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Summary A new species of cyst-forming nematode, Heterodera amaranthusiae n. sp., is described and illustrated from the weed, Amaranthus retroflexus, in a potato field in Yunnan Province, China. It is characterised by having canary to russet-brown and asymmetric lemon-shaped cyst, distinct neck, bifenestrate vulval cone, relatively short vulval slit of 29 (28-32) μm, bullae absent and underbridge absent or weak if present. Second-stage juveniles are characterised by a well-developed stylet of 23 (22-25) μm with robust shaft and basal knobs concave anteriorly, tail conoid, 51 (48-58) μm long and hyaline region comprising 48 (41-53)% of its length. Morphologically and morphometrically it most resembles H. vallicola in the Humuli group. The ITS, 28S and COI gene sequences of H. amaranthusiae n. sp. clearly differentiate it from other Heterodera species. For diagnostic purposes, restriction enzyme analysis of the ITS region and three restriction enzymes, AluI, BsuRI (HaeIII) and CfoI (HhaI), were selected, clearly distinguishing H. amaranthusiae n. sp. from representative species in the Humuli group. Phylogenetic relationships with other species of the genus, inferred from two ribosomal regions and the cytochrome oxidase c subunit 1 region, based on Bayesian analysis, consistently showed that H. amaranthusiae n. sp. clustered with high support with other Humuli group species but with separate species status. more...

Globodera infestation was evaluated in soils of private farm plots in Chernihiv and Kyiv regions of Ukraine in 2017–2018. Soil samples were taken at 88 farms, 15.02 ha in total, in 11 settlements of 6 districts. The nematode abundance in the examined areas was graded as follows: less than 1000 eggs + larvae/100 cm3 — low rate of infestation; 1000–5000 eggs + larvae/100 cm3 — average rate; more than 5000 eggs + larvae/100 cm3 — high rate. 85.4 % of study area is infested with the golden potato cyst nematode. The mean abundance of pest was 3331 (15–23,237) eggs+larvae/100 cm3: including 8730 (91–21,486) eggs+larvae/100 cm3 in Kyiv Region and 1829.6 (15–23,237) eggs+larvae/100 cm3 in Chernihiv Region. The highest number of assessed plots per district (29) was in Koryukivsky District, and the mean abundance of G. rostochiensis (Rо-1) was 1549 (20–15,757) eggs + larvae/100 cm3e+l/100cm3. We also analyzed the results of golden nematode monitoring conducted by the State Service of Ukraine for food safety and consumer protection in 2018. According to those, the golden nematode is found in 18 regions of Ukraine. In most of those (14 regions), the pest infests rather small areas, less than 500 ha. Globodera is not recorded in the other 7 regions of Ukraine and Autonomous Republic of Crimea for now. more...

Cactodera torreyanae Cid del Prado Vera & Subbotin, 2014 cysts were discovered during a Pale Potato Cyst Nematode (PCN) survey conducted by Minnesota Department of Agriculture as part of the Animal and Plant Health Inspection Service (APHIS) efforts to survey states for the presence of PCN. The soil samples were collected from a potato field, located in Karlstad, Kittson County, Minnesota, USA. Two out of 175 vials submitted for identification to the Mycology and Nematology Genetic Diversity and Biology Laboratory (MNGDBL) contained few cysts and juveniles of C. torreyanae. Cysts were dark brown in color, lemon-shaped to elongated with distinct vulval cone. Vulva with denticles present around fenestra, cyst length to width ratio between 1.6 and 2.3 and anus distinct. The juveniles had rounded stylet knobs, some sloping slightly posteriorly. The molecular analysis included sequence and phylogenetic analysis of ITS rRNA, D2-D3 expansion segments of 28S rRNA and COI of mtDNA genes. The nematode species was identified by both morphological and molecular means as Cactodera torreyanae. To the best of our knowledge this represents the first report of Cactodera torreyanae from the United States and first report of this cyst nematode species from potato fields. Definite host plant for this nematode remains unknown. more...

Summary Cryphodera japonicum n. sp., detected at Ningbo port, China, from the rhizosphere of imported Japanese Podocarpus macrophyllus, is described. The new species is characterised by females with a globose body, protruding vulval lips, slightly concave anus-vulva profile, a stylet length of 37.2 (31.1-41.3) μm and a vulva-anus distance of 38.1 (34.7-44.1) μm. Males possess two lip annuli, a stylet length of 27 (22.5-30.6) μm long, three lines in lateral fields and a spicule 21.5 (19.1-23.0) μm long. Second-stage juveniles have bodies 543 (506-588) μm long, three lip annuli, a stylet 31.7 (29.2-34.5) μm long, three lines in the lateral fields, a conoid tail with a narrow rounded terminus, and a relatively long hyaline region occupying half of the tail length. Phylogenetic analyses based on the D2-D3 expansion segments of the 28S, ITS, partial 18S rRNA, and COI gene revealed the unique position of this species with other heteroderid nematodes, supporting its status as a new species of Cryphodera. The new species showed a close relationship with C. brinkmani. more...

The golden nematode, Globodera rostochiensis (Wollenweber, 1923) Skarbilovich, 1959 (Tylenchida: Heteroderidae) is one of the most economically important pests of potato in the world. Tests for this nematode are routinely performed for outbreaks and densities in potato growing areas. The morphological and molecular analyses for precise determination of the nematode are employed to establish appropriate management strategies. This study showed that 96% of soil samples obtained from Bozdağ and Ödemiş Districts of İzmir Province, during 2017 and 2018 potato growing seasons, were positive for G. rostochiensis. The mean number of cysts ranged from 0.01 to 3.70 cysts g-1 soil in the fields examined. The examination of the morphological and morphometric features of the second-stage juveniles and cysts of the G. rostochiensis revealed slight differences among the populations obtained from Bozdağ and Ödemis. To assess the accuracy of the identification, partial sequences of ribosomal DNA for all populations were amplified, sequenced, and deposited in GenBank. The comparisons of the sequences with those of corresponding G. rostochiensis populations available in GenBank showed 99.89-100% nucleotide similarity. The results of this study will help to better understand the physiology, ecology and biology of the nematode to quarantine this pest more effectively., Altın nematod, Globodera rostochiensis (Wollenweber, 1923) Skarbilovich, 1959 (Tylenchida: Heteroderidae) dünyada ekonomik açıdan en önemli patates zararlılarından birisidir. Genellikle patates yetiştirilen alanlarındaki dağılımları ve yoğunluklarını belirlemek amacıyla bu nematod için rutin olarak testler gerçekleştirilmektedir. Morfolojik ve moleküler analizler bu nematodun kesin tanısını yapmak ve mücadele stratejilerini oluşturmak amacıyla kullanılmaktadır. Bu çalışma, İzmir İli’nin Bozdağ ve Ödemiş ilçelerinden 2017 ve 2018 yılları patates yetiştiriciliği sezonlarında alınan toprak örneklerinin %96'sının G. rostochiensis ile enfekte olduğunu göstermiştir. Bulaşık alanlardaki ortalama kist sayısı, 0.01 ila 3.70 kist g-1 toprak arasında değişmiştir. Globodera rostochiensis'in ikinci dönem larva ve kistlerinin morfolojik ve morfometrik karakterlerinin incelenmesi, Bozdağ ve Ödemiş’ten elde edilen popülasyonlarda arasındaki hafif farklılıkları ortaya koymuştur. Tanımlamanın doğruluğunu değerlendirmek için, tüm popülasyonlar için kısmi ribozomal DNA sekansları amplifiye edilmiş, sekanslanmış ve GenBank veritabanına kaydedilmiştir. Morfolojik ölçümler ve filogenetik analizler sonucunda Bozdağ ve Ödemiş'ten elde edilen popülasyonlar arasında küçük farklılıkların olduğu belirlenmiştir. Sekansların GenBank'ta mevcut karşılık gelen G. rostochiensis popülasyonlarıyla karşılaştırılması sonucunda nükleotid benzerliği %99.89-100 oranında görülmüştür. Bu çalışmanın sonuçları, bu zararlıyı daha etkili bir şekilde karantinaya almak için nematodun fizyolojisini, ekolojisini ve biyolojisini daha iyi anlamaya yardımcı olacaktır. more...

In January 2017 Heterodera schachtii Schmidt, 1871 was collected from a potato field, formerly planted to cabbage, in the Tarlton area of South Africa. As H. schachtii from South Africa has never b... more...

Summary A new species of cyst-forming nematode, Cactodera solani n. sp., from Mexico is described. The new species was found in a glasshouse in Mexico City parasitising tomato and common lambsquarter. This cyst nematode has light brown to almost black cysts, presents a small vulval cone with circumfenestra and morphologically it most resembles C. milleri. Cactodera solani n. sp. can be differentiated from C. milleri by having smaller cysts that are 417 (291-581) × 324 (204-505) vs 632 (515-730) × 506 (419-598) μm in size and a longer stylet in the second-stage juveniles of 25 (24-27) vs 22 (21-23) μm. Phylogenetic relationships within populations and species of Cactodera are given based on the analysis of the ITS rRNA and the partial COI gene sequences. The ITS rRNA and COI gene sequences clearly differentiated C. solani n. sp. from other Cactodera species. This new cyst-forming nematode has several generations per year and its life cycle can be completed in 49 days on tomato and in 40 days on common lambsquarter at 20-25°C. more...

WOS:000529950700012 The Mediterranean cereal cyst nematode, Heterodera latipons Franklin, 1969 (Tylenchida: Heteroderidae) is a destructive plant-parasitic nematode on cereal crops in particularly wheat and barley. It has a global distribution with a severe negative impact on yield quantity. In this study, a survey was conducted to identify plant-parasitic nematodes in cereal-growing areas in Cyprus. Forty-five samples including roots and soil from the root zone of plants were collected from cereal fields located in Gazimagusa, Gime, Guzelyurt and Lefkosa Provinces before crop harvesting from late-May and early-June in 2017. Cyst-forming nematodes were determined by Fenwick's flotation and decanting techniques from 37 soil samples (82%). The internal transcribed spacer (ITS) regions of the ribosomal DNA of isolates were amplified and sequenced and subjected to a BLASTn search of the NCBI database for species identification, and the analyses showed that all samples were identified as H. latipons. Phylogenetic analyses based on ITS sequences revealed that H. latipons isolates from Northern Cyprus were closely related to isolates obtained from Morocco, Russia, Syria and Turkey. Data of this study demonstrated for the first time the presence of H. latipons in the cereal fields of Gazimagusa, Gime, Guzelyurt and Lefkosa Provinces, where the nematode most likely causes serious economic problems in the cereal production. These results were the most up-to-dated analyses on the occurrence of H. latipons in cereal fields of Northern Cyprus and provided basic data for breeding programs to improve the resistant levels in the local cultivars. Akdeniz tahıl kist nematodu, Heterodera latipons Franklin, 1969 (Tylenchida: Heteroderidae) özellikle buğday ve arpada olmak üzere tahıllarda önemli zararlara neden olan bir bitki paraziti nematod olup, dünyada tahıl yetiştirilen alanların büyük çoğunluğunda tespit edilmiştir. Bu çalışmada, Kıbrıs’ın tahıl alanlarındaki patojen nematodları belirlemek için bir sürvey yapılmıştır. Gazimağusa, Girne, Güzelyurt ve Lefkoşa tahıl üretim alanlarından toplam 45 adet toprak ve kök örneği 2017 yılının mayıs ayı sonu-haziran ayı başı arasında tahıl hasadı öncesinde alınmıştır. Toprak ve kök örneklerinden Fenwick yöntemii kullanılarak kistler toplanılmış, 37 adet örnekte (%82) kiste rastlanılmış olup, tüm örnekler ribozomal DNA’nın ITS bölgesi kullanılarak, tahıl kist nematodu H. latipons moleküler düzeyde tanımlanarak belirlenmiştir. Çalışmada Kuzey Kıbrıs arpa ve buğday alanlarından elde edilen H. latipons örneklerine ait ITS bölgesi sekans dizilerinin Fas, Rusya, Suriye ve Türkiye’den elde edilen izolatlara oldukça benzerlik gösterdiği tespit edilmiştir. Kuzey Kıbrıs'ın Gazimağusa, Girne, Güzelyurt ve Lefkoşa illeri tahıl alanlarında H. latipons'un ilk olarak tespit edildiği bu çalışma, nematodun yaygınlığını ortaya koyan ve zararlının mücadelesinde başta dayanıklı çeşit kullanımı olmak üzere diğer mücadele yöntemlerinin uygulanmasında temel oluşturacak verileri içermektedir. more...

Morphological and molecular analyses of plant-parasitic nematodes (PPN) from 12 sugarcane plantation sites of Tanganyika Planting Company (TPC) Limited in Kilimanjaro region of Tanzania revealed the presence of six PPN genera, i.e. Helicotylenchus, Hemicycliophora, Pratylenchus, Rotylenchulus, Scutellonema, and Tylenchorhynchus. The genera with the highest densities and present in virtually all samples were Pratylenchus and Rotylenchulus, and the most important species appeared to be R. parvus, P. zeae, T. crassicaudatus, and T. ventrosignatus. A total sequences of 11 partial ITS, 15 D2-D3 of 28S, and 6 partial 18S of rRNA gene, and 7 partial COI gene of mtDNA of these species were obtained in this study. Morphology and molecular data comparisons between the Tanzanian R. parvus and the South African R. parvus indicated that R. parvus is a cryptic species complex. Based on the results of morphological and molecular analyses of T. crassicaudatus and T. agri from China, Haiti, Indonesia, Iran, Niger and the USA, T. agri syn. n. is proposed as a junior synonym of T. crassicaudatus. Morphological and molecular analyses of plant-parasitic nematodes (PPN) from 12 sugarcane plantation sites of Tanganyika Planting Company (TPC) Limited in Kilimanjaro region of Tanzania revealed the presence of six PPN genera, i.e. Helicotylenchus, Hemicycliophora, Pratylenchus, Rotylenchulus, Scutellonema, and Tylenchorhynchus. The genera with the highest densities and present in virtually all samples were Pratylenchus and Rotylenchulus, and the most important species appeared to be R. parvus, P. zeae, T. crassicaudatus, and T. ventrosignatus. A total sequences of 11 partial ITS, 15 D2-D3 of 28S, and 6 partial 18S of rRNA gene, and 7 partial COI gene of mtDNA of these species were obtained in this study. Morphology and molecular data comparisons between the Tanzanian R. parvus and the South African R. parvus indicated that R. parvus is a cryptic species complex. Based on the results of morphological and molecular analyses of T. crassicaudatus and T. agri from China, Haiti, Indonesia, Iran, Niger and the USA, T. agri syn. n. is proposed as a junior synonym of T. crassicaudatus. more...

Radopholus similis (Cobb) Thorne (Tylenchida: Pratylenchidae) and Meloidogyne incognita Kofoid and White (Tylenchida: Meloidogynidae) are agriculturally important migratory endoparasitic and sedent... more...

The soybean cyst nematode, Heterodera glycines, is a major plant-parasitic nematode that has caused important economic losses to Korea’s soybean production. Four species of cyst nematodes, H. schachtii, H. glycines, H. trifolii, and H. sojae, all belong to schachtii group are coexist in field soil in Korea. The rapid identification of the nematode is crucial for preventing crop damage and in decision making for controlling this nematode. This study aimed to develop a species-specific primer set for quantitative PCR (qPCR) assay of H. glycines. The specific primer set (HGF1 and HGR1) for H. glycines was designed based on the cytochrome c oxidase subunit I (COI) sequence of mitochondrial DNA. After optimization, it is possible to identify the H. glycines using a qPCR assay with DNA extracted from a single cyst and single second-stage juvenile (J2). The specificity was confirmed by the absence of SYBR fluorescent signals of three other Heterodera species. A serial dilution of DNA extracted from a single cyst was obtained for the sensitivity test. The result showed that the standard curve of the test had a highly significant linearity between DNA concentration and Ct value (R2 = 0.996, slope = −3.49) and that the detection limit concentration of DNA of the primer set was 10 pg of DNA per reaction. Our findings suggested that H. glycines could be distinguished from H. sojae and other Heterodera species when a qPCR assay is used with a specific primer set. more...

Potato (Solanum tuberosum L.) cyst nematodes (Globodera rostochiensis (Wollenweber) and Globodera pallida (Stone) cause significant yield losses and have been listed as quarantine pests for many countries in the world including Turkey, and the European and Mediterranean Plant Protection Organization (EPPO, A2). In Turkey, the current potato production area is decreasing due to contamination by quarantine agents, and new fields are under threat of invasion by new quarantine organisms. In this study, samples were collected from Nevşehir province, Turkey, in potato growing fields during the spring growing season in 2014-2015. Soil samples were washed using Fenwick’s can and cysts were extracted and identified using molecular markers. The species-specific molecular markers generated a 435 bp using PITSr3, PITSp4 and ITS5 primers. The potato golden cyst nematode, G. rostochiensis was identified in Nevşehir potato production areas and this is the first report for the Central Anatolia Region. In addition, G. rostochiensis was found in two samples of the same field in the surveys. The average cyst nematode density was determined as 60 cysts in 250 g soil. Patates (Solanum tuberosum L.) kist nematodları (Globodera rostochiensis (Wollenweber) ve Globodera pallida (Stone) önemli verim kayıplarına neden olmakta, Türkiye de dahil olmak üzere dünyadaki birçok ülke, Avrupa ve Akdeniz Bitki Koruma Örgütü’nde (EPPO, A2) karantina zararlıları olarak listelenmiştir. Türkiye'de mevcut patates üretim alanı karantina zararlısı olarak bulaşmaya bağlı olarak azalmakta ve yeni alanlar yeni karantina organizmaları tarafından istila tehdidi altında bulunmaktadır. Bu çalışmada, Türkiye, Nevşehir ilinden 2014-2015 yıllarında bahar mevsiminde patates yetiştirme alanlarında örnekler toplanmıştır. Toprak örnekleri Fenwick aletinde yıkanarak bulaşık örneklerdeki kistler elde edilmiş ve kist popülasyonlarının moleküler olarak teşhisleri yapılmıştır. Kist popülasyonlarının moleküler düzeyde türe özgü PITSr3, PITSp4 ve ITS5 primerleri kullanılarak yapılan teşhiste söz konusu primerlerin 435 bp de bant oluşturduğu tespit edilmiştir. Bu çalışma sonucunda Nevşehir ili patates ekiliş alanlarında patates kist nematodu G. rostochiensis saptanmış olup, bu sonuç İç Anadolu Bölgesi için ilk kayıt olma özelliğini taşımaktadır. Ayrıca, sürveylerde aynı tarlaya ait iki örnekte G. rostochiensis’e rastlanılmış, 250 g toprakta ortalama 60 kist yoğunluğunda olduğu tespit edilmiştir. more...

During a survey in 2018 for plant nematodes associated with roots and soil in cactus cultivation areas in Ceara State (3°44'48"S, 38°34'29"W), cysts were found on roots of mandacaru, Cereus jamacaru DC. This cactus is native to Brazil, can grow to 6-10 meters in height, and is widely distributed in the Northeast region (Romeiro-Brito et al. 2016) where it is used in construction, in disease remedies, as forage, and as an ornamental (Sales et al. 2014). Several cysts, second-stage juveniles (J2) and eggs extracted from the soil and roots, using sucrose centrifugation, were examined by scanning electron microscopy (SEM) and light microscopy (LM) to determine morphological and morphometric characteristics. Molecular characteristics were determined by DNA extraction from J2 and embryonated eggs using a protocol specific for Heteroderidae (Subbotin et al., 2018). The internal transcribed spacer sequence (ITS) region of the rDNA and D2-D3 regions of the 28S rDNA were amplified using the universal primers TW81 (5'-GTTTCCGTAGGTGAACCTGC-3') and AB28 (5'-ATATGCTTAAGTTCAGCGGGT-3'), D2A(5'-ACAAGTACCGTGAGGGAAAGTTG-3') and D3B(5'-TCGGAAGGAACCAGCTACTA-3'), respectively. To confirm that mandacaru is a host for C. cacti, six plantlets of mandacaru were inoculated with 1,800 eggs of the nematode, and kept in a greenhouse at 31 ± 3 oC and irrigated daily. Six non inoculated mandacaru plantlets served as control treatment. Morphometric characteristics of cysts (n=35) were body length, excluding neck, 555.8 ± 87.8 (354,9 - 727,6) μm, body width 392.1 ± 63.4 (297.9 - 553.7) μm, neck length 63.5 ± 25.8 (49.8-105.0) μm, length to width ratio 1.4 ± 0.2 (1.0-1.8) μm and vulval cone length 48.4 ± 15.2 (40.7 -53.6) μm. Cysts had a rough surface, were lemon-shaped to rounded and had a zigzag cuticular pattern with a protruding vulval cone. They were circumfenestrate without underbridge and bullae, but with the presence of vulval denticles. Measurements of second-stage juveniles (n = 13) included the body length 511.2 ± 33.7 (452.7 - 551.5) μm, stylet length 28.0 ± 2.8 (25.4 - 34.0) μm, tail length 50.7 ± 5.1 (40.6 - 57.4) μm, tail hyaline region 22.7 ± 2.2 (18.9 - 27.1), with a = 20.9 ± 2.2 (17.7-24.3) μm, b = 5.4 ± 0.4 (5.1-5.8) μm, b'= 3.4 ± 0.4 (3.1-3.9) μm, c = 10.2 ± 1.3 (8.9-13.3) μm and c' = 3.8 ± 0.4 (3.0-4.5) μm. The observations of essential morphological characteristics for identification indicated that the species found on C. jamacaru was Cactodera cacti (Filipjev & Schuurmans-Stekhoven, 1941) Krall & Krall, 1978. The sequences of the studied rDNA regions were submitted to GenBank (ITS: MW562829 and D2-D3 regions of 28S: MW562830). The samples used for molecular analysis showed a high degree of sequence identity (99.59%) with C. cacti, from China, Iran and USA for the ITS region. The identity of the D2-D3 regions of 28S sequence was 99.54% with C. cacti isolates from Germany and 99.41% with isolates from USA. Phylogenetic analyses were performed using Maximum likelihood (ML) method for both individual loci, confirming the species as Cactodera cacti. All inoculated mandacaru plantlets showed C. cacti cysts on the roots after 60 days, confirming that mandacaru is a host for C. cacti. This species was reported in Sao Paulo State, in 2001, associated with ornamental cactus cultivated in pots, but plant species were not identified (Santos et al., 2001). The second report in Brazil was to Schlumbergera sp., an ornamental plant (Oliveira et al. 2007). In both studies, the nematode was not morphologically nor molecularly characterized. Cactodera cacti has been commonly associated with cactus worldwide (Esser, 1992). It has been reported in association with C. jamacaru was first reported in 2011 in China (Duan et al. 2012). This is the first report of the occurrence of C. cacti on C. jamacaru in field conditions in Brazil, and its presence in cactus cultivation areas with agricultural importance represents a threat to cactus production in the country. more...

Morphological and molecular studies were conducted to characterize the specific identity of 36 isolates of potato cyst nematodes (PCNs) recovered from soil samples collected in several potato producing areas of Algeria. Morphometric data revealed that 44% of isolates contained Globodera pallida alone, 28% contained Globodera rostochiensis alone and 28% mixtures of the two species. Morphometric values of cysts and second-stage juveniles were generally distributed with slight differences in the expected ranges for both Globodera species. Inter- and intraspecific morphometric variability in nematode isolates was noted. Molecular analysis using conventional multiplex PCR with species-specific primers and TaqMan real-time PCR confirmed the morphological identification. In addition, the distribution of both potato cyst nematode species throughout various parts of the country was investigated. In the central areas, the isolates of G. pallida alone dominate, whereas isolates of G. rostochiensis alone are more frequent in the southern areas. In the eastern regions, mixed isolates are more representative. Most isolates examined in the western areas are mixtures of the two species or G. rostochiensis alone. Comparatively, G. pallida remains the most widely distributed species in its geographic range. This study confirms the presence of two PCN species, G. pallida and G. rostochiensis, in Algeria and provides additional information on their biogeographic distribution. more...

The identification and phylogenetic relationships of potato cyst nematodes (PCN) were studied to assess the potential value of geographical distribution information for integrated pest management of potato production in Portugal. This research focused on PCN species, Globodera pallida and Globodera rostochiensis. From 2013 until 2019, 748 soil samples from the rhizosphere of different potato cultivars were surveyed in the Portuguese mainland to detect and identify both species and track their location. PCN are widespread invasive species throughout Portugal. In fact, during the survey period an incidence of 22.5% was estimated for the tested samples. The patterns of infestation vary among regions, increasing from south to north, where PCN were first detected. Currently, both species are present in all potato producing regions of the country, with a greater incidence of G. pallida. Phytosanitary control measures are influencing to the observed results. The use of potato cultivars resistant to G. rostochiensis led to a decrease of this species but had no influence on G. pallida detections, which continues its reproduction freely since there are no effective resistant cultivars for this species. The relationship between the presence, infestation rate, spread and geographical distribution of PCN is discussed in terms of behavioral responses of the potato cultivars and the implications for developing new integrated crop protection measures. more...

The history of the higher classification of nematodes spans just a little more than 100 years when Orley proposed grouping similar nematode genera into families. Chitwood, recognizing his earlier error, accepted the phylum designation Nemates as proposed by Cobb but amended the spelling to Nemata in order to conform with the Pearse system for nomenclatorial endings; however, his classification essentially remained the same. In Nemata the phytoparasitic nematodes of the orders Dorylaimida and Tylenchida are among the most taxonomically abused groups in the phylum. The phylum Nemata is sometimes listed as a class in the phylum Nemathelminthes or Aschelminthes, groups whose membership or status is continuously being challenged. The subclass is divided into two superorders: Marenoplica and Terrenoplica. The superfamily contains seven families: Tylenchidae, Anguinidae, Dolichodoridae, Belonolaimidae, Pratylenchidae, Hoploaimidae, and Heteroderidae. Classifications are constructed from the foundation rank up, from the top down; however, systematists are obliged to write classifications from the top down. more...

The potato cyst nematode (PCN) Globodera rostochiensis is a plant parasite of potato classified into a group of quarantine organisms causing high economic losses worldwide. Due to the long persistence of the parasite in soil, cysts harbor numerous bacteria whose presence can lead to cyst death and population decline. The cysts of G. rostochiensis found in two potato fields were used as a source of bacteria. The universal procedure was applied to extract DNA from bacteria which was then sequenced with 16S primers. The aims of the study were to identify bacterial microbiota associated with the PCN populations and to infer their phylogenetic relationships based on the maximum likelihood and Bayesian phylogeny of the 16S sequences. In addition, the impact of the most significant climate and edaphic factors on bacterial diversity were evaluated. Regarding the higher taxonomy, our results indicate that the prevalent bacterial classes were Bacilli, Actinobacteria and Alphaproteobacteria. Phylogenetic analyses clustered Brevibacterium frigoritolerans within the family Bacillaceae, confirming its recent reclassification. Long-term climate factors, such as air temperature, insolation hours, humidity and precipitation, as well as the content of soil organic matter, affected the bacterial diversity. The ability of cyst nematodes to persist in soil for a long time qualifies them as a significant natural source to explore the soil bacterial microbiota. more...

This study evaluated the occurrence and incidence of phytophagous nematodes and identified the cereal cyst nematode species by morphological and molecular tools in the main cereal-growing areas in Niğde in 2018-2019. Phytophagous nematodes within twelve genera were detected in 95% of soil samples. The most common phytophagous nematodes in cereal soil were in the genera Heterodera, Ditylenchus, Merlinius, Pratylenchus, Aphelenchus, Aphelenchoides, Tylenchus, Helicotylenchus, Trophurus, Pratylenchoides, Filenchus and Xiphinema (in decreasing order of incidence). In particular, 75% of the soil samples from surveyed fields were infested with the cereal cyst nematodes (Heterodera spp.). Morphological characteristics of cysts and second-stage juveniles were calculated within the expected ranges for Heterodera filipjevi (Madzhidov, 1981) Stelter, 1984, however, two populations from Çamardı was determined as Heterodera latipons Franklin, 1969 (Tylenchida: Heteroderidae). Intraspecific variation was not observed within the populations of H. filipjevi which could be in the same genotypic group. In addition to the high incidence of these Heterodera spp., intensive cereal cropping systems with/without non-cereal rotations in wheat production areas of Niğde also resulted in high incidence of root lesion nematode, Pratylenchus species., Bu çalışma ile 2018-2019 yıllarında Niğde İli'ndeki başlıca tahıl yetiştirme alanlarında bulunan fitofag nematodların yoğunluk ve dağılımı belirlenmiş, tahıl kist nematodu türlerinin morfolojik ve moleküler yöntemlerle tanımı yapılmıştır. Fitofag nematodlar 12 cins olarak toprak örneklerinin %95'inde tespit edilmiştir. En yaygın fitofag nematodlar sırasıyla, Heterodera, Ditylenchus, Merlinius, Pratylenchus, Aphelenchus, Aphelenchoides, Tylenchus, Helicotylenchus, Trophurus, Pratylenchoides, Filenchus ve Xiphinema cinsleridir (bulunma yoğunluğuna göre sıralanmıştır). İncelenen toprak örneklerinin %75’inde tahıl kist nematodu (Heterodera spp.) bulunmuştur. Kistlerin ve 2. dönem larvaların ölçümleri ve morfolojik karakterlerinin değerlendirilmesiyle elde edilen sonuçlarda Heterodera filipjevi (Madzhidov, 1981) Stelter, 1984 olarak tespit edilmiş olup sadece Çamardı’dan iki popülasyon Heterodera latipons Franklin, 1969 (Tylenchida: Heteroderidae) olarak belirlenmiştir. Heterodera filipjevi’nin tür içi varyasyonlarına bakıldığında hepsinin aynı gurupta olabileceği değerlendirilmiştir. Buna ilave olarak tahıl kist nematodları yanında kök lezyon nematodlarının, Pratylenchus türlerinin de rotasyon yapılan/yapılmayan Niğde İli tarım alanlarında yüksek yoğunlukta bulunduğu sonucuna varılmıştır. more...

The purpose of the research is study of the main sources and ways of dispersal of heteroderidae.Materials and methods. The research was conducted from 2002 to 2018 in Sumy, Chernihiv, Cherkasy, Poltava and other regions of Ukraine. The study of the features of the spatial dispersal of cyst nematodes in cultural and natural plant communities was carried out by the method of selection and analysis of plant and soil samples. Cysts from the soil were extracted by the flotation method. To determine the species composition of nematodes, temporary and permanent specimens were prepared according to generally accepted methods.Results and discussion. Wind erosion is one of the dominant sources of cysts dispersal. In natural biocoenosis, mole rats and moles are potential sources of the distribution of clover and other types of cyst nematodes. Among mouse-like rodents, representatives of the genus of gray voles are the most important, populating both cultural and natural plant communities. The dispersal of cysts can also occur in soil insects: bitterns, scarab beetles, carrion beetles, larvae of the May beetle, cut worms. However, the greatest dispersal of cysts occurs as a result of human activities. Cysts are also distributed by hand tools: shovels, rakes, hoes when performing various agricultural works on tillage. The implementation of a set of recommended technological operations for growing sugar and fodder beets leads to an increase in the area of existing foci within 90–170 cm, potatoes 75–125 cm, corn for green fodder and silage 30–85 cm, peas 18–55 cm, barley with clover seeding of 12–40 cm, winter cereal when using no-till and mini-till of 16–35 cm, and tail (plowing) and subsequent superficial 31–50 cm. The smallest up to 10 cm dispersal of cyst-forming nematodes was noted when growing perennial legumes in that due to the minimal number of mechanical operations for their maintenance. more...

The golden potato cyst nematode (GPCN) Globodera rostochiensis (Wollenweber, 1923) Skarbilovich, 1959 is a highly specific parasite of the roots of the nightshade plants (Solanaceae). Thus, the state of the pest population demands constant monitoring and control of distribution and numbers. The distribution of G. rostochiensis in Volyn region of Ukraine was studied in 2008–2018 using the data of the state institution the Volyn Regional Phytosanitary Laboratory. The present article gives the analysis of the study results. The disease foci were detected by visual above-ground inspection of potato plantings, also by manually collecting soil samples before planting the potatoes and after harvesting, and consequently analyzing theme. The initial (pre-planting) and conclusive (after harvest) population density of GPCN in the soil was determined by the number of cysts and the mean number of larvae and eggs in cysts obtained from 100 cm3 of soil. Cysts were isolated from soil samples by the standard funnel flotation method. The dead and living larvae were identified visually by the shape of the body and the state of internal organs. According to the results of assessing pre-planting and post-harvest nematode numbers in soil, the reproduction coefficient Рf/Рі was calculated. In Volyn region, G. rostochiensis was first observed in 1968 on farmland and since then, the parasite has spread. Pest foci were recorded in 15 districts of the region in 303 settlements on the area of 946.123 hectares. It was however found that during the latest decade, the area of soils affected by G. rostochiensis in Volyn region decreased by 147.647 hectares. The largest infected areas (over 100 ha) were located in Kovel, Rozhyshche and Manevistky districts, the least infected area was observed in Ivanychi district of the region. The pest was not found in Lutsk district. The highest infection rate was recorded in Rozhyshche district. The highest ratio of viable cysts was observed in the soils of Volodymyr-Volynsky and Rozhyshche districts. The soils of the southern districts (located in the natural zone of forests and steppe) of the region demonstrated 1.5 times higher infection rates compared to soils of the northern districts (in the natural zone of mixed forests). The soils of the southern districts also harboured stable and strong pest populations. The pre-planting soil infection rates proved to directly depend on the reproduction coefficient of GPCN. If the values of Рі, initial infection rate, were lower than 1,000 larvae and eggs per 100 cm3, the reproduction coefficient was 1.18. Increase in the pre-planting infection rate to 2,000 eggs and larvae per 100 cm3 did not affect the reproduction coefficient. At approximately 5,000 eggs and larvae per 100 cm3 the reproduction coefficient exceeded 2, which should be considered in developing the pest control measures. more...

Root-knot nematodes are one of the most harmful plant-parasitic nematodes (PPNs). In this paper, the predation of Stratiolaelaps scimitus against Meloidogyne incognita was tested in an individual arena, and the control efficiency of the mite on the nematode in the water spinach (Ipomoea aquatica) rhizosphere was studied with a pot experiment. The results showed that S. scimitus could develop normally and complete its life cycle by feeding on second-stage juveniles of M. incognita (Mi-J2). The consumption rate of a 24 h starving female mite on Mi-J2 increased with the increase of prey density at 25 °C. Among the starvation treatments, the nematode consumption rate of a female mite starved for 96 h at 25 °C was highest; and among temperature treatments, the maximum consumption rate of a 24 h starving female mite on Mi-J2 was at 28 °C. The number of M. incognita in the spinach rhizosphere could be reduced effectively by releasing S. scimitus into rhizosphere soil, and 400 mites per pot was the optimum releasing density in which the numbers of root knots and egg masses decreased by 50.9% and 62.8%, respectively. Though we have gained a greater understanding of S. scimitus as a predator of M. incognita, the biocontrol of M. incognita using S. scimitus under field conditions remains unknown and requires further study. more...

Egg masses and females of Meloidogyne incognita from a tomato (Lycopersicon esculentum Mill. cv. Falcon) field from Central Anatolia of Turkey, were collected and examined for the presence of fungi. Of the 138 egg masses of M. incognita 35.5% were colonized by one or more of 9 species of genera Arthrobotrys, Cylindrocarpon, Fusarium, Paecilomyces, Plectosphaerella, Rhizoctonia and Verticillium while 31.8% of the 138 females were colonized by 6 species, from the same genera except Paecilomyces and Plectosphaerella. Fusarium oxysporum was by far the predominant species in both the egg masses and females of M. incognita. more...

The root-knot nematode speciesMeloidogyne daklakensisn. sp. was discovered on the roots of Robusta coffee (Coffea canephoraPierre ex A. Froehner) in Dak Lak Province, Vietnam. This species is characterized by the females having rounded or oval perineal patterns, smooth, regular, continuous striae, and reduced lateral lines. The dorsal arch is low, rounded and encloses a quite distinct vulva and tail tip. The stylet is normally straight with well-developed and posteriorly sloped knobs. The males have a rounded cap that extends posteriorly into the lip region. The procorpus is outlined distinctly, and is three times longer than the metacorpus. The metacorpus is ovoid, with a strong valve apparatus. The species closely resemblesM. marylandi,M. naasi, M. ovalis, M. panyuensis, M. lopezi, M. maliandM. baeticain the perineal pattern of the females, and the morphology of the males and the second-stage juveniles. Nonetheless, it can be differentiated from other species by a combination of morphometric, morphological and molecular characteristics. Phylogenetic analysis was conducted based on the internal transcribed spacer (ITS) and 28S rDNA as well as the region between the cytochromecoxidase I (COI) and cytochromecoxidase II (COII) mitochondrial genes. Herein, this nematode is described, illustrated, and designated as a new species,Meloidogyne daklakensissp. n., based on morphometric, morphological and molecular analyses. more...

A cultura do algodão tem grande importância econômica e social para o Brasil, no entanto proporciona também impactos ambientais relevantes. Para mensurar esses impactos faz-se uso da dinâmica populacional de nematoides em agroecossistemas como indicador de qualidade de solos. Diante disso, o objetivo do trabalho foi caracterizar a comunidade de nematoides em habitat cultivado com algodão em diferentes estádios fenológicos da cultura. Foram coletadas duas amostras de solo, na profundidade de 30 cm, por área (talhão) e estádio fenológico (inicial, antes da cultura ser implantada; vegetativo; reprodutivo e maturidade fisiológica). Foram realizadas as análises de riqueza, abundância, frequência de ocorrência (FO), índice pontual de abundância (IPA), índice de diversidade de Shannon (H’) e registrados os dados meteorológicos. No total foram identificados 4.400 indivíduos (abundância), distribuídos em seis famílias (Aphelenchidae, Aphelenchoididae, Heteroderidae, Hoplolaimidae, Pratylenchidae e Tylenchidae). Os gêneros predominantes foram Helicotylenchus (64,77%), Pratylenchus (15,45%) e Aphelenchus (9,32%). Em todas as amostras, o número de indivíduos fitoparasitas foi maior que o de micófagos. Os estádios vegetativo e de maturação fisiológica, apresentaram a maior população de micófagos no talhão 5 (Th5) e no estádio inicial e na maturação fisiológica no talhão 11 (Th11). Quanto à riqueza, os dois talhões apresentaram o mesmo número de gêneros. Sendo identificado como exclusivos o gênero Meloidogyne no Th5 e o gênero Tylenchus no Th11. Considerando a FO, os gêneros Aphelenchus, Helicotylenchus e Pratylenchus foram observados em 75% das amostras no Th5 e Helicotylenchus (100%) e Pratylenchus (50%) no Th11. Resultados semelhantes da FO foram observados para o IPA, acrescentando-se o gênero Aphelenchoides no Th11. Quanto ao H’, observou-se uma diversidade total de 0,60 com o valor do Th5 inferior ao Th11. Ao analisar a correspondência canônica (CCA), observou-se que os dados meteorológicos não interferiram diretamente na flutuação populacional de nematoides nos dois talhões. Sendo assim, observou-se que a comunidade de nematoides estudada neste trabalho, foi composta na maior parte, pela população de fitoparasitas e a maturidade fisiológica do algodoeiro foi o estádio fenológico com a maior obtenção de indivíduos tanto fitoparasitas quanto micófagos. more...

Root-knot nematodes are one of the most harmful plant-parasitic nematodes (PPNs). In this paper, the predation of Stratiolaelaps scimitus against Meloidogyne incognita was tested in an individual arena, and the control efficiency of the mite on the nematode in the water spinach (Ipomoea aquatica) rhizosphere was studied with a pot experiment. The results showed that S. scimitus could develop normally and complete its life cycle by feeding on second-stage juveniles of M. incognita (Mi-J2). The consumption rate of a 24 h starving female mite on Mi-J2 increased with the increase of prey density at 25 °C. Among the starvation treatments, the nematode consumption rate of a female mite starved for 96 h at 25 °C was highest; and among temperature treatments, the maximum consumption rate of a 24 h starving female mite on Mi-J2 was at 28 °C. The number of M. incognita in the spinach rhizosphere could be reduced effectively by releasing S. scimitus into rhizosphere soil, and 400 mites per pot was the optimum releasing density in which the numbers of root knots and egg masses decreased by 50.9% and 62.8%, respectively. Though we have gained a greater understanding of S. scimitus as a predator of M. incognita, the biocontrol of M. incognita using S. scimitus under field conditions remains unknown and requires further study. more...

In the summer of 2016, a field of corn (Zea mays) in Spencer County, Indiana was observed with heavily stunted plants, and from the affected roots a large number of cysts were recovered. Soil samples were submitted to one of us (JF), who extracted the nematode cysts and sent them to the USDA-ARS, Mycology and Nematology Genetic Diversity and Biology Laboratory (MNGDBL), Beltsville, MD for morphological and molecular identification. Cysts and the recovered second-stage juveniles (J2) that were examined morphologically conformed to the measurements of Vittatidera zeaphila, the goose cyst nematode originally described from Tennessee, USA in 2010. The molecular analysis of J2 showed the sample from Spencer County matched exactly with V. zeaphila according to ribosomal DNA markers ITS, 28S, and 18S, and with mitochondrial cytochrome oxidase I (COI). The nuclear marker heat shock protein 90 (Hsp90) was also analyzed for the first time from the Indiana population of V. zeaphila. Similarities to existing cyst nematode sequences are reported herein. Geographically, although the county is across the Ohio River from Kentucky, the previously reported Hickman County, Kentucky location and Indiana detection are approximately 200 miles apart. To the best of our knowledge, this is the first report of V. zeaphila in Indiana. In the summer of 2016, a field of corn (Zea mays) in Spencer County, Indiana was observed with heavily stunted plants, and from the affected roots a large number of cysts were recovered. Soil samples were submitted to one of us (JF), who extracted the nematode cysts and sent them to the USDA-ARS, Mycology and Nematology Genetic Diversity and Biology Laboratory (MNGDBL), Beltsville, MD for morphological and molecular identification. Cysts and the recovered second-stage juveniles (J2) that were examined morphologically conformed to the measurements of Vittatidera zeaphila, the goose cyst nematode originally described from Tennessee, USA in 2010. The molecular analysis of J2 showed the sample from Spencer County matched exactly with V. zeaphila according to ribosomal DNA markers ITS, 28S, and 18S, and with mitochondrial cytochrome oxidase I (COI). The nuclear marker heat shock protein 90 (Hsp90) was also analyzed for the first time from the Indiana population of V. zeaphila. Similarities to existing cyst nematode sequences are reported herein. Geographically, although the county is across the Ohio River from Kentucky, the previously reported Hickman County, Kentucky location and Indiana detection are approximately 200 miles apart. To the best of our knowledge, this is the first report of V. zeaphila in Indiana. more...

Root-knot nematodes (Meloidogyne spp.) are endoparasites which cause severe losses in grapevine. To ensure economically viable grape production, it is important that nurseries produce rooted nursery material free of plant-parasitic nematodes. Hot water treatment (HWT) at 50°C for 45 min to eliminate root-knot nematode (RKN) from rooted nursery material was investigated as a method to ensure nematode free plant material. Rooted grapevine rootstocks known to be susceptible (US 8-7 and 110 Richter), moderately resistant (1103 Paulsen and 143 B) and resistant (Ramsey) to Meloidogyne javanica were artificially infested by inoculating them with RKN eggs and larvae. After one growing season, the vines were lifted, shoots and root systems trimmed and subjected to different HWT regimes viz. 50°C for 45 min and 55°C for 20 min, while some were left as untreated controls. To evaluate plant response, each vine was planted in a pot, together with a three-week old tomato seedling as an indicator of root-knot nematode infestation. The tomato plants were removed after 12 weeks and their roots examined for the presence of M. javanica galls and egg masses. At the end of the growing season, the effects of the treatments on plant growth were assessed by determining total shoot and root mass. The results demonstrated that HWT at 55°C for 20 min significantly reduced the nematode populations in the rooted stocks, but did not eliminate the nematodes from the roots since indicator plants from HWT vines still supported a small number of galls. HWT at 55°C for 20 min also reduced the level of infestation of RKN in grapevine planting material, but resulted in a significant reduction in growth. more...

Effects of Pseudomonas fluorescens L. (jimsonweed) (Pf) isolate and the two plant extracts, Datura stramonium and Myrtus communis, were investigated on hatching and juvenile (J2s) mortality of Meloidogyne javanica(Tylenchida: Heteroderidae) under laboratory conditions. After determining the values of LC30, LC50, and LC70 of each extract, four leaf stage seedlings of tomato were treated by 20 ml of Pf suspension at a concentration of 108 CFU/ml, using a soil drenching method. After 1 week, the tested plants were inoculated by 4000 eggs and (J2s) of M. javanica and simultaneously were treated by 100 ml of the selected concentrations of D. stramonium (1.1, 1.4, and 1.8%) and M. communis (1.8, 3 and 5.2%), as soil drench. Results showed that a combination of Pf and the leaf extract, D. stramonium at the rate of 1.8% or M. communis at the rate of 5.2%, respectively, reduced the number of eggs per root system and the reproduction factor by 68 and 45%, the number of galls by 64 and 33%, and the number of egg masses by 65 and 43%, than the control. In conclusion, combination of Pf and D. stramonium at the rate of 1.8% or M. communis at the rate of 5.2% can significantly reduce the damage of M. javanica on tomato, under greenhouse conditions. more...

The cystoid nematodes of the subfamilies Ataloderinae and Meloidoderinae include 32 recognized species belonging to 10 genera. The geographical distribution and preferred hosts of these nematodes are reviewed in the present paper. Most genera in Ataloderinae are believed to have evolved in North America, but some genera currently show different or wider distributions. Although members of Bellodera, Ekphymatodera, Rhizonemella and Sarisodera have only been recovered from North America, those of Atalodera may be found in both North America and South America. Species of the other genera tend to occur in different geographical locations: Cryphodera species have been recorded in Asia and Oceania while Camelodera and Hylonema species have only reported from Asia and Africa, respectively. Members of Meloidoderinae (Meloidodera spp.) are distributed in North America, Asia and Europe. Plant hosts for the cystoid nematodes are distributed among both monocots and dicots. Nematologists suggest an ancient origin for genera such as Meloidodera, Cryphodera and Rhizonemella which can parasitize gymnosperms. more...

Accurate identification of Meloidogyne spp. is crucial and the first step to apply suitable management strategies to combat these nematode pests. Perineal-pattern morphology of female specimens is one of the most common characteristics used for identification. However, for some species various morphological characteristics are similar which makes it challenging to correctly identify species. In this study different morphological and morphometrical characteristics were used to identify 37 populations of Meloidogyne obtained during 2015 and 2016 from various crop production areas situated across different geographical regions in South Africa. A comprehensive study of females, males and second-stage juveniles (J2) of the 37 Meloidogyne populations isolated was conducted, revealing the presence of Meloidogyne enterolobii, M. hapla, M. incognita and M. javanica. Although three perineal-pattern characteristics proved to be useful in discriminating particularly between M. enterolobii and M. incognita females, most of the morphometric characters used to identify female, male and J2 individuals overlapped among the different species. Substantial intraspecies variation was also evident among different populations. The use of classical identification approaches alone could therefore not clearly distinguish among the 37 Meloidogyne populations studied. Therefore, the use of molecular techniques in combination with morphological and morphometrical analyses is suggested to be more accurate and reliable in discriminating between Meloidogyne spp. more...

The soybean aphid (SBA; Aphis glycines Matsumura) and the soybean cyst nematode (SCN; Heterodera glycines Ichninohe) are major pests of the soybean (Glycine max (L.) Merr.). Independent studies on these pests have made substantial progress in understanding the genetic basis of limiting these pests in both model and non-model plant systems. Classical linkage mapping and genome-wide association studies (GWAS) have identified some major and minor QTLs in soybean. The studies on interactions of aphid and nematode effectors with host proteins allow us to identify molecular cues in various signaling components, including plant disease resistance and phytohormone genes. Here we review various resistance components of both SBA and SCN in terms of their effectors, their role in eliciting or attenuating host defense and update on findings on key quantitative trait loci (QTLs)/genes in soybean that could help in mitigating these widespread shifted virulent soybean aphid and SCN populations. We also provide an update on recent interaction studies of soybean-soybean aphid-SCN as well as interaction studies involving different aphids/nematodes and their host systems. PHYTOALEXIN DEFICIENT4 (PAD4) in soybean could possibly play a major role in providing resistance against both soybean aphid and SCN. more...

The cyst nematode Heterodera latipons Franklin, 1969 (Nemata: Heteroderidae) is an economically important sedentary plant-parasitic nematode which limits the production of cereal crops around the world. It is an important pest on wheat and can be found globally in different growing areas, especially in the Mediterranean region. Developing an understanding of its physiological behavior (senescence, quiescence, and cryptobiosis), development [second-stage juveniles (J2) and immature and mature females], and population dynamics under field conditions is needed to create an appropriate control strategy. The experiments were conducted at Karaisali, a semiarid region in Adana Province, and at Derik, an arid region in Mardin Province, during the 2015-2016 and 2016-2017 growing seasons. The results indicated that the emergence of J2 of H. latipons in the soil rhizosphere occurred from late December to mid-January in the semiarid region, while they were mostly observed through March in both regions when the average temperature was around 10 degrees C. The white (immature) females were seen between mid-February and mid-March in both experimental seasons in the arid and semiarid regions, and they were mainly observed in April when the temperature was above 15 degrees C during both seasons in the arid region. The results showed that H. latipons produces only one generation in each wheat growing season, and the developmental stages of this nematode species are closely related to the ecological and edaphic factors of host plant development. Moreover, the development of J2 and immature females of H. latipons took longer in the semiarid region than in the arid region owing to plant and root growth and edaphic factors, especially soil temperature and moisture. Understanding the physiological behavior and biological stages of this nematode will be useful for developing nematode control strategies to keep H. latipons populations below economic damage levels. more...

The cystoid sedentary nematodes of the Heteroderidae include more than 30 recognised species belonging to from nine to 11 genera, depending on the opinion of the authority. In the present study, we collected nematode populations of species belonging to some of these genera, as well as other cyst-forming species from different locations in the USA, Vietnam, Germany and Russia. The populations of cystoid nematodes represent seven valid species, Atalodera carolynae, Cryphodera sinensis, Meloidodera astonei, M. floridensis, M. mexicana, M. sikhotealiniensis, Rhizonemella sequoiae, two unidentified species of Atalodera, six unidentified species of Cryphodera, and three putative new species of Rhizonemella. We also obtained samples of cyst-forming nematodes that include an unidentified species of Betulodera from California, and Heterodera guangdongensis from Vietnam. A population of Rotylenchulus sp. from Arizona, intercepted in Florida, and a population of an unidentified species of Verutus from Germany were also added to this study. All of these populations were characterised using sequences of the D2-D3 of 28S rRNA, ITS rRNA or mitochondrial COI genes. A total of 89 new sequences were obtained from these analyses. Phylogenetic relationships within the family Heteroderidae were reconstructed based on the D2-D3 of 28S rRNA, ITS rRNA and mitochondrial COI gene sequences. Results revealed that the subfamily Ataloderinae was paraphyletic. Ekphymatodera thomasoni, a non-cyst-forming species, clustered with the cyst-forming nematodes. Representatives of the subfamily Verutinae formed clades within Heteroderidae. The genus Meloidodera was non-monophyletic and distributed within two clades: i) M. sikhotealiniensis and Cryphodera spp. from Asia and Europe; and ii) M. astonei, M. floridensis and M. mexicana from North America. Based on comparative molecular analysis Meloidodera alni syn. n. is proposed as a junior synonym of M. sikhotealiniensis. Problems of taxonomy and phylogeography of cystoid nematodes are also discussed. more...

The Japanese populations of the clover cyst nematode,Heterodera trifolii, were characterised morphologically, morphometrically and molecularly. The morphology and morphometrics of six Japanese populations ofH. trifoliiwere in congruence with those of previous descriptions of this species from Germany, Italy, Japan, New Zealand, Russia, The Netherlands, UK and USA. The results of the phylogenetic analyses of the D2-D3 expansion segments of 28S rRNA gene and theCOImtDNA gene sequences discriminatedH. trifoliifrom most of the other closely related species of theSchachtiigroup. The intraspecific sequence differences in theSchachtiigroup were much higher inCOIthan in D2-D3. TheH. trifoliipopulations displayed very low levels of intraspecific variations (up to 0.3%) in theCOImtDNA gene sequences. The phylogenetic relationships ofH. trifoliiwith otherHeteroderaspecies, as inferred from the analyses of the ITS rRNA gene, D2-D3 of 28S rRNA gene andCOImtDNA gene sequences, were determined. more...

A new cyst nematode, herein described as Globodera sandveldensis n. sp., was found in the Sandveld, Western Cape Province, South Africa. As the host plant of G. sandveldensis n. sp. is currently unknown, the species is represented by cysts and second-stage juveniles (J2) only. The J2 are characterised by a well developed stylet of 26.4 (24.8-28.5) μm with rounded to anteriorly flattened knobs. The distance from the dorsal pharyngeal gland outlet to the stylet knobs is 4.5 (2.4-7.2) μm. The tail is 64 (56-77) μm long and the length of the hyaline region is 33 (22-39) μm. The cysts are characterised by their ovate to spherical shape, short neck, and the presence of subcuticular punctations and bullae or vulval bodies. Six to 14 cuticular ridges/lines are present on the outer surface of the cyst between the anus and vulval basin. Granek’s ratio is 1.7 (0.9-3.0), the vulval basin diam. is 20.4 (13.1-34.6) μm and the distance between vulval basin and anus is 33.5 (19.7-54.0) μm. Phylogenetic relationships with other species of the genus, inferred from ITS-rDNA sequences, indicate that G. sandveldensis n. sp. is included in the clade of Globodera sp. that parasitise non-solanaceous plants and is closely related to unidentified Globodera spp. from Portugal, G. millefolii, and G. artemisiae. more...

The Korean cyst nematode, Heterodera koreana, was recorded for the first time from Japan and characterised morphologically, morphometrically and molecularly. In total, 41 populations were detected from soil samples collected from the rhizosphere of four bamboo species in Japan: 31 populations from moso bamboo (Phyllostachys edulis), seven from madake (P. bambusoides), two from henon bamboo (P. nigra var. henonis) and one from fish pole bamboo (P. aurea). The morphology and morphometrics of the Japanese population were in agreement with those of the original description of H. koreana from South Korea and other subsequent descriptions from China and Iran, with the exception of some minor differences. The results of the phylogenetic analyses of the D2-D3 expansion segments of 28S rRNA gene and ITS rRNA gene sequences confirmed the species identification and phylogenetic relationship of H. koreana with other Heterodera species. The COI mtDNA gene sequences were obtained for the first time for H. koreana. Three COI haplotypes found in Japanese H. koreana populations showed a characteristic geographical distribution in Japan. more...

Biocontrol efficacy of Myrothecium roridum against the southern root-knot nematode, Meloidogyne incognita , was evaluated in pot experiments on tomato. When treated with the culture filtrate of M. roridum , egg hatching was significantly reduced. Inhibition rate of egg hatching was dose dependent, which increased with the increment of concentration of culture filtrate. Three days after treatment the highest rate of 78.9% was observed with 10 mL of original culture filtrate of M. roridum . The number of root galls was reduced with the treatment of the culture filtrate. Significant difference was observed between treatment and non-treatment. However, biocontrol efficacy was not dose-dependent, ranging from 67.5% to 74.3%. M. roridum caused inhibition of mobility of second-stage juveniles of M. incognita at all concentrations tested. The rate showed positive correlation with concentrations of the culture filtrate, showing the highest rate of 82.6% in 4% of the culture filtrate. more...

In Portugal, growing potatoes (Solanum tuberosum) has both social and economic importance. Because potato cyst nematodes (PCN) are major pests of potatoes, their presence in these areas could pose a risk to its production. Therefore, the National Survey Plan for PCN that was implemented in 2010 is still ongoing. This survey aims for the early detection of PCN to provide tools to control and manage initial PCN infestations below the damage threshold level, while avoiding their dispersal within both national and EU territories. During the 2018 National Survey in the potato production areas of the Sao Miguel Island (Azores), six bulk soil samples of 1 kg from a small field cultivated for household consumption in Nordeste County were investigated. A subsample of 500 g from the bulk sample was dried, and cysts were extracted using a Fenwick can. Dried cysts were hydrated and cut to release eggs, and hatched J2 were collected for morphometric analysis. The identification of PCN was based on a combination of n = 30 cysts and n = 90 J2 measurements. The cyst length excluding neck (L) was 493.658 ± 89.377 μm, width (W) was 474.090 ± 93.569 μm, the L/W ratio was 1.051 ± 0.115, and neck was 110.894 ± 26.353 μm. The number of cuticular ridges between the vulva and the anus was higher than 20. The distance from vulva to anus was 60.15 ± 6.7 µm with the Granek’s ratio ranging from 1.26 to 4.99. The vulva fenestrate was 25.13 ± 6.7 µm in diameter and anus visible in almost all specimens, with a V-shaped mark. The stylet length of J2 was 23.14 ± 1.8 µm with rounded knobs. Body length was 449.79 ± 30.3 µm, and average true and hyaline tail length were 50.92 ± 6.4 µm and 26.50 ± 4.3 µm, respectively. The overall morphometric values were within the range described in PM 7/40(4) (EPPO 2017) for Globodera rostochiensis. The above morphological characterization was also confirmed using a sequence-specific multiplex PCR (Bulman and Marshall 1997) described in PM7/40(4) (EPPO 2017) and conventional PCR of 18S rDNA (SSU), 28S rDNA (LSU), and cytochrome oxidase subunit I (COI) as described in PM7/129(1) (EPPO 2016). The nucleotide sequences (MN226947, MN238768, and MK798162) showed a similarity of 99 to 100% with available isolates of G. rostochiensis in NCBI database. A pathogenicity test was carried out in the greenhouse by planting tubers of the susceptible cultivar Desiree in four plastic pots of 15 cm diameter. Pots were inoculated with an initial population density of 5 J2 and eggs per gram of soil and harvested after 90 days. A final population (Pf) of mean of x¯ = 23.3 J2 or eggs per gram of soil was obtained, resulting in a reproduction factor (R=Pf/Pᵢ) of 4.66 ± 0.86. According to the European Commission Regulation EC 690/2008 updated by implementing regulation EU 2016/873, the Azores islands are recognized as protected zones for G. rostochiensis and G. pallida. This is the first report of the presence of G. rostochiensis in the Azores islands. Research will focus more on the spatial distribution of the nematodes, and based upon it integrated control methods will be devised including strict phytosanitary measures to prevent spread and ensure further the Azores as a PCN protected zone. more...

A new species of cyst nematode, Cactodera chenopodiae n. sp., parasitizing common lambsquarter, Chenopodium album L., is described from native vegetation in Liaoning, China. Cactodera chenopodiae n. sp. has a circumfenestrate pattern typical of the genus and is morphologically similar to C. cacti Krall & Krall, 1978. However, in the new species, females and cysts show a larger L/W ratio whereas second-stage juveniles (J2s) have a longer hyaline region. The new species is also morphologically similar to C. milleri Graney & Bird, 1990, but the J2s differ by a larger b ratio and longer tail. Based on DNA sequences of the 28S and ITS rRNA, C. chenopodiae n. sp. comes close to C. estonica Krall & Krall, 1978, although it is distinct from the latter with respect to the presence of a punctate eggshell and larger b ratio in the J2s. Although morphometric comparisons with additional Cactodera species show the overlapping of diagnostic morphological characters, our phylogenetic analyses based on both rRNA genes support C. chenopodiae n. sp. as a unique lineage. more...

Heterodera schachtii, the sugar beet cyst nematode, is a major pest of agricultural crops worldwide. We report the development of fifteen polymorphic microsatellite markers and assess the genetic diversity and structure of three populations following a recent invasion of a previously unaffected region. Populations had low levels of heterozygosity, likely indicative of population structure, history, and inbreeding. Genetic diversity analysis suggested that the current infestation in South Korea may have come either from a single source population of mixed ancestry, or from multiple sources, indicating that implementing adequate prevention measures is still an unmet challenge. Much more work is needed on this species to identify global patterns of spread, and the microsatellite loci we develop here should be useful in many regions for modeling range expansion, studying the evolution of resistance, and increasing the effectiveness of pest management strategies. more...

Published data on the presence or absence of phasmids in males of Heteroderidae species are compiled and critically reviewed. Based mainly on results of previous SEM studies and complemented by light microscopy using DIC optics, the conclusion is drawn that male phasmids appear to be absent in all species of the genera assigned to the subfamilies Heteroderinae and Ataloderinae, but present and often distinct in the Meloidoderinae genera Cryphodera and Meloidodera. The presence of male phasmids is considered as ancestral, and loss of phasmids as a derived character. more...

Purpose. Analysis of domestic and foreign literature on the role of alternative weed hosts of phytonematode families Heteroderidae and Meloidogynidae. Results. The nematodes of the Heteroderidae family can be hosted by 350 species of weeds from 40 families and 155 genera. Most of these weeds belong to five families: Chenopodiaceae (37 species from three genera), Solanaceae (44 species from 6 genera), Poaceae (47 species from 24 genera), Brassicaceae (67 species from 29 genera) and Fabaceae (85 species out of 25 genera) and have a total of 280 species of 87 genera. Weeds belonging to the families Lathurus (13 species), Vicia (15 species), Chenopodium (14 species) and Solanum (30 species) generally comprise 72 nematode host species. All other genera have fewer than 10 species of weed hosts. Nematodes of the Meloidogynidae family can be hosted by 994 weed species from 118 families and 487 genera. The greatest number of weeds that host parasitic nematodes belong to five families: Fabaceae (308 species), Asteraceae (267 species), Poaceae (8 species), Solanaceae (155 species) and Amaranthaceae (89) and among the families Solanum (61 species), Amaranthus (40 species), Trifolium (36 species), Nicotiana (30 species), Chenopodium and Euphorbia (each 28 species). Conclusions . In order to develop a joint strategy of effective protection of crops from weeds and parasitic nematode species, the biological and ecological characteristics of these harmful organisms should be thoroughly studied and the factors that would reduce their negative impact on plants and prevent crop losses to establish should be found. more...

The root-knot nematode, Meloidogyne incognita Kofoid and White (Tylenchida: Heteroderidae), is one of the most important plant parasitic nematodes attacking many plant roots. In this paper, the predation and biocontrol efficiency of Blattisocius dolichus Ma (Acari: Blattisociidae) on this nematode were studied. The predation rate and the environmental factors affecting predation rate of B. dolichus on second-stage juveniles of M. incognita (Mi-J2) were studied in experimental arenas in plastic dishes. Both female and male mites had greater capability in consuming Mi-J2, and daily predation rate of female and male mites was not less than 35 and 29.6 nematodes within seven days, respectively. Temperature, nematode density and starvation affected B. dolichus predating on Mi-J2, and when offered 300 nematodes per dish, the predation rate of mites starved for 96 h was the highest at 25 °C, with female and male mites consumed 50.5 and 54 nematodes in 24 h, respectively. The biocontrol of B. dolichus against M. incognita was carried out on potted water spinach Ipomoea aquatic in a greenhouse. The water spinach roots were inoculated with 1,000 Mi-J2 ten days after releasing 100, 200, 300, 400 and 500 mites per pot. Compared to the nematodes–alone control, the number of root-knots of all mite treatments and the number of egg masses of the treatments with 300, 400 and 500 mites significantly decreased. Effect of releasing 500 mites on control of the root nematode M. incognita was best among all mite treatments, reduced the root-knots and egg masses 37.1 and 55.1 %, respectively, but no significant difference was observed compared to 400 mites treatment. more...

A new non-cyst forming nematode, Cryphodera gayae n. sp., was found from the root of crapemyrtle (Lagerstroemia indica) in Korea. Female C. gayae n. sp. appears pearly white when young, has protruding vulval lips, flat to concave anus-vulva profile and has three lateral lines in J2s. Morphologically, Cryphodera gayae n. sp. is most similar to C. brinkmani but differ by the tail shape of J2 (sharply pointing with constriction at the middle of hyaline without mucro tip vs. sharply pointing with mucro-like tip), shorter stylet length of J2 (26.8–31.3 µm vs 31.6–35.4 µm), stylet knob shape of J2 (flat posteriorly vs concave), number of eggs in female (64–69 vs 15–45). C. gayae n. sp. differs from C. kalesari by the longer vulva-anus distance (51.9–54.1 µm vs 35 µm), the bigger body size of female (363.1–544.6 µm vs 272–353 µm in length), in J2, the longer tail length (59.6–76.7 µm vs 27–54 µm), longer hyaline length (31.7–47.8 µm vs 18–26 µm) and the shape of tail (sharply pointing with constriction at the middle of hyaline vs narrow rounded without constriction). From C. sinensis, the new species differs by the longer J2 tail length (59.6–76.7 µm vs 52.0–65.0 µm) and longer hyaline portion (31.7–47.8 µm vs 24.5–35.0 µm) of J2. C. gayae n. sp. and can be distinguished from the remaining four species, C. eucalypti, C. podocarpi, C. nothophagi and C. coxi, by the shape of the J2 tail terminus (sharply pointing tip with constriction at the middle of hyaline vs narrow rounded) and the shape of the vulval lips (pronounced protruding vs protruding slightly out of body contour). Molecular analysis shows that C. gayae n. sp. is the most similar to C. sinensis with the identity of sequence 95% on the rRNA LSU D2–D3 segments and the highest match with C. brinkmaini with 88% identity on the ITS region. more...

In this work, we report results of molecular and morphological analyses of a potato field population of Globodera (Nematoda: Heteroderidae) species, in Slovakia. Unexpectedly, our data show a mixed occurrence of two potato cyst nematode species, Globodera rostochiensis and G. pallida, in this locality. To our knowledge, this is the first report of mixed occurrence of these economically important plant-parasitic species in the same locality in the Central Europe. In addition, this finding reinforces the possibility of the cross-hybridization between these two nematode species that might result in a generation of new genotypes. more...

A new species of cyst nematode, Cactodera torreyanae sp. n., parasitising romerito plants, Suaeda torreyana (Chenopodiaceae), found in highly saline soils in Texcoco, Mexico, is described. The new species is morphologically and molecularly related to C. weissi, from which it differs in smaller fenestral diam., longer body and shorter tail lengths of second-stage juveniles (J2) and to C. rosae, from which it differs in smaller cyst size, longer body length of J2 and the presence of a smooth eggshell surface. Phylogenetic relationships within populations and species of the Punctoderinae and Cactodera are given based on the analysis of the D2-D3 expansion segments of 28S rRNA and the ITS rRNA gene sequences. more...

Cryphodera sinensis n. sp. is described from ramie (Boehmeria nivea) based on the morphology and molecular analyses of rRNA small subunit (SSU), D2D3 expansion domains of large subunit (LSU D2D3) and internal transcribed spacer (ITS). This new species is characterized by oval females with a distinct subcrystalline layer and pronounced and protruding vulval lip, distinctly concave vulva–anus profile and a vulva–anus distance of 29.5–35.8 μm. Males possess two annuli in the lip region, a stylet 27–32.5 μm in length with round knobs sloping slightly posteriorly, lateral fields with three lines, spicules 20–28 μm long and the presence of a short cloacal tube. Second-stage juveniles possess three lip annuli, a stylet 28–31 μm in length with well-developed knobs projected anteriorly and three lines along the lateral field. The pointed tail, 52–65 μm long, possesses a mucro-like tip and a hyaline region, 24.5–35 μm long. Large phasmids with a lens-like structure are located 2–6 annuli posterior to the anus. Phylogenetic analysis shows that the species has unique SSU, LSU D2D3 and ITS rRNA sequences. Phylogenetic relationships of the three rDNA sequences of C. sinensis n. sp. and other cystoid/cyst nematodes are analysed together with a comparison of other species within the genus Cryphodera. more...

This article provides morphological and molecular characteristics of Punctodera stonei Brzeski, 1998. Comparison of partial sequences of 18S and 28S rDNA genes from P. stonei sampled in Poland and Punctodera sp. from Canada showed their 100% similarity. This is the first report on the occurrence of P. stonei outside of Europe. We provide data on morphology of males and 2nd stage juveniles of this species and an identification key to males of the genus Punctodera Mulvey et Stone, 1976. Moreover, the paper presents evolutionary relationships of P. stonei within the family Heteroderidae. more...