to Asia and is usually used as a garden ornamental. In September 2022, a leaf blotch on V. odoratissimum was observed in Nanjing, Jiangsu, China. The disease causes the leaves of the plants to curl and dry up and defoliate early. It not only seriously affects the growth of the plants but also greatly reduces the ornamental value. The pathogenic fungus was isolated from the diseased leaves, and the fungus was identified to be Colletotrichum siamense based on morphological features and multilocus phylogenetic analyses of the internal transcribed spacer (ITS) region, actin (ACT), calmodulin (CAL), beta-tubulin 2 (TUB2), chitin synthase (CHS-1), Apn2-Mat1-2 intergenic spacer and partial mating type (ApMat), and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) genes. Pathogenicity tests were performed by inoculating healthy leaves with conidia. C. siamense can grow at 15–35 °C, with an optimal growth temperature at 25–30 °C. The results of sensitivity to nine fungicides showed that C. siamense was the most sensitive to prochloraz in the concentration range of 0.01 μg/mL to 100 μg/mL. Therefore, spraying prochloraz before the optimum growth temperature of pathogenic fungus can achieve effective control. It provided useful information for future studies on the prevention and treatment strategies of C. siamense. This is the first report of leaf blotch caused by C. siamense on V. odoratissimum in China and worldwide. [ABSTRACT FROM AUTHOR]

Celtis julianae Schneid. is widely planted as a versatile tree species with ecological and economic significance. In September 2022, a leaf blotch disease of C. julianae was observed in Nanjing, Jiangsu, China, with an infection incidence of 63%. The disease led to severe early defoliation, significantly affecting the ornamental and ecological value of the host tree. The accurate identification of pathogens is imperative to conducting further research and advancing disease control. Koch's postulates confirmed that the fungal isolates (B1–B9) were pathogenic to C. julianae. The morphology of the characteristics of the pathogen matched those of Alternaria spp. The internal transcribed spacer region (ITS), large subunit (LSU) and small subunit (SSU) regions of rRNA, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), Alternaria major allergen gene (Alt a 1), RNA polymerase second largest subunit (RPB2), and portions of translation elongation factor 1-alpha (TEF1-α) genes were sequenced. Based on multi-locus phylogenetic analyses and morphology, the pathogenic fungi were identified as Alternaria arborescens and A. italica. The findings provided useful information for disease management and enhanced the understanding of Alternaria species diversity in China. This is the first report of A. arborescens and A. italica causing leaf blotch of C. julianae in China and worldwide. [ABSTRACT FROM AUTHOR]

Astragalus strictus (Fabaceae) is one of the major locoweeds commonly found in Tibet, China. In 2021 and 2022, the occurrence of powdery mildew on A. strictus leaves was investigated in Tibet with approximately 50‒70% disease incidence and 26.9‒37.5% disease severity. The typical symptoms included white powdery mildew colonies and dark chasmothecia on the host leaves. To identify the causal agent, fresh leaves covered with powdery mildew were collected and identified by morphology and molecular analyses. Phylogenetic analyses of the internal transcribed spacer (ITS) region and the 28 S (large subunit) rDNA showed that our collection was clustered with Erysiphe astragali. The morphology of our collection was appendages equatorially and flexuous, asci 4–8 per chasmothecium, ovoid to subglobose and ascospores 4 per ascus, ovoid or ellipsoid. A pathogenicity test on plants by pressing naturally infected leaves onto healthy leaves confirmed that the tested fungus was pathogenic. Therefore, E. astragali was identified as the causative agent of this disease. To our knowledge, this is the first report of E. astragali associated with powdery mildew on A. strictus in China. [ABSTRACT FROM AUTHOR]

Cryptomeria japonica D. Don is a coniferous tree species widely grown in southern China for its high ornamental value. Recently, during disease surveys in China, a symptom of dieback occurred on C. japonica in Nanjing, Jiangsu Province, China. A total of 130 trees were surveyed and more than 90% showed the same symptom. The crowns of affected trees were brown when viewing from a distance, and the bark showed no difference from the healthy ones. In this study, 157 isolates were isolated from the 3 affected plants of C. japonica, and based on the living culture on PDA, the fungal isolates were preliminarily divided into 6 groups. Thirteen representative isolates were selected for the pathogenicity test, and seven of them showed obvious pathogenicity on C. japonica, causing stem basal canker. These isolates were identified based on comparisons of the DNA sequences of the internal transcribed spacer regions (ITS), partial translation elongation factor 1-alpha (tef1), β-tubulin (tub2), and DNA-directed RNA polymerase II subunit (rpb2) and combined with their morphological characteristics. Results showed that these seven isolates belong to two taxa in Neofusicoccum, including a species new to science. The new species, Neofusicoccum cryptomeriae, was hereby described and illustrated. The other species was N. parvum. Both species were pathogens of stem basal canker of Cryptomeria japonica. [ABSTRACT FROM AUTHOR]

A dieback was observed on three-year-old pot-grown plants of Cycas revoluta in Sicily (Italy). Symptoms, including stunting, yellowing and blight of the leaf crown, root rot and internal browning and decay of the basal stem, closely resembled the Phytophthora root and crown rot syndrome, common in other ornamentals. Isolations from rotten stem and roots, using a selective medium, and from rhizosphere soil of symptomatic plants, using leaf baiting, yielded three Phytophthora species, P. multivora, P. nicotianae and P. pseudocryptogea, were obtained. Isolates were identified by both morphological characters and DNA barcoding analysis, using three gene regions: ITS, β-tub and COI. Phytophthora pseudocryptogea was the sole species isolated directly from the stem and roots. The pathogenicity of the isolates of the three Phytophthora species was tested on one-year-old potted plants of C. revoluta, using both stem inoculation by wounding, and root inoculation through infested soil. Phytophthora pseudocryptogea was the most virulent and, like P. nicotianae, reproduced all the symptoms of natural infections, while P. multivora was the least virulent and induced solely very mild symptoms. Phytophthora pseudocryptogea was identified as the causal agent of the decline of C. revoluta, as it was re-isolated from both the roots and stems of artificially infected symptomatic plants, thus fulfilling Koch's postulates. [ABSTRACT FROM AUTHOR]

From June through October 2020, symptoms of a branch blight disease were observed on Physocarpus amurensis plants in Harbin City, Heilongjiang Province, China. Leaves on infected branches were chlorotic, with many raised, grey spots forming on the epidermis of diseased branches. Diseased twigs formed semi‐buried, small, spherical pycnidia, which were initially light brown and later turned dark. The pathogen was isolated and its pathogenicity was verified with Koch's postulates. Based on morphological characteristics and DNA sequence data the pathogen was identified as Aplosporella longipes. This is the first report of A. longipes in China and the first report of it causing branch blight disease of P. amurensis. [ABSTRACT FROM AUTHOR]

Typical bacterial symptoms, water-soaking brown and black leaf spots with yellow halo, were observed on watermelon seedlings in nursery and field of Gyeongnam and Jeonnam provinces. Bacterial isolates from the lesion showed strong pathogenicity on watermelon and zucchini. One of them was rod-shaped with 4 polar flagella by observation of transmission electron microscopy. They belonged to LOPAT group 1. The phylogenical trees with nucleotide sequences of 16S rRNA and multi-locus sequencing typing with the 4 house-keeping genes (gapA, gltA, gyrB, and rpoD) of the isolates showed they were highly homologous to Pseudomonas syringae pv. syringae and grouped together with them, indicating that they were appeared as P. syringae genomospecies group 1. Morphological, physiological, and genetical characteristics of the isolates suggested they are P. syringae pv. syringae. We believe this is the first report that P. syringae pv. syringae caused leaf spot disease on watermelon in the Republic of Korea.

Viburnum odoratissimum Ker-Gawl is native to Asia and is usually used as a garden ornamental. In September 2022, a leaf blotch on V. odoratissimum was observed in Nanjing, Jiangsu, China. The disease causes the leaves of the plants to curl and dry up and defoliate early. It not only seriously affects the growth of the plants but also greatly reduces the ornamental value. The pathogenic fungus was isolated from the diseased leaves, and the fungus was identified to be Colletotrichum siamense based on morphological features and multilocus phylogenetic analyses of the internal transcribed spacer (ITS) region, actin (ACT), calmodulin (CAL), beta-tubulin 2 (TUB2), chitin synthase (CHS-1), Apn2-Mat1-2 intergenic spacer and partial mating type (ApMat), and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) genes. Pathogenicity tests were performed by inoculating healthy leaves with conidia. C. siamense can grow at 15–35 °C, with an optimal growth temperature at 25–30 °C. The results of sensitivity to nine fungicides showed that C. siamense was the most sensitive to prochloraz in the concentration range of 0.01 μg/mL to 100 μg/mL. Therefore, spraying prochloraz before the optimum growth temperature of pathogenic fungus can achieve effective control. It provided useful information for future studies on the prevention and treatment strategies of C. siamense. This is the first report of leaf blotch caused by C. siamense on V. odoratissimum in China and worldwide.

Celtis julianae Schneid. is widely planted as a versatile tree species with ecological and economic significance. In September 2022, a leaf blotch disease of C. julianae was observed in Nanjing, Jiangsu, China, with an infection incidence of 63%. The disease led to severe early defoliation, significantly affecting the ornamental and ecological value of the host tree. The accurate identification of pathogens is imperative to conducting further research and advancing disease control. Koch’s postulates confirmed that the fungal isolates (B1–B9) were pathogenic to C. julianae. The morphology of the characteristics of the pathogen matched those of Alternaria spp. The internal transcribed spacer region (ITS), large subunit (LSU) and small subunit (SSU) regions of rRNA, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), Alternaria major allergen gene (Alt a 1), RNA polymerase second largest subunit (RPB2), and portions of translation elongation factor 1-alpha (TEF1-α) genes were sequenced. Based on multi-locus phylogenetic analyses and morphology, the pathogenic fungi were identified as Alternaria arborescens and A. italica. The findings provided useful information for disease management and enhanced the understanding of Alternaria species diversity in China. This is the first report of A. arborescens and A. italica causing leaf blotch of C. julianae in China and worldwide.

The fungal disease of Cordyceps militaris has become the primary disease during the cultivation of C. militaris. However, some of the causal organism remains unclear. During our investigation in 2020–2022, three fungal strains were isolated from both the mycelium and fruiting bodies of C. militaris in mushroom farms located in Changchun. The observed disease incidence was approximately 20%. White villous mycelium on the surface of hyphae or fruiting bodies of C. militaris , is one of the main features of the disease, which can cause slow growth of mycelium, delayed primordia differentiation, and growth failure. Finally, the white cotton flocculent mycelium covered the surface of the medium, and the C. militaris stopped differentiating and failed to produce the primordium, ultimately leading to the stunted growth and lodging of the fruiting body. The objective of this study was to identify the pathogen based on Koch's Postulates, thereby confirming its pathogenicity and characterizing it through morphological and molecular features. The phylogenetic analyses showed that they belong to the Trichoderma gamsii. This study presented the first evidence of T. gamsii caused fungal disease in C. militaris , providing a theoretical basis for the prevention and control measures. • The outbreak of fungal diseases in Cordyceps militaris cultivation poses a significant threat to production and quality. • The disease incidence was approximately 20%, which led to significant yield losses. • The pathogen responsible for white mildew disease was identified as Trichoderma gamsii. • This is the first report of Trichoderma gamsii causing white mildew disease in Cordyceps militaris in China. • The results facilitate the development of strategies for white mildew disease of Cordyceps militaris. [ABSTRACT FROM AUTHOR]

Severe stunting and root rot were observed on alpine delphinium plants (Delphinium elatum) from Aomori Prefecture, Japan, in 2010 and 2011. A Phytophthora isolate from the diseased crown was identified as Phytophthora sp. kelmania based on morphological characteristics and DNA sequence data. Inoculation of alpine delphinium plants with the isolate produced a similar root rot. Pathogenicity of the isolate on four species of plants that are known hosts for P. sp. kelmania was confirmed. We propose the name "Phytophthora rot" (eki-byo in Japanese) for the present new disease on alpine delphinium. [ABSTRACT FROM AUTHOR]

A dieback was observed on three-year-old pot-grown plants of Cycas revoluta in Sicily (Italy). Symptoms, including stunting, yellowing and blight of the leaf crown, root rot and internal browning and decay of the basal stem, closely resembled the Phytophthora root and crown rot syndrome, common in other ornamentals. Isolations from rotten stem and roots, using a selective medium, and from rhizosphere soil of symptomatic plants, using leaf baiting, yielded three Phytophthora species, P. multivora, P. nicotianae and P. pseudocryptogea, were obtained. Isolates were identified by both morphological characters and DNA barcoding analysis, using three gene regions: ITS, β-tub and COI. Phytophthora pseudocryptogea was the sole species isolated directly from the stem and roots. The pathogenicity of the isolates of the three Phytophthora species was tested on one-year-old potted plants of C. revoluta, using both stem inoculation by wounding, and root inoculation through infested soil. Phytophthora pseudocryptogea was the most virulent and, like P. nicotianae, reproduced all the symptoms of natural infections, while P. multivora was the least virulent and induced solely very mild symptoms. Phytophthora pseudocryptogea was identified as the causal agent of the decline of C. revoluta, as it was re-isolated from both the roots and stems of artificially infected symptomatic plants, thus fulfilling Koch’s postulates.

Cryptomeria japonica D. Don is a coniferous tree species widely grown in southern China for its high ornamental value. Recently, during disease surveys in China, a symptom of dieback occurred on C. japonica in Nanjing, Jiangsu Province, China. A total of 130 trees were surveyed and more than 90% showed the same symptom. The crowns of affected trees were brown when viewing from a distance, and the bark showed no difference from the healthy ones. In this study, 157 isolates were isolated from the 3 affected plants of C. japonica, and based on the living culture on PDA, the fungal isolates were preliminarily divided into 6 groups. Thirteen representative isolates were selected for the pathogenicity test, and seven of them showed obvious pathogenicity on C. japonica, causing stem basal canker. These isolates were identified based on comparisons of the DNA sequences of the internal transcribed spacer regions (ITS), partial translation elongation factor 1-alpha (tef1), β-tubulin (tub2), and DNA-directed RNA polymerase II subunit (rpb2) and combined with their morphological characteristics. Results showed that these seven isolates belong to two taxa in Neofusicoccum, including a species new to science. The new species, Neofusicoccum cryptomeriae, was hereby described and illustrated. The other species was N. parvum. Both species were pathogens of stem basal canker of Cryptomeria japonica.

Leaf spot of Hosta ventricosa is a new disease in China. This disease seriously affects the ornamental value and greening function of H. ventricosa. Identification of the causal agent can prevent and control leaf spot in H. ventricosa and promote the healthy development of the H. ventricosa industry. Known incidents of leaf spot of H. ventricosa occurred in three places, and samples were collected. After the fungus were isolated, its pathogenicity was tested according to Koch's postulates. Isolates ZE-1b and ZE-2b were identified as Fusarium oxysporum based on morphological features and multigene phylogenetic analyses of calmodulin (CMDA), RNA polymerase II subunit A (RPB1), RNA polymerase II second largest subunit (RPB2) and translation elongation factor 1-alpha (TEF1). These results provide a theoretical basis for the control of this disease of H. ventricosa. [ABSTRACT FROM AUTHOR]

In June 2017, deer-horn-like galls covered with a whitish, powdery fungal layer were found on the trunks of Cinnamomum pseudopedunculatum (Lauraceae) in Hahajima, Bonin Islands, Japan. The galls were similar to those of horn gall disease of Ci. tenuifolium caused by Laurobasidium hachijoense (Laurobasidiaceae, Exobasidiales) on Hachijo Island, approximately 700 km north of Hahajima. Based on morphological observation and molecular analyses of ITS and LSU regions, the fungus isolated from the surface of the galls was identified as L. hachijoense. This is the first report of the horn gall disease of Ci. pseudopedunculatum. [ABSTRACT FROM AUTHOR]

Morels (Morchella spp.) are commercially important edible mushrooms with high nutritional and medicinal value. There are more than twenty provinces in China that cultivate Morel mushrooms. As of 2023, white mold disease on cultivated Morchella sextelata has become a disease of concern in Sichuan Province, China, with a disease incidence of 12.13%. The ascocarp infected with white mold disease appears covered with a dense white mycelia of a foreign fungus and disintegrates soon after. However, the causal agent is not yet known. Therefore, this study aims to confirm both the causal pathogen by using Koch's postulates and to further establish, at the species level, the identity of this organism via morphological and molecular methods. The pathogens were later identified as Hypomyces rosellus and Hypomyces aurantius. Healthy ascocarps were inoculated with H. rosellus and H. aurantius , which produced the initial disease symptoms with white mold appearing at the inoculation sites, and H. aurantius showed stronger pathogenicity than H. rosellus ; the same pathogens were then isolated again from diseased ascocarp. To our knowledge, this is the first report of the ascocarp cobweb disease of cultivated M. sextelata caused by H. rosellus in China. Our work may be beneficial, especially for designing control measures for ascocarp cobweb disease in the commercial cultivation of M. sextelata. • In this paper, we checked the pathogenicity of Hypomyces rosellus and Hypomyces aurantius in same time. And found that Hypomyces rosellus exhibits stronger pathogenicity towards Morchella sextelata compared to Hypomyces aurantius. • We illustrated some more clearer photographs to describe the morphological characterization of Hypomyces rosellus and Hypomyces aurantius. [ABSTRACT FROM AUTHOR]

In September 2019, small black spots were observed on mature calyces of Cape gooseberry (Physalis pruinosa L.) in a commercial greenhouse in Japan, which markedly decreased their commercial value. A fungus was isolated from a mature calyx and identified as Cladosporium tenuissimum based on morphological examination and molecular analysis using internal transcribed spacers (ITSs). Inoculation of mature calyces with the isolated fungus resulted in the same symptoms, and the fungus was reisolated from the diseased calyx. This is the first report on sooty spot on mature calyces of Cape gooseberry. [ABSTRACT FROM AUTHOR]

Pink coloration of barley seeds has caused quality loss since 2015 in some areas where barley is grown in Japan. A bacterium, isolated frequently from the affected seeds and identified as Erwinia persicina, was demonstrated to induce the coloration. Barley was judged to be a new host for E. persicina, and this new disease was named pink seed of barley. [ABSTRACT FROM AUTHOR]

Leaf spot of soapberry, Sapindus mukorossi is a disease new to China. The disease significantly reduces not only the plant's ornamental value but also its medicinal properties. Identification of pathogens timely assists preventing and controlling this disease. In July 2019, foliage of soapberry on the campus of Nanjing Forestry University, China, was infected by the disease, and the disease incidence was 96%. Symptomatic leaves were collected from three infected trees. After isolating the fungus, its pathogenicity was tested to satisfy Koch's postulates, and the culture was identified based on its morphological features and multi-gene phylogenetic analyses. Isolates WHZ3 and YB1 from the diseased leaves were identified as Diaporthe biconispora, and the identification was confirmed using morphological features and multi-gene phylogenetic analyses derived from an internal transcribed spacer (ITS), elongation factor 1-alpha (EF1-α), beta-tubulin (β-tub), histone H3 (HIS), and calmodulin (CAL). Koch's postulates proved the fungus to be a pathogen on soapberry. Diaporthe biconispora was previously reported as an endophyte in plants of the Citrus group, but was shown to be pathogenic to soapberry causing leaf spots. [ABSTRACT FROM AUTHOR]

Mulberry (Morus spp.), represents a set of plants grown in Brazil for production of fruits, leaves for feeding silkworms and ruminant animals, and for landscape. In 2017 mulberry leaves with symptoms of spots were collected in Santa Catarina (SC) state and in the Distrito Federal (DF). Three fungal isolates obtained from M. nigra in DF and one isolate obtained from M. alba in SC state were characterized by both molecular and morphological tools. Phylogenetic analysis showed that all isolates were grouped with isolates belonging to the species Neophloeospora maculans. All isolates were pathogenic on leaves of M. nigra seedlings under greenhouse conditions and were re-isolated in pure culture, completing the Koch's postulates. One isolate was morphologically characterized, and it showed colonies with slow growth, grayish-white color and conidia hyaline, septated, filiform, straight or curved, measuring 56 (25–70) × 4.5 (2.5–5) that confirms the molecular identification. This work reposts M. nigra as a new host of N. maculans in Brazil, as well as expands the geographic distribution of this fungus in the country. This information is potentially relevant for establishing effective disease management strategies. [ABSTRACT FROM AUTHOR]

A new disease of strawberry (Fragaria ananassa Duch.) was discovered in the Lianqiao strawberry planting base in Shaodong County, in Hunan Province, China. In the early disease stage, leaves showed small black spots surrounded by yellow halos, while in the late stage, a white fluffy layer of mold appeared. Fruits were covered with a white layer of mold. The symptoms were observed using in vitro inoculation experiments. After the spray-inoculation of stabbed leaves, small black spots surrounded by yellow halos occurred on leaves, with no clear boundary between diseased and healthy areas. In the late stage, disease spots gradually expanded and a white fluffy layer of mold formed under humid conditions. Unstabbed leaves had almost no disease occurrence after spray-inoculation. After the spray-inoculation of stabbed fruits, by the late stage, a dense white layer of mold formed. According to Koch's postulates, the isolated strain was verified as a pathogen. The pathogenic strain, designated SDLQ16, was isolated from diseased fruit by dilution method and tentatively identified as G. candidum based on the culture characteristics, morphologies, physio-biochemical analysis, and phylogenetic analysis of the rDNA-ITS sequence. The fungus was able to grow on different culture mediums, with a broad range of nutrition. The colonies on PDA medium were raised and pale white, with a neat edge and visible hyphae. The hyphae were friable but the spores were developing. Basal hyphae rapidly grew close to the medium to 3.2-4.2 µm in diameter, with septa and forked branches at acute angles. The solitary or beaded spores with smooth surfaces were 3.5-7.5 µm in length and 3.5-4.5 µm in width. This strain was able to gelatin liquefaction, proteolysis, grease, peptonised milk, urea, and so on. The pathogenicity on strawberry from strong to weak was: fruit > leaf > stem. A BLAST algorithm was used to query SDLQ16's rDNA-ITS sequence (cloned and deposited as GenBank number KU373122) against the NCBI database, and it was located in the Acinetobacter sp. branch of a phylogenetic tree. SDLQ16 was most closely related to Geotrichum candidum ATCC34614 (GQ4580314.1), with a sequence similarity of 99%.

Cercospora blight caused by Cercospora asparagi routinely developed on asparagus in certain plastic hoop houses in Hiroshima Prefecture in western Japan every July to November. Stemphylium lycopersici was repeatedly isolated with C. asparagi from the blighted leaves in September 2016 and shown to be another causal agent of the blighting and added as another pathogen causing Stemphylium leaf spot of asparagus. [ABSTRACT FROM AUTHOR]

Blast disease is a notorious fungal disease leading to dramatic yield losses on major food crops such as rice and wheat. The causal agent, Pyricularia oryme, encompasses different lineages, each having a different host range. Host shifts are suspected to have occurred in this species fronl Setaria spp. to rice and from Loliwn spp. to wheat, The emergence of blast disease on maize in Iran was observed for the first time in the north of the country in 2012. We later identified blast disease in two additional regions Iran: Gilan in 2013 and Golestan in 2016. Epidemics on the weed bat-nyard grass (Echinochloa spp.) were also observed in the same maize fields. Here, we showed that P orvzae is the causal agent of this disease on both hosts. Pathogenicity assays in the greenhouse revealed that strains from maize can infect barnyard grass and conversely. However, genotyping with simple sequence repeat markers and comparative genomics showed that strains causing field epidemics on nmize and on bat-nyard grass are Blast disease is a notorious fungal disease leading to dramatic yield losses on major food crops such as rice and wheat. The causal agent, Pyricularia oryme, encompasses different lineages, each having a different host range. Host shifts are suspected to have occurred in this species fronl Setaria spp. to rice and from Loliwn spp. to wheat, The emergence of blast disease on maize in Iran was observed for the first time in the north of the country in 2012. We later identified blast disease in two additional regions Iran: Gilan in 2013 and Golestan in 2016. Epidemics on the weed bat-nyard grass (Echinochloa spp.) were also observed in the same maize fields. Here, we showed that P orvzae is the causal agent of this disease on both hosts. Pathogenicity assays in the greenhouse revealed that strains from maize can infect barnyard grass and conversely. However, genotyping with simple sequence repeat markers and comparative genomics showed that strains causing field epidemics on nmize and on bat-nyard grass are Blast disease is a notorious fungal disease leading to dramatic yield losses on major food crops such as rice and wheat. The causal agent, Pyricularia oryme, encompasses different lineages, each having a different host range. Host shifts are suspected to have occurred in this species fronl Setaria spp. to rice and from Loliwn spp. to wheat, The emergence of blast disease on maize in Iran was observed for the first time in the north of the country in 2012. We later identified blast disease in two additional regions Iran: Gilan in 2013 and Golestan in 2016. Epidemics on the weed bat-nyard grass (Echinochloa spp.) were also observed in the same maize fields. Here, we showed that P orvzae is the causal agent of this disease on both hosts. Pathogenicity assays in the greenhouse revealed that strains from maize can infect barnyard grass and conversely. However, genotyping with simple sequence repeat markers and comparative genomics showed that strains causing field epidemics on nmize and on bat-nyard grass are different, although they belong to the same previously undescribed clade of P. oryme. Phylogenetic analyses including these strains and a maize strain collected in Gabon in 1985 revealed two independent host-range expansion events from barnyard grass to maize. Comparative genomics between maize and barnyard grass strains revealed the presence or absence of five candidate genes associated with host specificity on maize. with the deletion of a small genomic region possibly responsible for adaptation to maize. This recent emergence of P on, zae on maize provides a case study to understand host range expansion. Epidemics on maize raise concerns about potential yield losses on this crop in Iran and potential geographic expansion of the disease. [ABSTRACT FROM AUTHOR]

A stem rot disease appeared on hydrangea plants in Tochigi Prefecture, Japan. Four Phytophthora-like isolates were obtained, and a representative isolate was selected for analysis. Hydrangea plants inoculated with the isolate developed similar symptoms. Molecular phylogenetic analyses using the rDNA ITS region and cox1, EF1-α, and β-tubulin genes indicated that the isolate was Phytophthora hedraiandra. The sporangia were papillate, laterally sessile, and caducous. Antheridia were paragynous or amphygynous, and laterally sessile, and the oospores were aplerotic. Based on these characteristics, the isolate was identified as P. hedraiandra. We suggest naming this hydrangea disease "Ajisai kukieki byo". [ABSTRACT FROM AUTHOR]

Copyright of Bioscience Journal is the property of Bioscience Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Fusarium oxysporum f. sp. lycopersici (FOL) races 1 and 2 were, up to recent years, the only pathogenic Fusaria associated with tomatoes (Solanum lycopersicum L.) in Brazil. However, recent outbreaks of F. oxysporum isolates with the ability to breakdown the I–2-mediated resistance prompted us to conduct nationwide surveys of the pathogens associated with vascular wilt of tomatoes. During these surveys, eight atypical F. oxysporum isolates (collected across five tomato–producing Brazilian states) displayed a peculiar ability of infecting accessions carrying the I–3 and I–7 genes (controlling resistance to FOL race 3 isolates). These observations suggested the involvement of either a new FOL race or of F. oxysporum f. sp. radicis-lycopersici (FORL) isolates. Koch's postulates were fulfilled for these eight atypical isolates via root dipping inoculation (106 conidia mL− 1) of seedlings from two tomato cultivars 'Ponderosa' and 'Dominador'. All eight isolates induced crown-rot symptoms only in 'Ponderosa', but not in 'Dominador' (which is resistant to FORL). To confirm the FORL identity, PCR assays were done using a set of race-specific and forma specialis-specific primers. A single amplicon of ≈ 947 bp was observed with the primer pair Sprl only with DNA template obtained from standard FORL isolates and from the eight atypical isolates, confirming the first detection of this forma specialis in Brazil. The geographical distribution of FORL isolates across major tomato–producing areas may require the incorporation of resistant factors into adapted cultivars. [ABSTRACT FROM AUTHOR]

In November 2015, leaf blight on Schima mertensiana was found in Chichijima, Bonin Islands, Tokyo, Japan. The causal fungus was isolated from the leaf symptoms and identified as Colletotrichum sp. based on morphological examination and molecular analysis using ITS, ACT, CHS-1, CAL, and TUB2 sequences. Leaf blight similar to the natural symptoms developed after leaves were inoculated with the isolate. This is the first report of leaf blight on S. mertensiana caused by Colletotrichum species in Japan, and anthracnose, "tanso-byo" in Japanese, is proposed as the disease name. [ABSTRACT FROM AUTHOR]

In September 2015, stem blight was found on Joseph's coat amaranth (Amaranthus tricolor) in Kanagawa, Japan. A fungus was isolated from brown spots on the stems and leaves. After our inoculation tests using the isolated fungus, the same symptoms were observed in the field. The pathogen was identified as Diaporthe amaranthophila based on morphological and molecular analyses. This is the first report of D. amaranthophila as a pathogen of stem blight on Joseph's coat amaranth in Japan. [ABSTRACT FROM AUTHOR]

The rubber tree (Hevea brasiliensis) is the only resource for commercial natural rubber production and thus has economic importance in Southeast Asia. A spot disease on the leaves of a rubber tree was first discovered in 2017 in Hainan, China. In this study, the fungal isolate MA1 from the infected tissues was determined to be a pathogen of the spot disease by satisfying Koch's postulates. The isolate MA1 was identified as Bipolaris bicolor based on the morphological characteristics and multigene phylogenetic analysis. Among fungicides, prochloraz, iprodione and pyraclostrobin significantly inhibited hyphal growth of B. bicolor under in vitro conditions. This study constitutes the first report on the association of B. bicolor with leaf spot disease of rubber trees worldwide. [ABSTRACT FROM AUTHOR]

Bambusa multiplex has been broadly cultivated in China and has significant economical, ecological and ornamental importance. A canker on the culm of B. multiplex was first time discovered in 2015 in Shanghai, China. In this study, the fungal isolate XSZ‐1 isolated from the infected tissues was determined to be a pathogen of canker on the culm of B. multiplex by fulfilling Koch's postulates. The fungal pathogen was identified as Fusarium incarnatum based on the morphological characteristics and phylogenetic analyses with the sequences of ITS, TEF‐1α and RPB2. To our knowledge, this is the first report of a canker on the culm of B. multiplex caused by F. incarnatum worldwide. [ABSTRACT FROM AUTHOR]

Cayratia japonica is widely used as a traditional medicine in China. Recently, it has been affected by anthracnose disease, which influences its growth and medicinal value. This disease has occurred extensively in Nanchang, Jiangxi, China, but the causal agent of anthracnose on this host is unknown. Colletotrichum -isolates were obtained from the diseased leaves. On PDA, the fungus produced white, mycelium on the surface and light gray at the bottom with dark-green pigmentation around the inoculation point. The fungal isolate was classified as Colletotrichum siamense based on morphological features and multi-genes phylogenetic analyses. Pathogenicity tests were conducted by inoculating with conidial suspensions on leaves, and Koch's postulates were confirmed. This is the first report that C. siamense causes anthracnose on C. japonica in China. • New Cayrati japonica disease was reported. • New host of Colletotrichum siamense was verified. [ABSTRACT FROM AUTHOR]

Fusarium asiaticum was repeatedly isolated from blighted spikes of durum wheat with head blight-like symptoms in our experimental fields in Fukuyama, Hiroshima Prefecture in western Japan, then demonstrated to be pathogenic to the crop. F. asiaticum was not previously reported as causing head blight on durum wheat, so it has been added to the pathogens causing this disease. [ABSTRACT FROM AUTHOR]

Jasminum mesnyi Hance is an important medicinal and ornamental plant. This species is native to South Central China and Vietnam and grows primarily in the subtropical biomes. In June 2022, 17 Colletotrichum strains were isolated from leaf tip blight on foliage of J. mesnyi in Nanjing, Jiangsu, China. Based on morphological characteristics and multilocus phylogenetic analyses of six genomic loci (ITS, CAL , ACT , TUB2 , CHS-1 , and GAPDH ), a new species, namely, C. nanjingense , and a known species, namely, C. gloeosporioides s.s., were described and reported. Pathogenicity tests revealed that both species were pathogens causing leaf tip blight on J. mesnyi . The results provided necessary information for disease control and enhanced our understanding of the diversity of Colletotrichum species in China., Competing Interests: The author(s) declare no conflict of interest.