Nematology最新文献

{"title":"Reaction of Brazilian genotypes of pulses (pea, chickpea and lentil) to the root-knot nematode Meloidogyne enterolobii","authors":"Thávio Júnior B Pinto, Dwillian F Cunha, G. Silva, J. Pinheiro, Valdir R. Correia, C. F. Ragassi, J. Cares","doi":"10.1163/15685411-bja10309","DOIUrl":"https://doi.org/10.1163/15685411-bja10309","url":null,"abstract":"\u0000The root-knot nematode, Meloidogyne enterolobii, is an important pathogen of numerous crops, including the so-called pulses. Hence, it is necessary to identify genetic resistance, as it is the most efficient, cost-effective, and environmentally sound way to manage nematodes in the field. The objective of this study was to screen a Brazilian germplasm collection of pulse crops (peas, chickpeas, and lentils) comprising accessions from the Embrapa Germplasm Bank and commercial cultivars against M. enterolobii under glasshouse conditions. The experiment was conducted with 23 treatments (genotypes), i.e., 14 pea, six chickpea and one lentil genotype, and two tomato cultivars, ‘Rutgers’ (susceptible) and ‘Nemadoro’ (resistant). Each plant (replication) was inoculated with 5000 eggs and second-stage juveniles (J2) of M. enterolobii and evaluated 65 days after inoculation, considering the following variables: gall index, egg mass index, number of eggs per g of roots, and reproduction factor. The experiments were conducted at two independent time points (summer and autumn/winter). Results showed that all 23 plant genotypes were susceptible to the nematode, with pea genotype ‘Itapuã’ being intolerant to infection. Cultivation of pulse crops has been steadily increasing both in Brazil and worldwide. Our research findings make a valuable contribution to the ongoing efforts to identify genetic resistance to nematode pathogens that can significantly affect the productivity of these crops. By identifying and developing resistant genotypes, pulse crop yields can be safeguarded, and sustainable agricultural practices can be supported.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140457018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nematode production in artificial ponds: a long-term perspective","authors":"N. Majdi, Birgit Gansfort, S. Gehner, W. Traunspurger","doi":"10.1163/15685411-bja10311","DOIUrl":"https://doi.org/10.1163/15685411-bja10311","url":null,"abstract":"\u0000Nematodes are the most abundant multicellular animals on Earth and play an important role as intermediaries in energy fluxes. However, estimations of nematode biomass turnover and secondary production have been poorly defined for decades and it is difficult to reach a consensus about the importance of nematodes for ecosystem functioning. Here we monitored monthly the nematode species composition, abundance and biomass over 3-10 years in a set of artificial urban ponds, and we used different allometric models to estimate biomass turnover and secondary production. During the first 3 years of colonisation of the pond bottom, the nematode community was rather species-poor and mostly composed of small bacterivorous species (Monhysterids); however, the community quickly reached impressive numbers (up to 21 million individuals m−2) achieving a maximum annual production of 3.8-11.6 gC m−2 year−1 depending on the allometric model used for estimation. However, over the long-term (3-10 years), abundance and community structure eventually became dramatically altered by anoxic events occurring in one pond, dampening nematode production to low levels (0.3-0.6 gC m−2 year−1) without clear resilience. The comparison of models helped us to formulate general recommendations in order to popularise the use of nematode secondary production as a useful ecosystem diagnostic tool. Overall, results indicated that under good conditions of oxygenation nematodes are a highly productive component of the zoobenthos of ponds. We also discussed the consequences of this finding for sustainable pond aquaculture, as nematodes constitute an important local and nutritive resource for juveniles of economically important fish, such as carp and tilapia.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139842916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nematode production in artificial ponds: a long-term perspective","authors":"N. Majdi, Birgit Gansfort, S. Gehner, W. Traunspurger","doi":"10.1163/15685411-bja10311","DOIUrl":"https://doi.org/10.1163/15685411-bja10311","url":null,"abstract":"\u0000Nematodes are the most abundant multicellular animals on Earth and play an important role as intermediaries in energy fluxes. However, estimations of nematode biomass turnover and secondary production have been poorly defined for decades and it is difficult to reach a consensus about the importance of nematodes for ecosystem functioning. Here we monitored monthly the nematode species composition, abundance and biomass over 3-10 years in a set of artificial urban ponds, and we used different allometric models to estimate biomass turnover and secondary production. During the first 3 years of colonisation of the pond bottom, the nematode community was rather species-poor and mostly composed of small bacterivorous species (Monhysterids); however, the community quickly reached impressive numbers (up to 21 million individuals m−2) achieving a maximum annual production of 3.8-11.6 gC m−2 year−1 depending on the allometric model used for estimation. However, over the long-term (3-10 years), abundance and community structure eventually became dramatically altered by anoxic events occurring in one pond, dampening nematode production to low levels (0.3-0.6 gC m−2 year−1) without clear resilience. The comparison of models helped us to formulate general recommendations in order to popularise the use of nematode secondary production as a useful ecosystem diagnostic tool. Overall, results indicated that under good conditions of oxygenation nematodes are a highly productive component of the zoobenthos of ponds. We also discussed the consequences of this finding for sustainable pond aquaculture, as nematodes constitute an important local and nutritive resource for juveniles of economically important fish, such as carp and tilapia.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139783037","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of allelic Mi-1.2 dosage effects on levels of resistance to virulent and avirulent Meloidogyne spp. populations in some tomato rootstocks","authors":"Márcia Gabriel, Marcilene F. A. Santos, V. S. Mattos, Sheila F. Almeida, L. Boiteux, R. G. Carneiro","doi":"10.1163/15685411-bja10308","DOIUrl":"https://doi.org/10.1163/15685411-bja10308","url":null,"abstract":"\u0000The -1.2 gene confers broad-spectrum resistance to populations of at least 13 Meloidogyne species, being present in a wide range of commercial tomato (Solanum lycopersicum) cultivars. A more refined assessment of the allelic dosage effects of the -1.2 gene to virulent and avirulent Meloidogyne populations may provide relevant information for the management of the durability of the resistance under field conditions. Herein, the allelic dosage effects (homozygous vs heterozygous at the -1.2 locus) on the phenotypic expression of resistance were evaluated against one -1.2-virulent and six avirulent Meloidogyne spp. populations. Seven tomato rootstocks with distinct allelic conditions at the -1.2 locus and one susceptible control (‘Santa Clara’) were used in the present study. Significant dosage effects of -1.2 alleles in reducing the reproduction factors (RF) were observed, but restricted to the avirulent Meloidogyne populations. Homozygous resistant (-1.2/-1.2) cultivars, except TD1, prevented reproduction of almost avirulent Meloidogyne spp. populations in contrast with the heterozygous allele combination (-1.2/-1.2), which allowed a certain level of nematode reproduction. The efficiency and durability of the -1.2 gene depend on its proper management under commercial field conditions. Heterozygous (-1.2/-1.2) plants will increase the population of Meloidogyne spp., with no drastic reduction as occurring in the case of homozygous resistant, and they allow a small reproduction of more adapted sub-populations of the nematode, which might increase over time. Therefore, our results strongly indicated that the employment (whenever possible) of hybrids carrying the double dosage of the -1.2 gene would reduce the potential of high nematode populations in plants with this allelic configuration.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139790892","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mating sub-behaviours in Bursaphelenchus xylophilus on agar and evidence for female cooperation","authors":"Kentaro Doi, R. Shinya","doi":"10.1163/15685411-bja10310","DOIUrl":"https://doi.org/10.1163/15685411-bja10310","url":null,"abstract":"\u0000The pine wood nematode, Bursaphelenchus xylophilus, is the cause of pine wilt disease and reproduces by copulation within host pine trees. Female mate selection in B. xylophilus mating behaviour has been reported but definitive evidence is lacking. Furthermore, while the mating behaviour of the free-living nematode Caenorhabditis elegans on agar has been well understood, the mating behaviour of B. xylophilus on agar has not been studied in detail, and the differences in their characteristics remain unclear. Here, we addressed these knowledge gaps by observing B. xylophilus mating behaviour on agar. We identified six primary mating sub-behaviours in B. xylophilus males. Comparative analysis with C. elegans revealed distinct differences in the sequence of mating stages. Notably, B. xylophilus males actively searched for the female’s vulva during the wrapping stage, whereas females exhibited back-and-forth locomotion to align the male spicule with the vulva location. Additionally, we conducted mating assays using anaesthetised female nematodes to evaluate the female’s role in the mating behaviours of B. xylophilus. The mating duration increased significantly when females were anaesthetised, and the probabilities of reaching the wrapping and vulva location stages were reduced. Therefore, B. xylophilus females actively cooperate in mating behaviours. Our findings highlight unique aspects of mating behaviours in B. xylophilus and provide insights concerning differences in mating behaviours between B. xylophilus and C. elegans.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139851690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A taxonomic update on Tylenchorhynchus annulatus (Nematoda: Dolichodoridae), a widely distributed stunt nematode species","authors":"Phougeishangbam Rolish Singh, A. Hajihassani","doi":"10.1163/15685411-bja10312","DOIUrl":"https://doi.org/10.1163/15685411-bja10312","url":null,"abstract":"\u0000The stunt nematode species, Tylenchorhynchus annulatus (Cassidy, 1930) Golden, 1971, is a widely distributed plant parasite found associated with various major agricultural crops. In the current work, a population of T. annulatus detected from a sugarcane field in Everglades, Florida, USA, was morphologically and molecularly characterised. A comparative study was also done including the stunt nematode populations identified morphologically and molecularly by different research groups as T. agri, T. annulatus or T. crassicaudatus from China, Indonesia, Iran, Korea, Niger, Nigeria, Tanzania and the USA, revealing highly similar morphology and overlapping morphometric data among the populations. However, these populations were found separated into two maximally supported clades in phylogenetic trees based on rRNA gene sequences (28S and ITS). One clade comprised populations from China, Indonesia, Iran, Nigeria, South Korea, Tanzania and the USA, and the other clade only populations from the USA. This study also strongly supported the view that T. crassicaudatus is a junior synonym of T. annulatus.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139853109","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A taxonomic update on Tylenchorhynchus annulatus (Nematoda: Dolichodoridae), a widely distributed stunt nematode species","authors":"Phougeishangbam Rolish Singh, A. Hajihassani","doi":"10.1163/15685411-bja10312","DOIUrl":"https://doi.org/10.1163/15685411-bja10312","url":null,"abstract":"\u0000The stunt nematode species, Tylenchorhynchus annulatus (Cassidy, 1930) Golden, 1971, is a widely distributed plant parasite found associated with various major agricultural crops. In the current work, a population of T. annulatus detected from a sugarcane field in Everglades, Florida, USA, was morphologically and molecularly characterised. A comparative study was also done including the stunt nematode populations identified morphologically and molecularly by different research groups as T. agri, T. annulatus or T. crassicaudatus from China, Indonesia, Iran, Korea, Niger, Nigeria, Tanzania and the USA, revealing highly similar morphology and overlapping morphometric data among the populations. However, these populations were found separated into two maximally supported clades in phylogenetic trees based on rRNA gene sequences (28S and ITS). One clade comprised populations from China, Indonesia, Iran, Nigeria, South Korea, Tanzania and the USA, and the other clade only populations from the USA. This study also strongly supported the view that T. crassicaudatus is a junior synonym of T. annulatus.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139793055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mating sub-behaviours in Bursaphelenchus xylophilus on agar and evidence for female cooperation","authors":"Kentaro Doi, R. Shinya","doi":"10.1163/15685411-bja10310","DOIUrl":"https://doi.org/10.1163/15685411-bja10310","url":null,"abstract":"\u0000The pine wood nematode, Bursaphelenchus xylophilus, is the cause of pine wilt disease and reproduces by copulation within host pine trees. Female mate selection in B. xylophilus mating behaviour has been reported but definitive evidence is lacking. Furthermore, while the mating behaviour of the free-living nematode Caenorhabditis elegans on agar has been well understood, the mating behaviour of B. xylophilus on agar has not been studied in detail, and the differences in their characteristics remain unclear. Here, we addressed these knowledge gaps by observing B. xylophilus mating behaviour on agar. We identified six primary mating sub-behaviours in B. xylophilus males. Comparative analysis with C. elegans revealed distinct differences in the sequence of mating stages. Notably, B. xylophilus males actively searched for the female’s vulva during the wrapping stage, whereas females exhibited back-and-forth locomotion to align the male spicule with the vulva location. Additionally, we conducted mating assays using anaesthetised female nematodes to evaluate the female’s role in the mating behaviours of B. xylophilus. The mating duration increased significantly when females were anaesthetised, and the probabilities of reaching the wrapping and vulva location stages were reduced. Therefore, B. xylophilus females actively cooperate in mating behaviours. Our findings highlight unique aspects of mating behaviours in B. xylophilus and provide insights concerning differences in mating behaviours between B. xylophilus and C. elegans.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139791878","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of allelic Mi-1.2 dosage effects on levels of resistance to virulent and avirulent Meloidogyne spp. populations in some tomato rootstocks","authors":"Márcia Gabriel, Marcilene F. A. Santos, V. S. Mattos, Sheila F. Almeida, L. Boiteux, R. G. Carneiro","doi":"10.1163/15685411-bja10308","DOIUrl":"https://doi.org/10.1163/15685411-bja10308","url":null,"abstract":"\u0000The -1.2 gene confers broad-spectrum resistance to populations of at least 13 Meloidogyne species, being present in a wide range of commercial tomato (Solanum lycopersicum) cultivars. A more refined assessment of the allelic dosage effects of the -1.2 gene to virulent and avirulent Meloidogyne populations may provide relevant information for the management of the durability of the resistance under field conditions. Herein, the allelic dosage effects (homozygous vs heterozygous at the -1.2 locus) on the phenotypic expression of resistance were evaluated against one -1.2-virulent and six avirulent Meloidogyne spp. populations. Seven tomato rootstocks with distinct allelic conditions at the -1.2 locus and one susceptible control (‘Santa Clara’) were used in the present study. Significant dosage effects of -1.2 alleles in reducing the reproduction factors (RF) were observed, but restricted to the avirulent Meloidogyne populations. Homozygous resistant (-1.2/-1.2) cultivars, except TD1, prevented reproduction of almost avirulent Meloidogyne spp. populations in contrast with the heterozygous allele combination (-1.2/-1.2), which allowed a certain level of nematode reproduction. The efficiency and durability of the -1.2 gene depend on its proper management under commercial field conditions. Heterozygous (-1.2/-1.2) plants will increase the population of Meloidogyne spp., with no drastic reduction as occurring in the case of homozygous resistant, and they allow a small reproduction of more adapted sub-populations of the nematode, which might increase over time. Therefore, our results strongly indicated that the employment (whenever possible) of hybrids carrying the double dosage of the -1.2 gene would reduce the potential of high nematode populations in plants with this allelic configuration.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139850961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Single nucleotide polymorphism (SNP) marker-assisted breeding of Heterorhabditis bacteriophora for improvement of reproductive potential and stress tolerance","authors":"Christopher Ogaya, Michelle Ann B. Diano, Innocent Hategekimana, Verena Dörfler, Carlos Molina, Ralf-Udo Ehlers","doi":"10.1163/15685411-bja10307","DOIUrl":"https://doi.org/10.1163/15685411-bja10307","url":null,"abstract":"\u0000The entomopathogenic nematode (EPN), Heterorhabditis bacteriophora, is an efficient biological control agent against several economically important insect pests. Recent research has assessed the possibility to correlate desired beneficial traits with genotype data to pave a way for marker-assisted breeding approaches. A collection of H. bacteriophora WT inbred lines has been phenotyped in this framework for stress- and virulence-related traits. However, these traits are rarely combined in a single line. Thus, unifying these traits in commercial strains is of high priority. This investigation unified beneficial traits in hybrid pools through marker-assisted breeding using single nucleotide polymorphisms (SNPs) associated with reproductive potential, longevity, virulence and cold tolerance. Recombinant inbred lines (RILs) generated from a cross between a stress tolerant WT inbred line (XX21) and a line high in in vitro reproduction potential (IL3) were genotyped via SeqSNP and screened for SNP markers associated with beneficial traits. Thereafter, a genotypic pool (X21L3) comprising 22 ILs was formed. The X21L3 pool was subsequently evaluated for the target traits in comparison with the cross parents and a commercial strain HB4. An improvement of oxidative stress tolerance at 2°C (cold tolerance) was recorded with X21L3 surviving 1 day longer than the best performing parent (XX21). The hybrid pool also survived 1 day longer than the least performing parent IL3 for the trait longevity at 25°C under oxidative stress conditions. A higher dauer juvenile (DJ) recovery (58%) and DJ yield (209 000 DJ ml−1) than the least performing parent XX21 was recorded for the pool. The storage stability in diatomaceous earth formulation at 2°C and 7.5°C was also improved by 2 and 5 days, respectively, in comparison to the least performing parent XX21. This study depicts the potential of precision marker-assisted breeding for beneficial trait improvement of H. bacteriophora.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139800345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}