Journal articles on the topic 'Pratylenchus neglectus'
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1
TOWNSHEND, J. L. "POPULATION DENSITIES OF FOUR SPECIES OF ROOT-LESION NEMATODES (Pratylenchus) IN THE OAT CULTIVARS, SAIA AND OAC WOODSTOCK." Canadian Journal of Plant Science 69, no. 3 (July 1, 1989): 903–5. http://dx.doi.org/10.4141/cjps89-105.
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The population densities of four species of root-lesion nematodes (Pratylenchus) were examined in two cultivars of oat (Avena sativa L.) grown in greenhouse pots. The cultivar Saia harbored fewer P. neglectus and P. penetrans than the cultivar OAC Woodstock, while both cultivars were similar hosts for P. sensillatus. Pratylenchus crenatus did not develop in either cultivar.Key words: Oat, population density, Pratylenchus crenatus, Pratylenchus neglectus, Pratylenchus penetrans, Pratylenchus sensillatus
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Smiley, Richard W., Guiping Yan, and Jennifer A. Gourlie. "Selected Pacific Northwest Rangeland and Weed Plants as Hosts of Pratylenchus neglectus and P. thornei." Plant Disease 98, no. 10 (October 2014): 1333–40. http://dx.doi.org/10.1094/pdis-12-13-1295-re.
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Eighteen rangeland plants and 16 weed species were assayed in the greenhouse for efficiency as hosts of Pratylenchus neglectus and P. thornei. Hosting ability ratings were assigned using the ratio of final versus initial nematode density and by comparing the final nematode density to that of susceptible wheat controls. Good hosts of both Pratylenchus spp. included thickspike bluegrass ‘Critana’, smooth brome ‘Manchar’, seven wheatgrasses, and jointed goatgrass. Good hosts of P. neglectus but not P. thornei included two hairy vetches, western wheatgrass ‘Rosana’, big bluegrass ‘Sherman’, tall wheatgrass ‘Alkar’, green foxtail, kochia, large crabgrass, palmer amaranth, redroot pigweed, tumble mustard, and wild oat. Good hosts of P. thornei but not P. neglectus included hard fescue ‘Durar’, sheep fescue ‘Blacksheep’, downy brome, and rattail fescue. Poor or minor hosts of both Pratylenchus spp. included two alfalfas, dandelion, horseweed, lambsquarters, prostrate spurge, and Russian thistle. These assays will provide guidance for transitioning rangeland into crop production and for understanding the role of weeds on densities of Pratylenchus spp. in wheat-production systems.
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Timper, P., and B. B. Brodie. "First Report of Pratylenchus neglectus in New York." Plant Disease 81, no. 2 (February 1997): 228. http://dx.doi.org/10.1094/pdis.1997.81.2.228c.
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Soil samples were collected from a field in Wyoming County near Portageville, NY, on 29 October 1992 and 23 November 1993. The field was planted with winter wheat (Triticum aestivum L.) from September 1991 to August 1992, and with potato (Solanum tuberosum L.) cv. Superior from May 1993 to September 1993. Thirty-nine and 45 samples were collected along three transects in 1992 and 1993, respectively. Two species of Pratylenchus were identified, P. neglectus (Rensch) Filipjev & Sch. Stek. (identification confirmed by A. M. Golden) and P. penetrans (Cobb) Filipjev & Sch. Stek. Their combined population densities were 134 ± 18 (mean ± SE per 100 cm3 soil) in 1992 and 195 ± 12 in 1993. P. neglectus was found in all samples, whereas P. penetrans was found in 33 and 78% of the samples in 1992 and 1993, respectively. Where both species occurred together, the density of P. neglectus was 7 to 8 times that of P. penetrans. In both years, spores of a nematode-pathogenic bacterium (probably a Pasteuria sp.) were found attached to the cuticle of P. penetrans (68% with spores in 1993) but were rarely attached to P. neglectus (less than 1% with spores). Although both Pratylenchus spp. are widespread in North America, this is the first report of P. neglectus in New York. Its dominance in the field was unexpected because P. penetrans and P. crenatus Loof are typically the dominant Pratylenchus spp. in potato production regions of northeastern North America (1). The presence of the bacterium, which appeared to be host-specific for P. penetrans, may help explain the dominance of P. neglectus. Reference: (1) R. N. Huettel et al. Am. Potato J. 68:345, 1991.
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Smiley, Richard W., Guiping Yan, and Jennifer A. Gourlie. "Selected Pacific Northwest Crops as Hosts of Pratylenchus neglectus and P. thornei." Plant Disease 98, no. 10 (October 2014): 1341–48. http://dx.doi.org/10.1094/pdis-12-13-1296-re.
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Thirty crop species and cultivars were assayed in the greenhouse for efficiency as hosts of Pratylenchus neglectus and P. thornei. Hosting ability ratings were assigned using the ratio of final versus initial nematode density and also by comparing the final nematode density to that of a susceptible wheat control. Good hosts of both Pratylenchus spp. included oat ‘Monida’, chickpea ‘Myles’, and lentil ‘Athena’ and ‘Morton’. Good hosts of P. neglectus but not of P. thornei included 10 Brassica spp. (5 canola, 2 mustard, and 3 camelina cultivars), chickpea ‘Sierra’, sudangrass ‘Piper’, and sorghum/sudangrass hybrid ‘Greentreat Plus’. Good hosts of P. thornei but not of P. neglectus included lentil ‘Skyline’ and pea ‘Granger’, ‘Journey’, and ‘Universal’. Poor or minor hosts of both Pratylenchus spp. included chickpea ‘Dwelley’, pea ‘Badminton’, safflower ‘Gila’, ‘Girard’, and ‘KN 144’, sunflower ‘2PD08’, flax ‘Pembina’, eastern gamagrass ‘Pete’, and switchgrass ‘Blackwell’. Results of these assays will provide guidance for improving crop rotation and cultivar selection efficiencies.
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Olthof, Th H. A., and M. S. Wolynetz. "Pratylenchus penetrans and P. neglectus in tubers of potato (Solanum tuberosum) in Ontario." Canadian Journal of Plant Science 71, no. 4 (October 1, 1991): 1251–56. http://dx.doi.org/10.4141/cjps91-173.
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Root-lesion nematodes (Pratylenchus penetrans) were extracted from peels of potato tubers (Solanum tuberosum 'Russet Burbank'). The average number of P. penetrans recovered over a 2-wk period in a mist chamber from four batches of tubers, stored for 3–18 wk at 7 °C in a cold room, ranged from 11 to 1925 nematodes tuber−1. An average of 374 Pratylenchus neglectus tuber−1 were recovered from the peels of potato Norchip, grown in soil containing on average 4370 nematodes kg−1 of soil at harvest, and stored for 19 wk at 7 °C. P. penetrans and P. neglectus were recovered only from the outer layer of potato tubers; none was found in the inner core. Planting halves of tubers containing an average of 1925 P. penetrans tuber−1 into nematode-free soil resulted in soil population densities of 2225 P. penetrans kg−1 of soil and root population densities of 884 nematodes root system−1 after 8 wk in the greenhouse. Although many, if not most, potato fields in southern Ontario are already infested by P. penetrans, these studies have shown that stored, infested tubers can initiate a new infestation. Key words: Peel, potato tuber, Pratylenchus neglectus, Pratylenchus penetrans, root-lesion nematode, Solanum tuberosum
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Majd Taheri, Zahra, Zahra Majd Taheri, Zahra Tanha Maafi, Zahra Majd Taheri, Zahra Tanha Maafi, Sergei A. Subbotin, Zahra Majd Taheri, et al. "Molecular and phylogenetic studies on Pratylenchidae from Iran with additional data on Pratylenchus delattrei, Pratylenchoides alkani and two unknown species of Hirschmanniella and Pratylenchus." Nematology 15, no. 6 (2013): 633–51. http://dx.doi.org/10.1163/15685411-00002707.
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Thirteen species of Pratylenchidae: Pratylenchus coffeae, P. delattrei, P. loosi, P. neglectus, P. penetrans, P. pseudopratensis, P. thornei, P. vulnus, Pratylenchus sp., Pratylenchoides alkani, P. ritteri, Hirschmanniella sp. and Zygotylenchus guevarai were collected from different crops and plants throughout Iran. The specimens were identified using morphological and molecular methods. Morphometrics and morphology are given for Pratylenchus sp., P. delattrei, Pratylenchoides alkani and Hirschmanniella sp. The D2-D3 expansion segments of the 28S rRNA gene were amplified and sequenced for all 13 species studied. Diagnostic PCR-ITS-RFLP profiles are given for Pratylenchus delattrei, P. penetrans, P. pseudopratensis, Pratylenchus sp., Pratylenchoides alkani and P. ritteri. Pratylenchus neglectus and P. thornei, collected from cereal fields, P. loosi from tea plantations, P. coffeae from banana, P. penetrans from ornamental plants, P. vulnus from pines and Z. guevarai from almonds showed a high level of similarity in the D2-D3 sequences with corresponding GenBank sequences. Nucleotide differences between Iranian populations and reference species were in the intraspecific range. Pratylenchus delattrei, found in vegetable fields, and Pratylenchus sp. from palm rhizosphere, formed a highly supported clade with P. zeae, the two former species being morphologically very close to the latter except in tail shape. Pratylenchus pseudopratensis, from cereal fields, clustered with P. vulnus with low support. Phylogenetic relationships within Pratylenchus species were mainly congruent with those obtained in previous studies. Despite the morphological similarities between P. ritteri and P. alkani, the D2-D3 of 28S rRNA gene sequences differed by 5 bp. Hirschmanniella sp., from a rice field, formed a clade with H. loofi and H. kwazuna.
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Smiley, Richard W., and Stephen Machado. "Pratylenchus neglectus Reduces Yield of Winter Wheat in Dryland Cropping Systems." Plant Disease 93, no. 3 (March 2009): 263–71. http://dx.doi.org/10.1094/pdis-93-3-0263.
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Wheat (Triticum aestivum) in low-precipitation regions of eastern Oregon and Washington is grown mostly as rainfed biennial winter wheat (10-month growing season) planted into cultivated fallow (14-month crop-free period). There are increasing trends for cultivated fallow to be replaced by chemical fallow and for spring cereals to be planted annually without tillage. Most fields are infested by the root-lesion nematodes Pratylenchus neglectus or P. thornei. A replicated multiyear experiment was conducted to compare cropping systems on soil infested by P. neglectus. Populations became greater with increasing frequency of the host crops mustard, pea, and wheat. Annual winter wheat had the highest P. neglectus populations, the lowest capacity to extract soil water, and a lower grain yield compared with wheat grown biennially or rotated with other crops. Populations of P. neglectus did not differ for cultivated versus chemical fallow. Lowest populations occurred in annual spring barley. Winter wheat yield was inversely correlated with the population of P. neglectus. Measures to monitor and to reduce the population of P. neglectus in Pacific Northwest wheat fields are recommended.
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Al-Khafaji, Riyadh T., Erin E. Gunnink Troth, Kris N. Lambert, Jeffrey A. Johnston, and Alan T. Dyer. "Pathotypes Detected Among Populations of Pratylenchus neglectus Collected From Montana." Plant Disease 103, no. 12 (December 2019): 3259–64. http://dx.doi.org/10.1094/pdis-12-18-2234-re.
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The root lesion nematode, Pratylenchus neglectus, is one of the most damaging nematodes to affect wheat worldwide. The nematode is widely distributed in Montana, primarily affecting winter wheat within the state. Managing the nematode primarily involves rotation to resistant and moderately resistant crops (peas, lentils, and barley). A nematode survey was conducted across the state nearly 10 years after an initial survey, to reassess the nematode threat and assess the impact of changing trends in crop rotations. To assess the broad applicability of rotation crops to control P. neglectus across Montana, greenhouse trials were conducted to challenge rotational crops using eight populations of P. neglectus collected from geographically diverse locations across the state. In the trials, conducted with four Montana crops, a significant interaction was detected between crop and nematode population (analysis of variance P < 0.001). Populations from Hill, Dawson, and Chouteau counties were found to be pathogenic on barley. Male nematodes were detected in seven of the eight pot culture populations, and these were confirmed to be P. neglectus by morphological and molecular methods. These results suggest a re-evaluation of barley and lentils as a management option for P. neglectus in Montana, as pathotypes for each exist within the state.
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Kumari, S. "Characterization of Pratylenchus crenatus and P. neglectus (Nematoda: Pratylenchidae) associated with wheat crop." Helminthologia 52, no. 3 (September 1, 2015): 280–86. http://dx.doi.org/10.1515/helmin-2015-0043.
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Abstract The distribution of Pratylenchus species associated with wheat crops was investigated in Bohemian region of the Czech Republic. In total twelve localities were sampled. The populations were identified based on morphology and morphometrics, and further characterised based on sequences of the rDNA D2/D3 region and 18S gene. Pratylenchus crenatus was present in two localities and P. neglectus in five localities. At one locality both species were detected. Sequence analysis of 18S and D2/D3 region of three populations of P. crenatus reveal no variation while five populations of P. neglectus differ by 0 to 0.14 % (18S) and 0.17 to 0.50 % (D2/D3).
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Elhady, Ahmed, Torsten Thünen, Frank Höppner, Christiane Balko, Holger Heuer, and Johannes Hallmann. "Evaluation of soybean cultivars for their susceptibility to root-lesion nematodes under temperate conditions." Nematology 21, no. 5 (2019): 523–31. http://dx.doi.org/10.1163/15685411-00003232.
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Summary Soybean, Glycine max, is a relatively new crop in Europe gaining increasing interest for its potential to fix atmospheric nitrogen and thus increase sustainability of modern agricultural production systems. Under temperate conditions, root-lesion nematodes (Pratylenchus spp.) are one of the most prominent plant-parasitic nematode taxa of economic concern in soybean. Here, we investigated the susceptibility of soybean cultivars towards naturally occurring populations of Pratylenchus spp. and their effects on soybean yield. At the site Bundesallee the cultivars ‘Abelina’, ‘Primus’ and ‘Taifun3’ supported the highest infestation and multiplication of a mixed population of P. neglectus and P. crenatus, while ‘Sultana’ and ‘Solena’ were least susceptible. At the field site Groß Lüsewitz, ‘Primus’ and ‘Merlin’ cultivars were significantly more susceptible to P. neglectus than ‘Sultana’. Soybean yield was reduced by high initial densities of Pratylenchus spp. Results are expected to contribute to a better nematode management.
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Smiley, Richard W., Ruth G. Whittaker, Jennifer A. Gourlie, and Sandra A. Easley. "Suppression of Wheat Growth and Yield by Pratylenchus neglectus in the Pacific Northwest." Plant Disease 89, no. 9 (September 2005): 958–68. http://dx.doi.org/10.1094/pd-89-0958.
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Many wheat (Triticum aestivum) fields planted annually in the Pacific Northwest are infested by high populations of the lesion nematode, Pratylenchus neglectus. Spring wheat cultivars varying in tolerance and resistance to P. neglectus were treated or not treated with aldicarb to examine relationships between the nematode and growth and yield of annual direct-seeded (no-till) wheat. Increasing initial density of P. neglectus in soil was more strongly associated with declining growth and yield of intolerant (Machete and Spear) than moderately tolerant (Frame and Krichauff) cultivars. Yield suppression by P. neglectus was generally 8 to 36% for intolerant cultivars, but reached 71% in soil also harboring Heterodera avenae, Rhizoctonia solani AG-8, and Gaeumannomyces graminis var. tritici. Intolerant cultivars had lower yields than Krichauff in rainfed but not in irrigated experiments. Density of P. neglectus in mature roots was generally lower for moderately resistant Krichauff than for susceptible Machete and Spear. Aldicarb improved yields in irrigated but not in rainfed experiments, and increased plant height and reduced variability in tiller height, canopy temperature, and density of P. neglectus in roots. This is the first report of damage to wheat by P. neglectus in the Pacific Northwest. Breeding wheat for tolerance and resistance to P. neglectus is suggested.
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Oliveira, Claudio M. G., Vivian Blok, Roy Neilson, Tomasz Mróz, and David Roberts. "Hydrolysis probe-based PCR for detection of Pratylenchus crenatus, P. neglectus and P. penetrans." Nematology 19, no. 1 (2017): 81–91. http://dx.doi.org/10.1163/15685411-00003033.
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Molecular detection of pest and pathogens relies on rapid and dependable methods for their identification as well as an assessment of their abundance. This study describes the development and evaluation of a diagnostic method for detection of Pratylenchus crenatus, P. penetrans and P. neglectus, based on a hydrolysis probe qPCR assay. Primer/probe sets were designed targeting the ITS-1 rDNA. In order to assess the specificity, primer/probe sets were tested with samples of non-target Pratylenchus species and Radopholus similis. Experiments using dilutions of purified plasmid standards tested the sensitivity of the hydrolysis assay against detection of DNA extracted from individual nematodes. Target DNA was detected in soil samples collected from potato fields and this indicated that P. crenatus, P. neglectus and P. penetrans are widely distributed in Scotland, frequently co-existing in mixed populations, with P. crenatus more prevalent than either P. neglectus or P. penetrans.
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May, David B., Wendy A. Johnson, Peter C. Zuck, Chengci C. Chen, and Alan T. Dyer. "Assessment and Management of Root Lesion Nematodes in Montana Wheat Production." Plant Disease 100, no. 10 (October 2016): 2069–79. http://dx.doi.org/10.1094/pdis-02-16-0176-re.
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Root lesion nematodes (Pratylenchus spp.) hinder dryland wheat production worldwide. Montana, a leading U.S. wheat production region, has climatic conditions favorable for Pratylenchus spp. A 2006-2007 statewide soil survey revealed damaging populations of Pratylenchus neglectus, primarily in winter wheat production areas of Montana, whereas P. thornei was not found. Analyses of wheat yields in infested fields revealed negative correlations between yields and spring nematode populations (all P < 0.05 and all R2 > 0.2). Statewide yield losses due to root lesion nematodes were an estimated 12 and 15% for winter wheat in 2006 and 2007, respectively. A subsequent study conducted in 2008 to 2009 revealed significant differences in reproductive success of P. neglectus among seven rotation treatments (P < 0.001). Nematode populations persisted from spring to fall under fallow, barley, pea, and camelina; increased under winter wheat and canola; and decreased under lentil. Populations were sustained through winter following winter wheat and barley but declined following canola, camelina, pea, lentil, and fallow. A screening of 19 barley lines for resistance to P. neglectus revealed significant variation in resistance among entries (P < 0.001), with ‘Harrington’ barley displaying promising levels of resistance. Development of resistant wheat cultivars remains a principal goal in managing this nematode.
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Gray, Michael, Horacio Lopez-Nicora, Tesfamariam Mekete, Terry Niblack, and Kimberly Reynolds. "Distribution and diversity of root-lession nematode (Pratylenchus spp.) associated with Miscanthus × giganteus and Panicum virgatum used for biofuels, and species identification in a multiplex polymerase chain reaction." Nematology 13, no. 6 (2011): 673–86. http://dx.doi.org/10.1163/138855410x538153.
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AbstractThe distribution of Pratylenchus spp. from bioenergy field plots in six states (Illinois, Iowa, South Dakota, Kentucky, Tennessee, Georgia) of the USA were surveyed. The species were identified based on morphology and morphometrics and further characterised based on fragment sequences of the 28S rRNA of the D2-D3 region. The region revealed variations in sequencing information that supports the morphological identification. In this work, six Pratylenchus spp. were detected: Pratylenchus brachyurus, P. crenatus, P. hexincisus, P. neglectus, P. penetrans and P. scribneri. Pratylenchus scribneri, P. crenatus, and P. penetrans were distributed most widely, with detection of 34, 29 and 15%, respectively. Pratylenchus hexincisus, P. brachyurus and P. neglectus were distributed sporadically, with detection rates of 10.0, 2.6 and 2.0%, respectively. A one-step multiplex PCR was developed for the simultaneous detection of P. scribneri, P. crenatus and P. penetrans. Sequence data from this research and NCBI were used to generate different primer sets that are species-specific. We have therefore designed three sets of primers that discriminate P. scribneri, P. crenatus and P. penetrans in multiplex PCR. All the tested primers have shown specificity and have no cross-reaction with the non-target species. When used in a uniplex, duplex and triplex PCR, the selected three primers gave a unique electrophoretic DNA banding pattern characterised by a single DNA fragment for P. scribneri (ca 750), P. crenatus (ca 690), and P. penetrans (ca 520). The method could be used for routine diagnostic programmes.
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Nuaima, Rasha Haj. "The Difference in the Bacterial Attachment among Pratylenchus neglectus Populations and Its Effect on the Nematode Infection." Microorganisms 10, no. 8 (July 27, 2022): 1524. http://dx.doi.org/10.3390/microorganisms10081524.
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Different bacterial isolates attach to the cuticle of plant-parasitic nematodes, affecting their interactions with the host plant. Nematode populations differ in their genetic and cuticle structures, causing variable interactions with host plants and natural enemies. In the current study, attachment assays were carried out to compare the attachment of soil bacteria in general and the bacterial isolate of Rothia sp. in particular among geographically diverse populations of Pratylenchus neglectus. Biological and molecular assays were further conducted to examine the effect of Rothia attachment on nematode penetration into barley roots and to sequence the fatty acid- and retinol-binding gene (Pn-far-1). The results showed that nematode populations of P. neglectus differed in their bacterial attachment. Soil bacteria and Rothia sp. attached specifically to the cuticle of P. neglectus and did so differently among the nematode populations. Rothia attachment caused a reduction in the infectivity of three nematode populations in barley roots. The sequencing of the far-1 gene revealed genetic variability within and among P. neglectus populations. In conclusion, the interaction between P. neglectus and their bacterial attachers occurs in a population-specific manner, elucidating an essential aspect of using biological agents to manage plant-parasitic nematodes. Key Message: 1. Geographically diverse populations of the root lesion nematode Pratylenchus neglectus differed in the soil bacterial communities attached to their cuticles. 2. The bacterial isolate of Rothia sp. attached to the cuticle of P. neglectus and reduced its penetration into the host plant in a population-specific manner. 3. The fatty acid- and retinol-binding gene (far-1) varied within and among P. neglectus populations with their different bacterial attachment.
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Yan, Guiping, Richard W. Smiley, Patricia A. Okubara, Andrea M. Skantar, and Catherine L. Reardon. "Developing a Real-Time PCR Assay for Detection and Quantification of Pratylenchus neglectus in Soil." Plant Disease 97, no. 6 (June 2013): 757–64. http://dx.doi.org/10.1094/pdis-08-12-0729-re.
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Pratylenchus neglectus is one of the most widespread and economically important nematodes that invades plant roots and restricts wheat productivity in the Pacific Northwest. It is challenging to quantify P. neglectus using microscopic methods for studies that require large-scale sampling, such as assessment of rotation crops, wheat cultivars, and other management practices. A real-time quantitative polymerase chain reaction (qPCR) assay was developed to detect and quantify P. neglectus from DNA extracts of soil. The primers, designed from the internal transcribed spacer region of rDNA, showed high specificity with a single melt curve peak to DNA from eight isolates of P. neglectus but did not amplify DNA from 28 isolates of other plant-parasitic and non-plant-parasitic nematodes. A standard curve (R2 = 0.96; P < 0.001) was generated by amplifying DNA extracted from soil to which nematodes were added. The soil standard curve was validated using sterilized soil inoculated with lower numbers of P. neglectus. A significant positive relationship (R2 = 0.66; P < 0.001) was observed for nematode numbers quantified from 15 field soils using qPCR and the Whitehead tray and microscopic method but the qPCR generally tended to provide higher estimates. Real-time PCR potentially provides a useful platform for efficient detection and quantification of P. neglectus directly from field soils.
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Farsi, M., VA Vanstone, JM Fisher, and AJ Rathjen. "Genetic variation in resistance to Pratylenchus neglectus in wheat and triticales." Australian Journal of Experimental Agriculture 35, no. 5 (1995): 597. http://dx.doi.org/10.1071/ea9950597.
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The root lesion nematode Pratylenchus neglectus occurs throughout the South Australian cereal belt, where it potentially contributes to yield loss. Genetic material was examined for resistance to P. neglectus, and included 2 susceptible local commercial wheat varieties (Spear, Molineux), 2 derivatives from Spear (RAC 613-27, RAC 613-47), wheat varieties varying in reaction to I? thornei, rye and rye derivatives, triticales, and 1R substitution lines in Chinese Spring. Seeds were surface-sterilised and germinated, and 3-day-old seedlings were inoculated with about 250 larvae and 150 eggs. Plants were grown in pots containing pasteurised soil and transferred to a controlled temperature waterbath at 22 � 1�C. After 7 weeks, nematodes were extracted and counted. A significant difference for the number of nematodes per plant and per gram dry root was found between the 3 main groups of genetic material: the wheat varieties, the substitution lines, and lines with the whole genome of rye (including triticales). The triticales Abacus and Muir showed the lowest number of nematodes (per gram root and per plant). None of the wheat varieties was resistant, so genetic mechanisms conferring resistance or tolerance to P. thornei are not effective against P. neglectus.
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Smiley, Richard W., Jennifer A. Gourlie, Guiping Yan, and Karl E. L. Rhinhart. "Resistance and Tolerance of Landrace Wheat in Fields Infested with Pratylenchus neglectus and P. thornei." Plant Disease 98, no. 6 (June 2014): 797–805. http://dx.doi.org/10.1094/pdis-10-13-1069-re.
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Pratylenchus neglectus and P. thornei reduce wheat yields in the Pacific Northwest of the United States. Resistant landrace cultivars have been identified using controlled environments. Field resistance and tolerance characteristics were compared over 3 years and two locations for four spring wheat cultivars: the susceptible ‘Alpowa’ and ‘Louise’ and the resistant landraces AUS28451 and Persia 20. Proportions and densities of P. neglectus and P. thornei differed across seasons and locations. Resistance was evaluated by comparing preplant and postharvest densities of nematodes in soil. Tolerance was evaluated by comparing grain yield and grain quality in plots treated or untreated by the nematicide aldicarb. Alpowa was susceptible and intolerant, Louise was susceptible and moderately tolerant, AUS28451 was resistant and intolerant, and Persia 20 was moderately susceptible and moderately intolerant. The species dominance shifted from P. neglectus to P. thornei in one field over a period of 3 years in apparent response to cultivars and crops planted. Estimates of economic loss caused by Pratylenchus spp. ranged from $8 to $20/ha. Economic benefits appear to be achievable by developing a spring wheat genotype with tolerance plus resistance, such as with a cross between AUS28451 and Louise.
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Kumari, S. "Pratylenchus neglectus (Nematoda: Pratylenchidae) under the rhizosphere of Brassica napus." Helminthologia 49, no. 2 (June 1, 2012): 92–95. http://dx.doi.org/10.2478/s11687-012-0019-9.
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AbstractSoil samples under the rhizosphere of Brasicca napus were collected from three localities (Bílé Podolí, Prague, Kylešovice). Two localities Prague and Kylešovice were positive for the presence of Pratylenchus neglectus. The species was identified using morphological features and the morphological identification was verified by using published species-specific primers and by sequencing 18S and 28S genes of ribosomal DNA.
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Wu, H. Y., Z. Z. Jia, J. Liu, J. Luo, and D. L. Peng. "First Report of Pratylenchus neglectus on Winter Wheat in China." Plant Disease 97, no. 1 (January 2013): 151. http://dx.doi.org/10.1094/pdis-04-12-0332-pdn.
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Root-lesion nematodes are major pathogens of wheat and have been reported in the United States, Mexico, India, Australia, Egypt, Canary Islands, South Africa, Iran, Japan, the Netherlands, Belgium, Italy, Germany, and Yugoslavia (1). They can also cause injury in a large number of crops, including grasses, cereal grains, and vegetables. In 2009 and 2010, a survey was conducted for nematodes in winter wheat fields near Taian city, Shandong, northern China. Root tissues were stained via the acid fuchsin tissue stain technique, and nematode numbers were recorded under a stereo microscope. Sixty-eight root samples were collected during the winter wheat growing season, and root lesion nematode was found in all samples. The highest average lesion nematode populations in fresh roots were 154.3 nematodes/g in 2009 and 236.7 nematodes/g in 2010. Nematodes were collected from infested wheat roots by a modified Baermann funnel method. Dimensions of the nematodes were: length, 0.42 to 0.54 mm; a, 18.8 to 24.2; b, 4.4 to 5.7; c, 19.8 to 25.4; V, 80.4 to 84.8; and spear, 17.1 to 18.9 μm. DNA was extracted from individual nematodes using liquid nitrogen. Amplification of rDNA-internal transcribed spacer region using the forward primers 5′-CGTAACAAGGTAGCTGTAG-3′ and the reverse primer 5′-TTTCACTCGCCGTTACTAAGG-3′ yielded a PCR fragment of approximately 900 bp. PCR products were purified using Universal Plant DNA Purification Kit (Tiangen, China) and ligated to the pMD18-T vector system (TaKaRa Bio, Japan) and transformed to E. coli strain DH5α. Plasmid DNA carrying the insert was extracted and used as the template for DNA sequencing. DNA sequencing was carried out in an ABI 3730, compared and aligned using MEGA 5.0. Sequences showed 96% sequence identity with those of Pratylenchus neglectus (GenBank Accession No. FR692291.1). The sequence was submitted to the GenBank database (JX228136). To our knowledge, this is the first report of P. neglectus infesting winter wheat in China. P. neglectus has been reported as causing economically significant damage to wheat production of up to 70% yield loss in the Pacific Northwest. Damage from lesion nematode may therefore be potentially significant to wheat production in Shandong Province, and further information should be obtained on its prevalence. References: (1) P. A. A. Loof. The family Pratylenchidae Thorne, 1949. W. R. Nickle, ed., Manual of Agricultural Nematol. Marcel Dekker, Inc. New York, 1991. (2) R. W. Smiley et al. J. Nematol. 37:45, 2005.
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Sharma, Shiveta, Shailendra Sharma, Tobias Keil, Eberhard Laubach, and Christian Jung. "Screening of barley germplasm for resistance to root lesion nematodes." Plant Genetic Resources 9, no. 2 (March 16, 2011): 236–39. http://dx.doi.org/10.1017/s1479262111000293.
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Root lesion nematodes of the genus Pratylenchus are important pests in crop cultivation that cause severe damage to crops throughout the world. P. neglectus is one of the most important members of this genus. The present study aimed to select barley accessions with resistance to P. neglectus in a greenhouse resistance test and to detect resistance quantitative trait loci (QTLs). Infection rates have been found to vary greatly among different barley accessions; however, immunity could not be found. An existing Igri × Franka doubled-haploid mapping population was used to map resistance genes after artificial inoculation with P. neglectus under controlled environment. QTLs were found with a likelihood of odds score between 2.71 and 6.35 and explaining phenotypic variation of 8 to 16%.
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Divsalar, Nafiseh, Ebrahim Shokoohi, Akbar Hoseinipour, and Phatu Mashela. "Molecular and morphological variation of the root-lesion nematode Pratylenchus neglectus." Biologia 74, no. 3 (November 28, 2018): 257–67. http://dx.doi.org/10.2478/s11756-018-00165-z.
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Smiley, Richard W., Jason G. Sheedy, and Sandra A. Easley. "Vertical Distribution of Pratylenchus spp. in Silt Loam Soil and Pacific Northwest Dryland Crops." Plant Disease 92, no. 12 (December 2008): 1662–68. http://dx.doi.org/10.1094/pdis-92-12-1662.
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Dryland field crops in the Pacific Northwest United States are commonly produced in silt loams infested by the root-lesion nematodes Pratylenchus neglectus and P. thornei. Soils at 30 sites in Oregon were sampled from 0 to 120 cm depth to examine the vertical distribution of these Pratylenchus spp. Both species were distributed through entire soil profiles of all cropping systems. Populations were generally greatest in the surface 30 cm, but sometimes high populations were detected at depths greater than 45 cm. Sampling to 30 cm depth allowed detection of more than 50% of the population in most sites, while sampling to 45 cm depth yielded more than 75% of the population in over 75% of the sites evaluated. Therefore, soil samples should be collected to 30 to 45 cm depth to accurately estimate populations of Pratylenchus spp. in dryland crops produced on silt loams in the Pacific Northwest. Populations of Pratylenchus spp. were found to be related to the most recently planted crop, with populations after barley, after wheat, and during summer fallow being detected in ascending order.
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Waeyenberge, Lieven, Alexander Ryss, Maurice Moens, Jorge Pinochet, and Thierry Vrain. "Molecular characterisation of 18 Pratylenchus species using rDNA Restriction Fragment Length Polymorphism." Nematology 2, no. 2 (2000): 135–42. http://dx.doi.org/10.1163/156854100509024.
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AbstractThe RFLP technique was used to establish a reliable diagnostic method for 18 Pratylenchus species: Pratylenchus agilis, P. bolivianus, P. brachyurus, P. coffeae, P. crenatus, P. fallax, P. goodeyi, P. loosi, P. mediterraneus, P. neglectus, P. penetrans, P. pratensis, P. pseudocoffeae, P. scribneri, P. subranjani, P. thornei, P. vulnus and P. zeae. The polymerase chain reaction (PCR) amplified the ITS regions from all species and populations examined and revealed large differences in length, ranging in size from approximately 900 to 1250 bp. The rDNA fragments were digested with five restriction enzymes (CfoI, DdeI, HindIII, HpaII, and PstI). All Pratylenchus species can be differentiated from each other by a combination of at least two enzymes. CfoI differentiated all nematode species with the exception of P. fallax, P. penetrans and P. pseudocoffeae. P. fallax was further separated by a DdeI restriction, and P. pseudocoffeae by a PstI digestion. Intraspecific RFLP were observed. Upon CfoI, DdeI, HindIII, or HpaII digestion, it was possible to separate the three P. coffeae populations studied from each other. La technique RFLP a été utilisée pour créer une méthode fiable de diagnostic pour 18 espèces de Pratylenchus: Pratylenchus agilis, P. bolivianus, P. brachyurus, P. coffeae, P. crenatus, P. fallax, P. goodeyi, P. loosi, P. mediterraneus, P. neglectus, P. penetrans, P. pratensis, P. pseudocoffeae, P. scribneri, P. subranjani, P. thornei, P. vulnus et P. zeae. La réaction de polymérisation en chaîne (PCR) a amplifié les régions de l’ITS pour toutes les espèces et populations étudiées et a mis en évidence de grandes différences dans la taille des gammes de longueur, de 900 à 1250 bp approximativement. Les fragments de rDNA ont été digérés à l’aide de cinq enzymes de restriction (CfoI, DdeI, HindIII, HpaII, and PstI). Toutes les espèces de Pratylenchus ont pu être différenciées les unes des autres par une combinaison d’au moins deux enzymes. CfoI a différencié toutes les espèces à l’exception de P. fallax, P. penetrans et P. pseudocoffeae. P. fallax a été ultérieurement séparé par une restriction DdeI, et P. pseudocoffeae par une digestion PstI. Des RFLP intraspécifiques ont été observés. Par les digestions CfoI, DdeI, HindIII, ou HpaII, il s’est révélé possible de séparer les unes des autres les trois populations étudiées de P. coffeae.
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Taylor, S. P., V. A. Vanstone, A. H. Ware, A. C. McKay, D. Szot, and M. H. Russ. "Measuring yield loss in cereals caused by root lesion nematodes (Pratylenchus neglectus and P. thornei) with and without nematicide." Australian Journal of Agricultural Research 50, no. 4 (1999): 617. http://dx.doi.org/10.1071/a98103.
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Yield loss caused by root lesion nematodes (Pratylenchus neglectus and P. thornei) was measured using the nematicide aldicarb (Temik 150GTM) or by correlating yield with initial or final nematode densities. In 1996, rotation trials (1 P. neglectus and 1 P. thornei) were established with susceptible and moderately resistant wheat varieties and resistant barley and triticale varieties. An intolerant oat variety (cv. Echidna) was planted over all plots in 1997. Nematode densities were 90% (P. neglectus) or 95% (P. thornei) lower in oat plots following the resistant triticale (cv. Tahara) relative to the susceptible wheat (cv. Machete). In 1997, a significant, negative correlation between both initial and final nematode density and yield was obtained. In wheat variety trials (3 sites) in 1997, a significant, negative correlation was also obtained between mean variety yield and mean final P. neglectus density or mean P. neglectus multiplication rate. Yield loss of up to 20% was calculated from the regression. In all trials, cereal varieties that were more resistant were also more tolerant. In 1996, aldicarb rate trials (1 P. neglectus and 1 P. thornei) were established to assess the affect of rate and timing of aldicarb application on yield of 2 susceptible/intolerant wheat varieties (cvv. Machete and Janz). Lower rates of aldicarb (≤1.5 kg a.i./ha) gave inconsistent nematode control and did not significantly increase yield. Rates ≥2.5 kg a.i./ha reduced nematode densities by 70–90%, resulting in up to 23% greater yield for Machete. The magnitude of yield loss caused by P. neglectus or P. thornei determined with or without nematicide was similar between trials.
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Yan, Guiping, Richard W. Smiley, Patricia A. Okubara, Andrea Skantar, Sandra A. Easley, Jason G. Sheedy, and Alison L. Thompson. "Detection and Discrimination of Pratylenchus neglectus and P. thornei in DNA Extracts from Soil." Plant Disease 92, no. 11 (November 2008): 1480–87. http://dx.doi.org/10.1094/pdis-92-11-1480.
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A species-specific polymerase chain reaction (PCR) method was developed to detect and identify the root-lesion nematodes Pratylenchus neglectus and P. thornei from soil. A primer set was designed from Pratylenchus 28S rRNA gene sequences of the D3 expansion domain. Primer specificity was confirmed with 23 isolates of 15 nematode species and other plant-parasitic and non-plant-parasitic nematodes typically present in the soil communities, and with six fungal species commonly associated with wheat root rot. DNA obtained using a commercially available kit and a method developed in our laboratory gave comparable amplification. PCR conditions were optimized and the two species were differentiated by PCR products of 144 bp for P. neglectus and 288 bp for P. thornei. With this assay, we detected a single juvenile in 1 g of sterile, inoculated soil. Examination of 30 field soil samples revealed that this method was applicable to a range of soils naturally infested with these two pathogens in Oregon. This PCR-based method is rapid, efficient, and reliable, does not require expertise in nematode taxonomy and morphology, and could be used as a rapid diagnostic tool for commercial and research applications for disease forecasting and management.
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Xia, Y. H., Y. K. Liu, P. H. Hao, H. X. Yuan, K. Wang, H. L. Li, and Y. Li. "Molecular and morphological characterization of the root -lesion nematode, Pratylenchus neglectus, on corn from Henan Province of China." Helminthologia 58, no. 4 (December 1, 2021): 385–93. http://dx.doi.org/10.2478/helm-2021-0044.
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Summary Root-lesion nematodes, Pratylenchus spp., are economically important pathogens because of their detrimental and economic impact on a wide range of crops. In August 2018, two samples of both roots and rhizosphere soil were collected from a corn field in Liangyuanqu of Shangqiu city, Henan Province, China. Root-lesion nematodes were recovered from the roots and soil samples using the modified Baermann funnel extraction method. Both the morphological characters and molecular analysis of the internal transcribed spacer (ITS) and D2-D3 expansion region of 28S ribosomal RNA sequences confirmed that the root-lesion nematode population collected from corn in this study was P. neglectus. Phylogenetic analyses showed that this isolate formed a highly supported clade with other P. neglectus isolates. To the best of our knowledge, this is the first report of P. neglectus on corn in Henan Province of China. This study reports the first partial sequences of 28S D2-D3 region of P. neglectus on corn in China. Due to the great harmfulness of root-lesion nematodes to corn, care should be taken to prevent the spread of P. neglectus to other regions in China. At the same time, further study on the biological characteristics of P. neglectus is needed, which will be helpful to develop corresponding management and control strategies.
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Yavuzaslanoglu, Elif, Halil I. Elekcioglu, Julie M. Nicol, Ozcan Yorgancilar, David Hodson, A. Faik Yildirim, Aysel Yorgancilar, and Necmettin Bolat. "Distribution, frequency and occurrence of cereal nematodes on the Central Anatolian Plateau in Turkey and their relationship with soil physicochemical properties." Nematology 14, no. 7 (2012): 839–54. http://dx.doi.org/10.1163/156854112x631926.
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The distribution of important plant-parasitic and free-living nematodes in the cereal production areas of the Central Anatolian Plateau (CAP) of Turkey was investigated with systematic surveys. Two important plant-parasitic nematode groups were found widely distributed; cereal-cyst nematodes (78.3%) and root-lesion nematodes (42.6%). Cereal cyst nematodes (CCN) were identified as Heterodera filipjevi in 18 provinces. Heterodera latipons was found in only one province. Pratylenchus thornei and P. neglectus were the most widely distributed species of root-lesion nematodes. Other frequently recorded plant-parasitic nematodes belonged to the genera Geocenamus (52.4%), Pratylenchoides (35.6%), Helicotylenchus (29.7%) and Paratylenchus (19.2%). Konya on the southern CAP had a significantly high incidence of P. neglectus as well as free-living nematodes. The incidence of CCN was greatest in areas of sandy soils on the CAP, with densities of up to 95 cysts (100 g soil)−1. Population densities of Geocenamus, Pratylenchus and Pratylenchoides were high in some locations. Soil physicochemical properties were investigated for their relationship to nematode distribution. There was a slight positive correlation of P. thornei and clay content; conversely, there was a significant negative correlation of P. neglectus with clay and a positive correlation with sand. Electrical conductivity (EC) was positively correlated with P. neglectus. Nematodes in the genera Helicotylenchus, Paratylenchus, Trophurus and Tylenchorhynchus were only recorded at low population densities in the sampled area. By contrast, nematodes in the genera Aphelenchus, Aphelenchoides, Ditylenchus, Dorylaimus, Tylenchus and bacterivorous genera had relatively high populations. Total free-living nematodes were positively correlated with EC and zinc (Zn) concentration. The Zn content of soil was generally at a level deficient for plant growth.
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Bahmani, Jebraeil, Farhad Khozeini, Shapour Barooti, Saeed Rezaee, and Reza Ghaderi. "PLANT-PARASITIC NEMATODES ASSOCIATED WITH WALNUT IN THE SANANDEJ REGION OF WEST IRAN." Journal of Plant Protection Research 53, no. 4 (October 1, 2013): 404–8. http://dx.doi.org/10.2478/jppr-2013-0060.
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Abstract A survey of plant-parasitic nematodes associated with walnut was carried out in the Sanandej region, of the province of Kurdistan, in western Iran, during the 2011-2012 time period. After taking samples from fifty-four localities and then doing the routine laboratory work for processing, fixing, and mounting of the nematodes, twenty-one species of plant-parasitic nematodes were finally identified. Among the identified species: Cacopaurus pestis, Mesocriconema xenoplax, Pratylenchus vulnus and Meloidogyne incognita are likely to cause damage. Spiral (Helicotylenchus crassatus, H. digonicus, H. pseudorobustus and H. vulgaris), ring (Mesocriconema antipolitanum and M. xenoplax) and root-lesion nematodes (Pratylenchus neglectus, P. thornei, P. vulnus and P. delattrei) were the most predominant nematodes in the sampled area (frequencies in soil were 87.0, 77.8, and 72.2% and 46.3, 20.4 and 14.8% in root samples, respectively). In the present study, Pratylenchus delattrei, Trophurus lomus, Paratylenchus similis, Geocenamus stegus, Helicotylenchus crassatus, Scutellonema brachyurus and Meloidogyne incognita were reported as new species associated with walnut in Iran.
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Riley, I. T., and S. J. Kelly. "Endoparasitic nematodes in cropping soils of Western Australia." Australian Journal of Experimental Agriculture 42, no. 1 (2002): 49. http://dx.doi.org/10.1071/ea01054.
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Soil samples were collected in Western Australia from cereal fields at about harvest time to determine levels of the endoparasitic nematodes, Pratylenchus and Heterodera. A systematic survey in 1997 and 1998 centred on the 40 shires with the highest proportion of cereal cropping. One hundred and eighty samples were collected in 1997 and 227 in 1998 at 10-km intervals along north–south transects 35 km apart. A targeted survey in 1997 included 98 soil samples from fields selected by growers as having poor productivity without an evident cause. No Heterodera cysts were found in any survey sample but these could be extracted from soils previously known to be infested. Pratylenchus neglectus was most commonly detected followed by P. thornei and P. zeae. Populations identified as P. brachyurus, P. penetrans, P. scribneri, and an undescribed species similar to P. thornei were also found. Overall Pratylenchus was extracted from 63% of samples (mean 1.1, median 0.3, max. 22.0/mL of soil). Maps of the data indicate that Pratylenchus populations were aggregated with some areas having relatively light infestations. There was a positive relationship with the intensity of cereal cropping and a negative relationship with pulse cropping. The findings indicate that potentially damaging Pratylenchus numbers occur in a significant proportion of fields and highlight the need to develop and implement strategies to lower population densities.
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DUMAN, Nagihan, Göksel ÖZER, Abdelfattah DABABAT, and Mustafa İMREN. "Host suitability of wheat cultivars to Pratylenchus thornei Sher & Allen, 1953 and Pratylenchus neglectus (Rensch, 1924) (Tylenchida: Pratylenchidae)." Turkish Journal of Entomology 45, no. 2 (June 1, 2021): 235–43. http://dx.doi.org/10.16970/entoted.892883.
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Morales Salmerón, Laura, Diana Martín-Lammerding, José Luis Tenorio Pasamón, and Sara Sánchez-Moreno. "Effects of cover crops on soil biota, soil fertility and weeds, and Pratylenchus suppression in experimental conditions." Nematology 21, no. 3 (2019): 227–41. http://dx.doi.org/10.1163/15685411-00003208.
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Summary Cover crops are used in Mediterranean agrosystems to reduce soil degradation and restore soil function. We carried out an experiment to test the effects of two cover crops (Brachypodium distachyon and Trifolium subterraneum, mulched or incorporated) and two bare soil controls (fertilised and unfertilised) on soil properties, biodiversity, and soil natural suppressiveness against Pratylenchus neglectus in pot microcosms. Cover crop performance, weed infestation, litter decomposition rates, soil properties, and the response of soil biota (nematode indicators, mesofauna feeding activity, enzymatic activity, and mycorrhizal spores) were measured. A short-term suppressiveness experiment was performed to determine P. neglectus colonisation of wheat roots after each treatment. Trifolium subterraneum incorporation significantly enhanced the fungal-mediated decomposition channel and decomposition rates, but enzymatic activities and mycorrhizal spore abundances did not respond to the experimental treatments. Cover crops were effective at controlling weeds, but did not increase soil suppressiveness against P. neglectus. Brachypodium distachyon cover cropping increased root infection.
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Sharma, Shiveta, Shailendra Sharma, Friedrich J. Kopisch-Obuch, Tobias Keil, Eberhard Laubach, Nils Stein, Andreas Graner, and Christian Jung. "QTL analysis of root-lesion nematode resistance in barley: 1. Pratylenchus neglectus." Theoretical and Applied Genetics 122, no. 7 (February 6, 2011): 1321–30. http://dx.doi.org/10.1007/s00122-011-1533-8.
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Yavuzaslanoglu, Elif, Ozlem Ates Sonmezoglu, Nimet Genc, Z. Mutlu Akar, Atilla Ocal, M. Sait Karaca, I. Halil Elekcioglu, V. Soner Ozsoy, and Metin Aydogdu. "Occurrence and abundance of nematodes on onion in Turkey and their relationship with soil physicochemical properties." Nematology 21, no. 10 (2019): 1063–79. http://dx.doi.org/10.1163/15685411-00003275.
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Summary The distribution of plant-feeding and free-living nematodes in large scale onion production areas in five geographical regions in Turkey was investigated in 2016 and 2017. Ditylenchus spp. and Tylenchus spp. were widely distributed. The stem and bulb nematode, Ditylenchus dipsaci, was found in 48 locations from 13 provinces. Other plant-feeding nematode genera were Pratylenchus, Paratylenchus and Pratylenchoides. Pratylenchus thornei was the most widely distributed root-lesion nematode species in onion fields in 11 locations from seven provinces. Pratylenchus neglectus was present in three locations and P. vulnus was in four locations. Aphelenchus spp. and Aphelenchoides spp. were the principal fungal-feeding nematodes in onion-growing areas. The most abundant bacterial-feeding nematode genera were Acrobeloides, Cephalobus, Eucephalobus and Rhabditis. Acrobeles and Wilsonema genera were low in occurrence and abundance. Nematodes from Dorylaimida and predator nematodes, Mononchus spp., were also found. The numbers of Ditylenchus from plant samples were significantly correlated positively to silt content, and significantly correlated negatively to organic matter and calcium content.
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Vanstone, V. A., A. J. Rathjen, A. H. Ware, and R. D. Wheeler. "Relationship between root lesion nematodes (Pratylenchus neglectus and P. thornei) and performance of wheat varieties." Australian Journal of Experimental Agriculture 38, no. 2 (1998): 181. http://dx.doi.org/10.1071/ea97109.
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Summary. The root lesion nematodes Pratylenchus neglectus andP. thornei occur throughout the cereal cropping areas of South Australia. In 1996, field trials on the Eyre Peninsula of South Australia were assessed to determine the relationship between density of nematodes within field plots in early October and harvested grain yield of 9 wheat varieties. The Pratylenchus species present was either P. neglectus (at Streaky Bay, Minnipa and Kalanbi) or P. thornei (at Nunjikompita). Absence of other major yield limiting factors at these sites in 1996 enabled determination of the relationship between nematode population and wheat yield. There was a significant, negative correlation between mean yield and nematode populations for the 9 varieties at 3 of the sites (P<0.01 for Streaky Bay and Nunjikompita; P<0.05 for Minnipa). Root lesion nematodes were responsible for 56–74% of the observed varietal differences in yield at these sites. The tolerant variety Excalibur yielded 19% (Streaky Bay), 23% (Minnipa) or 33% (Nunjikompita) more than the intolerant variety Spear, and Excalibur resulted in 69, 63 or 66% fewer nematodes, respectively, than in plots of Spear. Although nematode populations could not be assessed at the Kalanbi site, varietal yield relations were similar to the other sites, with Excalibur yielding 18% more than Spear. The 9 varieties were ranked for both resistance and tolerance to the 2 nematode species.
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Kelly, Sean, and Ian Riley. "Radopholus nativus (Nematoda: Pratylenchidae), a potential economic pest of wheat in Western Australia." Nematology 3, no. 1 (2001): 25–30. http://dx.doi.org/10.1163/156854101300106856.
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AbstractLarge population densities (more than 100 000 per g dry weight of roots) of Radopholus nativus apparently caused economic damage to wheat near Wyalkatchem, Western Australia. Plants in large areas of poor growth were colonised by R. nativus, whereas in areas of better growth Pratylenchus neglectus occurred at lower population densities. The boundary between the areas was distinct. In the same year (1998), a further nine wheat samples were found to be infested with R. nativus through examination of 300 diagnostic samples submitted by Western Australian growers. Mixed Radopholus/Pratylenchus populations occurred in six of those samples. Populations of R. nativus were widely dispersed throughout the cropping areas of the State. It is concluded that R. nativus has the potential under certain conditions and/or crop rotations to reach high population density and cause economic loss.
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Smiley, Richard W., Stephen Machado, Jennifer A. Gourlie, Larry C. Pritchett, Guiping Yan, and Erling E. Jacobsen. "Effects of Crop Rotations and Tillage on Pratylenchus spp. in the Semiarid Pacific Northwest United States." Plant Disease 97, no. 4 (April 2013): 537–46. http://dx.doi.org/10.1094/pdis-08-12-0788-re.
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There is interest in converting rainfed cropping systems in the Pacific Northwest from a 2-year rotation of winter wheat and cultivated fallow to direct-seed (no-till) systems that include chemical fallow, spring cereals, and food legume and brassica crops. Little information is available regarding effects of these changes on plant-parasitic nematodes. Eight cropping systems in a low-precipitation region (<330 mm) were compared over 9 years. Each phase of each rotation occurred each year. The density of Pratylenchus spp. was greater in cultivated than chemical fallow, became greater with increasing frequency of host crops, and was inversely associated with precipitation (R2 = 0.92, α < 0.01). Densities after harvesting mustard, spring wheat, winter wheat, and winter pea were greater (α < 0.01) than after harvesting spring barley or spring pea. Camelina also produced low densities. Winter wheat led to a greater density of Pratylenchus neglectus and spring wheat led to a greater density of P. thornei. Density of Pratylenchus spp. was correlated (R2 = 0.88, α < 0.01) but generally higher when detected by real-time polymerase chain reaction on DNA extracts from soil than when detected by a traditional method. Selection of different Pratylenchus spp. by different wheat cultivars or growth habit must be addressed to minimize the level of nematode risk to future plantings of intolerant crops.
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Ballard, R. A., R. E. Hutton, S. P. Taylor, A. C. McKay, and J. H. Howie. "Field resistance of annual pasture legumes to the root lesion nematode,Pratylenchus neglectus." Australasian Plant Pathology 35, no. 3 (2006): 303. http://dx.doi.org/10.1071/ap06019.
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Williams, K., S. Taylor, P. Bogacki, M. Pallotta, H. Bariana, and H. Wallwork. "Mapping of the root lesion nematode (Pratylenchus neglectus) resistance gene Rlnn1 in wheat." Theoretical and Applied Genetics 104, no. 5 (April 2002): 874–79. http://dx.doi.org/10.1007/s00122-001-0839-3.
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Zwart, R. S., J. P. Thompson, and I. D. Godwin. "Identification of quantitative trait loci for resistance to two species of root-lesion nematode (Pratylenchus thornei and P. neglectus) in wheat." Australian Journal of Agricultural Research 56, no. 4 (2005): 345. http://dx.doi.org/10.1071/ar04223.
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Pratylenchus thornei and P. neglectus are two species of root-lesion nematode that cause substantial yield losses in wheat. No commercially available wheat variety has resistance to both species. A doubled-haploid population developed from a cross between the synthetic hexaploid wheat line CPI133872 and the bread wheat Janz was used to locate and tag quantitative trait loci (QTLs) associated with resistance to both P. thornei and P. neglectus. Wheat plants were inoculated with both species of nematode in independent replicated glasshouse trials repeated over 2 years. Known locations of wheat microsatellite markers were used to construct a framework map. After an initial single-marker analysis to detect marker-trait linkages, chromosome regions associated with putative QTLs were targetted with microsatellite markers to increase map density in the chromosome regions of interest. In total, 148 wheat microsatellite markers and 21 amplified fragment length polymorphism markers were mapped. The codominant microsatellite marker Xbarc183 on the distal end of chromosome 6DS was allelic for resistance to both P. thornei and P. neglectus. The QTL were designated QRlnt.lrc-6D.1 and QRlnn.lrc-6D.1, for the 2 traits, respectively. The allele inherited from CPI133872 explained 22.0–24.2% of the phenotypic variation for P. thornei resistance, and the allele inherited from Janz accounted for 11.3–14.0% of the phenotypic variation for P. neglectus resistance. Composite interval mapping identified markers that flank a second major QTL on chromosome 6DL (QRlnt.lrc-6D.2) that explained 8.3–13.4% of the phenotypic variation for P. thornei resistance. An additional major QTL associated with P. neglectus resistance was detected on chromosome 4DS (QRlnn.lrc-4D.1) and explained a further 10.3–15.4% of the phenotypic variation. The identification and tagging of nematode resistance genes with molecular markers will allow appropriate allele combinations to be selected, which will aid the successful breeding of wheat with dual nematode resistance.
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Soriano, I. R., R. E. Asenstorfer, O. Schmidt, and I. T. Riley. "Inducible Flavone in Oats (Avena sativa) Is a Novel Defense Against Plant-Parasitic Nematodes." Phytopathology® 94, no. 11 (November 2004): 1207–14. http://dx.doi.org/10.1094/phyto.2004.94.11.1207.
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The induction of defense compounds in oats (Avena sativa) in response to invasion by parasitic nematodes and to application of the wound hormone methyl jasmonate was examined. Oats cv. Quoll seedlings were challenged with Pratylenchus neglectus, Heterodera avenae, and Ditylenchus dipsaci and treated with 1 × 10-4 M methyl jasmonate. Three compounds, isolated in methanolic root and shoot extracts of oats, exhibiting an absorbance spectrum typical of flavone glycosides, were induced by nematode invasion and methyl jasmonate. These were identified as flavone-C-glycosides by mass spectrometry. The effect of the flavone-C-glycosides on the invasion by and development of cereal cyst nematode H. avenae was assessed using methanolic extracts of shoots and roots from methyl jasmonate-treated plants. Both extracts impaired nematode invasion and development. When the extracts were fractionated by high voltage paper electrophoresis, only one flavone-C-glycoside, O-methyl-apigenin-C-deoxyhexoside-O-hexoside, inhibited nematode invasion. The protective effect of the induction of flavone-C-glycosides in oats by methyl jasmonate was evaluated against H. avenae and P. neglectus. Treatment with methyl jasmonate reduced invasion of both nematodes and increased plant mass, compensating for damage caused by the nematodes, and is attributed to the active flavone-C-glycoside. The active compound, O-methyl-apigenin-C-deoxyhexoside-O-hexoside, has not been implicated previously in plant defense against any pest or pathogen, and appears to provide protection against the major cereal nematodes Heterodera and Pratylenchus.
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Fatemy, S., E. Abootorabi, N. Ebrahimi, and F. Aghabeigi. "First Report of Pratylenchus neglectus and P. thornei Infecting Canola and Weeds in Iran." Plant Disease 90, no. 12 (December 2006): 1555. http://dx.doi.org/10.1094/pd-90-1555b.
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Cultivation of canola (Brassica napus L.) is relatively new in Iran. Because nearly 90% of Iran's edible oil is imported, farmers are subsidized and encouraged to grow this crop. Except for the sugar beet cyst nematode, Heterodera schachtii, to which susceptibility of some canola cultivars has been established (1), information on other nematode pests of canola is lacking. During a survey from April—May 2002 and repeated in 2003, soil and root samples of winter canola and weeds were collected at harvest of canola from research stations and farmers' fields in the south, west, and northwest of Tehran Province. Each sample was a composite of 25 roots and 2 kg of soil per hectare, collected from the rhizosphere of canola with a 2.5-cm-diameter soil corer. Samples were put in plastic bags and kept at 5°C until they were processed, within 2 weeks from sampling. Samples were sieved through a 0.840-cm aperture sieveand mixed thoroughly. Nematodes were extracted from subsamples of 5 g of roots and 250 g of soil with a modification of the sugar centrifugal flotation method (2), counted, and identified. Two species of root lesion nematodes, Pratylenchus neglectus and P. thornei, were found. When they were present in the same field, they occurred in the roots of both Regents × Cobra and Orient cultivars. Averages of 28 and 321 P. thornei per gram were found in the roots of cvs. Regents × Cobra and Orient, respectively. Averages of 30, 1,026, 626, and 450 P. neglectus per gram of roots of cvs. Regents × Cobra, Orient, Ocapi, and GLSIO were detected, respectively, in different fields. Heavily infected plants were stunted and had roots with dark lesions, a symptom typical of the attacks by these nematodes. Generally, greater nematode densities were in the roots than in the soil and both nematode species were more abundant in cooler than in warmer areas of the province. Since these nematodes are also severe pests of wheat, which is also grown in the province, they could pose a potential threat to both crops. Weeds that were present in the sampled fields belonged to the botanical families Scrophulariaceae, Gramineae, Euphorbiaceae, Crucifereae, and Compositeae. Between 22 and 1,500 P. thornei and 17 P. neglectus per gram of roots of Crucifereae and 280 P. thornei per gram of roots of Gramineae were found. To our knowledge, this is the first report of lesion nematodes infecting canola plants in Iran. References: (1) S. Fatemy and E. Abootorabi. Nematol. Mediterr. 30:163, 2002. (2) W. R. Jenkins. Plant Dis. Rep. 48:692, 1964.
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Kim, Dongwoo, Hwal-Su Hwang, Jae-Kyoung Shim, JiYoung Yang, Jae Hong Pak, and Kyeong-Yeoll Lee. "Molecular biodiversity assessment of plant-parasitic nematodes in Dokdo Island, Korea." Nematology 21, no. 3 (2019): 275–92. http://dx.doi.org/10.1163/15685411-00003213.
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Summary Dokdo Island has a unique biodiversity that has been preserved as a natural monument. Although the biodiversity of Dokdo has been investigated, little information is available regarding the nematodes. The diversity of plant-parasitic nematodes was investigated using both ITS and D2-D3 sequences. Nematodes extracted from 59 rhizosphere soil samples were morphologically identified as belonging to eight genera: Geocenamus, Helicotylenchus, Rotylenchulus, Heterodera, Paratylenchus, Pratylenchus, Pratylenchoides and Xiphinema. Further, nucleotide sequences were determined from 85 individuals of different genera for species diagnosis. We identified 13 species, including three species of the genus Pratylenchus (P. crenatus, P. kumamotoensis and P. neglectus), Helicotylenchus sp. 1, Rotylenchulus sp. 1, Paratylenchus nanus, Heterodera trifolii, Heterodera spp., Pratylenchoides ritteri, Geocenamus sp. 1, Geocenamus sp. 2, Xiphinema brevicollum and Xiphinema sp. 1. The dominant plant-parasitic nematode on Dokdo was P. crenatus, which was found in 25.4% of the samples. Our study provides important information about the biodiversity of plant-parasitic nematodes on Dokdo Island.
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Navas-Cortés, Juan, Blanca Landa, Nicola Vovlas, Gracia Liébanas, Pablo Castillo, Juan Palomares-Rius, and Sergei Subbotin. "Description of Pratylenchus hispaniensis n. sp. from Spain and considerations on the phylogenetic relationship among selected genera in the family Pratylenchidae." Nematology 12, no. 3 (2010): 429–51. http://dx.doi.org/10.1163/138855409x12559479585043.
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AbstractA new amphimictic species, Pratylenchus hispaniensis n. sp., parasitising the roots of gum cistus in Andújar (Jaén), southern Spain, is described. The new species is characterised by the presence of numerous males and by the female having a lip region with three annuli, a divided face, a robust stylet (14.5-17.0 μm) with rounded knobs, lateral fields with four lines, V = 80-84, a round spermatheca full of sperm, well developed post-vulval uterine sac and an obliquely truncate tail with irregularly annulated terminus. Morphologically this species is related to P. bhatti, P. kralli, P. mediterraneus, P. pseudofallax and P. thornei. A phenetic study of the 25 most useful diagnostic morphological and allometric characters for Pratylenchus species was done using multivariate factor and linear discriminant analyses. In the factor analysis the first seven factors accounted for 71.1% of the total variance of the characters selected. These factors were related to female tail, pharyngeal overlap, reproductive behaviour, stylet length, L/post-vulval uterine sac ratio, body length and number of lip annuli. Discriminant analysis differentiated Pratylenchus spp. from the three valid species of Zygotylenchus. The results of the phylogenetic analysis based on sequences of the D2-D3 expansion regions of 28S, partial 18S and ITS rRNA genes confirmed the close relationship of P. hispaniensis n. sp. with P. mediterraneus and inferred molecular affinity with P. brzeskii, P. neglectus and P. thornei, in spite of variation in the position of P. hispaniensis n. sp. in the clades. Additional phylogenetic analyses based on the same sets of sequences for P. hispaniensis n. sp., Zygotylenchus guevarai and other Pratylenchidae indicated that Pratylenchus includes several paraphyletic lineages; however, likelihood tests did not reject monophyly of the genus. The inclusion of Pratylenchus, Zygotylenchus, Hirschmanniella, Nacobbus and Apratylenchus in Pratylenchidae was supported.
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Huang, Danqiong, and Guiping Yan. "Specific Detection of the Root-Lesion Nematode Pratylenchus scribneri Using Conventional and Real-Time PCR." Plant Disease 101, no. 2 (February 2017): 359–65. http://dx.doi.org/10.1094/pdis-07-16-1013-re.
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Pratylenchus scribneri is a plant-parasitic root-lesion nematode causing economic damage to various crops worldwide. Identifying root-lesion nematodes to species using traditional morphological methods is an arduous task requiring extensive training on nematode taxonomy and years of experience. Thus, molecular methods for P. scribneri detection and identification were developed. Conventional and real-time polymerase chain reaction (PCR) assays with new species-specific primers were used in this study, which exclusively amplified DNA of P. scribneri but not DNA from other Pratylenchus spp. or non-Pratylenchus spp. tested. Compared with conventional PCR that was able to detect an equivalent to 1/4 of the DNA of a single nematode, real-time PCR was more sensitive and could amplify an equivalent to 1/128 of the DNA of one nematode. Both conventional and real-time PCR assays successfully identified P. scribneri and distinguished it from P. penetrans and P. neglectus isolated from field samples collected from various locations in North Dakota and Minnesota. The Blast-search based on the sequence information confirmed the reliability of the PCR assays for species identification. This is the first report of P. scribneri identification using a real-time PCR assay. The developed PCR assays are suitable for use in diagnostic laboratories and detection of field infestations with this nematode species.
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Li, Y., S. Wang, J. Du, Q. S. Lu, Z. Y. Wang, K. Wang, and H. L. Li. "First Report of the Root-Lesion Nematode (Pratylenchus neglectus) on Wheat in Anhui Province, China." Plant Disease 102, no. 12 (December 2018): 2663. http://dx.doi.org/10.1094/pdis-05-18-0764-pdn.
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MISTANOĞLU, İbrahim, Gülsüm UYSAL, and Zübeyir DEVRAN. "Anason yetiştirilen alanlarda önemli bitki paraziti nematodlarının dağılımı ve tanımlanması." Turkish Journal of Entomology 46, no. 3 (September 30, 2022): 323–33. http://dx.doi.org/10.16970/entoted.1098172.
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Anise, Pimpinella anisum L. (Apiales: Apiaceae) is an important medicinal aromatic plant and can be attacked by different pests and pathogens. Plant parasitic nematodes are important pests that can be confused with nutrient deficiency or symptoms of various diseases or pests. Therefore, rapid and accurate identification of these pests is essential for integrated nematode management and rotation. In 2021, a survey was conducted in Bolvadin District of Afyonkarahisar Province, which is one of the most important anise production areas of Türkiye. Forty-two soil samples were collected from the anise growing areas in the district and 16 species-specific primers were used for molecular identification of plant parasitic nematodes. In the samples, Meloidogyne hapla Chitwood, 1949 (Tylenchida: Heteroderidae), Pratylenchus neglectus (Rensch, 1924) Filipjev & Schuurmans Stekhoven, 1941, Pratylenchus thornei Sher & Allen, 1953 (Tylenchida: Pratylenchidae) and Aphelenchoides besseyi Christie, 1942 (Aphelenchida: Aphelenchoididae), were detected at the rates of 57% (24), 52% (22), 36% (15) and 7% (3), respectively. Plant parasitic nematodes were found in both single and mixed populations. In addition, A. besseyi was found for the first time in anise growing areas.
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Jayatilake, Dimanthi V., Elise J. Tucker, Harbans Bariana, Haydn Kuchel, James Edwards, Alan C. McKay, Ken Chalmers, and Diane E. Mather. "Genetic mapping and marker development for resistance of wheat against the root lesion nematode Pratylenchus neglectus." BMC Plant Biology 13, no. 1 (2013): 230. http://dx.doi.org/10.1186/1471-2229-13-230.
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Oldach, Klaus H., David M. Peck, Ramakrishnan M. Nair, Maria Sokolova, John Harris, Paul Bogacki, and Ross Ballard. "Genetic analysis of tolerance to the root lesion nematode Pratylenchus neglectus in the legume Medicago littoralis." BMC Plant Biology 14, no. 1 (2014): 100. http://dx.doi.org/10.1186/1471-2229-14-100.
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Yan, G. P., A. Plaisance, D. Huang, Z. Liu, V. Chapara, and Z. A. Handoo. "First Report of the Root-lesion Nematode Pratylenchus neglectus on Wheat (Triticum aestivum) in North Dakota." Plant Disease 100, no. 8 (August 2016): 1794. http://dx.doi.org/10.1094/pdis-02-16-0260-pdn.
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