Pub Date : 2023-02-01DOI: 10.1163/15685411-bja10221
J. Gu, Yiwu Fang, Xinxin Ma, K. Guo
Pseudaphelenchus chunanensis n. sp. was isolated in branches of Pinus massoniana from eastern China. The new species is characterised by very short males (402 (360-452) μm) and females (470 (397-540) μm), three incisures in the lateral field, slender stylet with small but conspicuous basal knobs, excretory pore located at the level of anterior margin of the metacorpus or more anterior. Male spicules paired, thorn-like, separate, condylus truncate, sometimes broadly rounded, rostrum conical or triangular with bluntly pointed tip, calomus smoothly tapering together with lamina, thin and strongly arcuate in middle then tapering towards bluntly pointed distal tip, cucullus absent. A long and narrow bursa surrounds the entire tail but inconspicuous in most males. Conical tail bluntly rounded but sometimes has a short mucron. Female tail conical, smoothly tapering and slightly ventrally bent in distal part of tail, terminus fine or bluntly pointed. It is typologically different from six known Pseudaphelenchus species, and detailed phylogenetic analysis based on partial 18S ribosomal DNA (rDNA), internal transcribed spacer (ITS) and the D2-D3 region of 28S rDNA sequences further confirm this nematode as a new species.
{"title":"Pseudaphelenchus chunanensis n. sp. (Tylenchina: Aphelenchoididae) found in Pinus massoniana from China","authors":"J. Gu, Yiwu Fang, Xinxin Ma, K. Guo","doi":"10.1163/15685411-bja10221","DOIUrl":"https://doi.org/10.1163/15685411-bja10221","url":null,"abstract":"\u0000Pseudaphelenchus chunanensis n. sp. was isolated in branches of Pinus massoniana from eastern China. The new species is characterised by very short males (402 (360-452) μm) and females (470 (397-540) μm), three incisures in the lateral field, slender stylet with small but conspicuous basal knobs, excretory pore located at the level of anterior margin of the metacorpus or more anterior. Male spicules paired, thorn-like, separate, condylus truncate, sometimes broadly rounded, rostrum conical or triangular with bluntly pointed tip, calomus smoothly tapering together with lamina, thin and strongly arcuate in middle then tapering towards bluntly pointed distal tip, cucullus absent. A long and narrow bursa surrounds the entire tail but inconspicuous in most males. Conical tail bluntly rounded but sometimes has a short mucron. Female tail conical, smoothly tapering and slightly ventrally bent in distal part of tail, terminus fine or bluntly pointed. It is typologically different from six known Pseudaphelenchus species, and detailed phylogenetic analysis based on partial 18S ribosomal DNA (rDNA), internal transcribed spacer (ITS) and the D2-D3 region of 28S rDNA sequences further confirm this nematode as a new species.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46748157","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}
Pub Date : 2023-02-01DOI: 10.1163/15685411-bja10222
Qi Zhang, H. Ji, F. Guo, Xue Qing, Hongmei Li
Trachactinolaimus nanjingensis n. sp. isolated from mosses at the Yangshan Quarry Park in Nanjing, P.R. China, is described. It is characterised by 3.01 (2.64-3.42) mm long female and 2.84 (2.50-3.22) mm long male, four onchia with numerous mural denticles (>100), vulva with a transverse slit, 15-19 contiguous ventromedian supplements, spicules length of 61.5 (54.6-64.3) μm, and female and male both having long tail, with c′ values equal to 5.0-9.2 and 2.3-3.5, respectively. The new species was morphologically compared with T. brevicaudatus, T. dominicus, T. montanus and T. radulatus. The sequences of 18S and 28S rRNA genes of the new species were obtained using regular PCR amplification, while the ITS and mtCOI sequences were extracted from the whole genome sequencing assembly. The phylogenetic relationships of the new species were reconstructed using 18S and 28S sequences and the status of the new species was discussed. The 18S and 28S sequences of a population of genus Westindicus recovered during the present study were also obtained. This is the first time to present the ITS and mtCOI sequences of family Actinolaimidae.
{"title":"Morphological and molecular characterisation of Trachactinolaimus nanjingensis n. sp. (Dorylaimida: Actinolaimidae) from Nanjing, China","authors":"Qi Zhang, H. Ji, F. Guo, Xue Qing, Hongmei Li","doi":"10.1163/15685411-bja10222","DOIUrl":"https://doi.org/10.1163/15685411-bja10222","url":null,"abstract":"\u0000Trachactinolaimus nanjingensis n. sp. isolated from mosses at the Yangshan Quarry Park in Nanjing, P.R. China, is described. It is characterised by 3.01 (2.64-3.42) mm long female and 2.84 (2.50-3.22) mm long male, four onchia with numerous mural denticles (>100), vulva with a transverse slit, 15-19 contiguous ventromedian supplements, spicules length of 61.5 (54.6-64.3) μm, and female and male both having long tail, with c′ values equal to 5.0-9.2 and 2.3-3.5, respectively. The new species was morphologically compared with T. brevicaudatus, T. dominicus, T. montanus and T. radulatus. The sequences of 18S and 28S rRNA genes of the new species were obtained using regular PCR amplification, while the ITS and mtCOI sequences were extracted from the whole genome sequencing assembly. The phylogenetic relationships of the new species were reconstructed using 18S and 28S sequences and the status of the new species was discussed. The 18S and 28S sequences of a population of genus Westindicus recovered during the present study were also obtained. This is the first time to present the ITS and mtCOI sequences of family Actinolaimidae.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45988401","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}
Pub Date : 2023-01-30DOI: 10.1163/15685411-bja10220
N. Sharma, Kanika Khanna, Shivam Jasrotia, Deepak Kumar, R. Bhardwaj, P. Ohri
Plant-parasitic nematodes are devastating phytopathogens that cause substantial economic losses in the agricultural sector. There are numerous management measures available to reduce the threat posed by plant-parasitic nematodes. One of the most effective management strategies is the use of synthetic chemical nematicides. However, many of these chemicals negatively impact the environment and health of non-target organisms, so there is great urgency for finding new environmentally safe and sustainable approaches for managing plant-parasitic nematodes. Plant roots release numerous metabolites that possess defensive properties; thus, it is imperative to understand the root-regulated interactions among plants and nematodes that form the basis for managing plant-parasitic nematodes. The present review focuses on the root metabolites and chemical agents that serve as attractants, repellents, stimulators, or inhibitors for nematodes. They influence plant resistance by modifying plant physiology to resist nematodes and can also inhibit nematode growth and development by secreting antinematode chemicals. The ultimate goal of this review is to focus mainly on the current state of knowledge on the interaction between plant roots and the potential of these compounds in management of plant-parasitic nematodes.
{"title":"Metabolites and chemical agents in the plant roots: an overview of their use in plant-parasitic nematode management","authors":"N. Sharma, Kanika Khanna, Shivam Jasrotia, Deepak Kumar, R. Bhardwaj, P. Ohri","doi":"10.1163/15685411-bja10220","DOIUrl":"https://doi.org/10.1163/15685411-bja10220","url":null,"abstract":"\u0000Plant-parasitic nematodes are devastating phytopathogens that cause substantial economic losses in the agricultural sector. There are numerous management measures available to reduce the threat posed by plant-parasitic nematodes. One of the most effective management strategies is the use of synthetic chemical nematicides. However, many of these chemicals negatively impact the environment and health of non-target organisms, so there is great urgency for finding new environmentally safe and sustainable approaches for managing plant-parasitic nematodes. Plant roots release numerous metabolites that possess defensive properties; thus, it is imperative to understand the root-regulated interactions among plants and nematodes that form the basis for managing plant-parasitic nematodes. The present review focuses on the root metabolites and chemical agents that serve as attractants, repellents, stimulators, or inhibitors for nematodes. They influence plant resistance by modifying plant physiology to resist nematodes and can also inhibit nematode growth and development by secreting antinematode chemicals. The ultimate goal of this review is to focus mainly on the current state of knowledge on the interaction between plant roots and the potential of these compounds in management of plant-parasitic nematodes.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46282560","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}
Pub Date : 2023-01-25DOI: 10.1163/15685411-bja10224
Phougeishangbam Rolish Singh, A. Aseffa, Beira-Hailu Meressa, M. Couvreur, G. Karssen, W. Bert
A study of coffee rhizospheres collected from six coffee fields in the Gera and Gomma districts of Jimma Zone, southwest Ethiopia, revealed the presence of 12 genera of plant-parasitic nematodes, including Belonolaimus, Criconemoides, Cryphodera, Discocriconemella, Helicotylenchus, Longidorus, Ogma, Paratylenchus, Rotylenchus, Scutellonema, Tylenchorhynchus and Xiphinema. The genera Criconemoides, Helicotylenchus, Longidorus, Paratylenchus, Tylenchorhynchus and Xiphinema were the most prevalent, detected in all soil samples with up to 1590 individuals 100 ml−1 soil for Cryphodera. Morphological and molecular analysis of three genera with higher densities revealed a single species of an unknown Cryphodera sp., Paratylenchus leptos and Tylenchorhynchus cf. zeae occurring in all soil samples. Cryphodera is reported for the first time in Africa. Molecular analyses also revealed the presence of Xiphinema citricolum and several unknown species comprising one Discocriconemella sp., one Paratylenchus sp., four Helicotylenchus spp., two Ogma spp., one Rotylenchus sp. and three Xiphinema spp. In total, 32 partial 18S, 74 D2-D3 of 28S, three ITS sequences of ribosomal DNA and 24 partial mitochondrial COI gene sequences of 16 nematode species were generated. This study demonstrates that the identities of several potentially harmful nematodes are not well known, even in relation to highly important crops such as coffee.
{"title":"Molecular and morphological characterisation of some arabica coffee-associated parasitic nematodes in Gera and Gomma districts of southwest Ethiopia","authors":"Phougeishangbam Rolish Singh, A. Aseffa, Beira-Hailu Meressa, M. Couvreur, G. Karssen, W. Bert","doi":"10.1163/15685411-bja10224","DOIUrl":"https://doi.org/10.1163/15685411-bja10224","url":null,"abstract":"\u0000A study of coffee rhizospheres collected from six coffee fields in the Gera and Gomma districts of Jimma Zone, southwest Ethiopia, revealed the presence of 12 genera of plant-parasitic nematodes, including Belonolaimus, Criconemoides, Cryphodera, Discocriconemella, Helicotylenchus, Longidorus, Ogma, Paratylenchus, Rotylenchus, Scutellonema, Tylenchorhynchus and Xiphinema. The genera Criconemoides, Helicotylenchus, Longidorus, Paratylenchus, Tylenchorhynchus and Xiphinema were the most prevalent, detected in all soil samples with up to 1590 individuals 100 ml−1 soil for Cryphodera. Morphological and molecular analysis of three genera with higher densities revealed a single species of an unknown Cryphodera sp., Paratylenchus leptos and Tylenchorhynchus cf. zeae occurring in all soil samples. Cryphodera is reported for the first time in Africa. Molecular analyses also revealed the presence of Xiphinema citricolum and several unknown species comprising one Discocriconemella sp., one Paratylenchus sp., four Helicotylenchus spp., two Ogma spp., one Rotylenchus sp. and three Xiphinema spp. In total, 32 partial 18S, 74 D2-D3 of 28S, three ITS sequences of ribosomal DNA and 24 partial mitochondrial COI gene sequences of 16 nematode species were generated. This study demonstrates that the identities of several potentially harmful nematodes are not well known, even in relation to highly important crops such as coffee.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44564736","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}
Pub Date : 2023-01-25DOI: 10.1163/15685411-bja10218
Antoinette P. Malan, Rinus Knoetze, Caro Kapp, Louwrens R. Tiedt
Summary Steinernema bakwenae n. sp. isolate SF857 has been isolated from a soil sample from the North West province of South Africa. The infective juveniles were isolated using Cobb’s decanting and sieving method, hand-picked from the nematode population and inoculated directly onto wax moth larvae. Morphological and molecular characterisation provides evidence for placing the new species in the Khoisanae -clade, adding a fifth member to this all-African clade. The new species is characterised by the following morphological features: third-stage infective juveniles with a body length of 1106 (1013-1233) μ m, a distance from the anterior end to the excretory pore of 90 (81-103) μ m, and a tail length of 87 (76-103) μ m. The first-generation males can be recognised by a spicule length of 80 (66-89) μ m and by a gubernaculum length of 51 (44-56) μ m. The new species was confirmed by means of crossbreeding and characterised by means of sequences of the internal transcribed spacer (ITS), the partial 28S regions (D2-D3) of the ribosomal DNA and the mitochondrial cytochrome oxidase subunit (COI). Phylogenetic analyses show that S. innovationi and S. tophus are the closest relatives to S. bakwenae n. sp. in the Khoisanae -clade.
{"title":"Steinernema bakwenae n. sp. (Rhabditida: Steinernematidae), a new entomopathogenic nematode from South Africa","authors":"Antoinette P. Malan, Rinus Knoetze, Caro Kapp, Louwrens R. Tiedt","doi":"10.1163/15685411-bja10218","DOIUrl":"https://doi.org/10.1163/15685411-bja10218","url":null,"abstract":"Summary Steinernema bakwenae n. sp. isolate SF857 has been isolated from a soil sample from the North West province of South Africa. The infective juveniles were isolated using Cobb’s decanting and sieving method, hand-picked from the nematode population and inoculated directly onto wax moth larvae. Morphological and molecular characterisation provides evidence for placing the new species in the Khoisanae -clade, adding a fifth member to this all-African clade. The new species is characterised by the following morphological features: third-stage infective juveniles with a body length of 1106 (1013-1233) μ m, a distance from the anterior end to the excretory pore of 90 (81-103) μ m, and a tail length of 87 (76-103) μ m. The first-generation males can be recognised by a spicule length of 80 (66-89) μ m and by a gubernaculum length of 51 (44-56) μ m. The new species was confirmed by means of crossbreeding and characterised by means of sequences of the internal transcribed spacer (ITS), the partial 28S regions (D2-D3) of the ribosomal DNA and the mitochondrial cytochrome oxidase subunit (COI). Phylogenetic analyses show that S. innovationi and S. tophus are the closest relatives to S. bakwenae n. sp. in the Khoisanae -clade.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":"37 34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135998055","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}
Pub Date : 2023-01-25DOI: 10.1163/15685411-bja10225
Bashiy Akol, Qiuling Huang, Borong Lin, K. Zhuo
Pseudaphelenchus is considered an intermediate between tylenchids and Aphelenchoididae because it has both a tylench-like bursa and aphelench-like pharynx. Three nematode populations within this genus representing two new species, P. guangdongensis n. sp. and P. paraguangdongensis n. sp., were discovered from pine trees in Guangdong province, China. P. guangdongensis n. sp. most closely resembles P. vindai due to the possession of three lines in their lateral fields, whereas P. paraguangdongensis n. sp. is most like P. yukiae because they share a four-lined field. Morphological and morphometric differences of these two new species and similar species are discussed. Additionally, molecular phylogenetic trees inferred from rRNA small subunit and D2-D3 expansion domains of the rRNA large subunit revealed that P. guangdongensis n. sp. and P. paraguangdongensis n. sp. are separated from all known Pseudaphelenchus species; moreover, all Pseudaphelenchus species comprise a highly supported monophyletic clade, which is basal to the family Aphelenchoididae.
假舌蝇被认为是介于舌蝇科和舌蝇科之间的一种中间体，因为它既有类似舌蝇的囊，也有类似舌蝇的咽。在广东省的松树中发现了3个线虫居群，代表2个新种:广东线虫和巴拉圭线虫。P. guangdongensis n. sp.与P. vindai最相似，因为它们的侧田有三条线，而P. paraguangdongensis n. sp.与P. yukiae最相似，因为它们共享一条四线田。讨论了这两个新种和相似种在形态学和形态计量学上的差异。此外，从rRNA小亚基和rRNA大亚基的D2-D3扩展域推断的分子系统进化树显示，广东p.g andonsis n. sp.和巴拉圭p.p angdonsis n. sp.与所有已知的伪螺旋藻属物种是分离的;此外，所有假螺属物种都包含一个高度支持的单系分支，它是假螺科的基础。
{"title":"Two new species of Pseudaphelenchus (Aphelenchoididae: Tylaphelenchinae) isolated from pine wood in Guangdong Province, China","authors":"Bashiy Akol, Qiuling Huang, Borong Lin, K. Zhuo","doi":"10.1163/15685411-bja10225","DOIUrl":"https://doi.org/10.1163/15685411-bja10225","url":null,"abstract":"\u0000Pseudaphelenchus is considered an intermediate between tylenchids and Aphelenchoididae because it has both a tylench-like bursa and aphelench-like pharynx. Three nematode populations within this genus representing two new species, P. guangdongensis n. sp. and P. paraguangdongensis n. sp., were discovered from pine trees in Guangdong province, China. P. guangdongensis n. sp. most closely resembles P. vindai due to the possession of three lines in their lateral fields, whereas P. paraguangdongensis n. sp. is most like P. yukiae because they share a four-lined field. Morphological and morphometric differences of these two new species and similar species are discussed. Additionally, molecular phylogenetic trees inferred from rRNA small subunit and D2-D3 expansion domains of the rRNA large subunit revealed that P. guangdongensis n. sp. and P. paraguangdongensis n. sp. are separated from all known Pseudaphelenchus species; moreover, all Pseudaphelenchus species comprise a highly supported monophyletic clade, which is basal to the family Aphelenchoididae.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44921776","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}
Pub Date : 2023-01-25DOI: 10.1163/156854106777998728
A. Malan, R. Knoetze, C. Kapp, L. Tiedt
Steinernema bakwenae n. sp. isolate SF857 has been isolated from a soil sample from the North West province of South Africa. The infective juveniles were isolated using Cobb’s decanting and sieving method, hand-picked from the nematode population and inoculated directly onto wax moth larvae. Morphological and molecular characterisation provides evidence for placing the new species in the Khoisanae-clade, adding a fifth member to this all-African clade. The new species is characterised by the following morphological features: third-stage infective juveniles with a body length of 1106 (1013-1233) μm, a distance from the anterior end to the excretory pore of 90 (81-103) μm, and a tail length of 87 (76-103) μm. The first-generation males can be recognised by a spicule length of 80 (66-89) μm and by a gubernaculum length of 51 (44-56) μm. The new species was confirmed by means of crossbreeding and characterised by means of sequences of the internal transcribed spacer (ITS), the partial 28S regions (D2-D3) of the ribosomal DNA and the mitochondrial cytochrome oxidase subunit (COI). Phylogenetic analyses show that S. innovationi and S. tophus are the closest relatives to S. bakwenae n. sp. in the Khoisanae-clade.
{"title":"Steinernema bakwenae n. sp. (Rhabditida: Steinernematidae), a new entomopathogenic nematode from South Africa","authors":"A. Malan, R. Knoetze, C. Kapp, L. Tiedt","doi":"10.1163/156854106777998728","DOIUrl":"https://doi.org/10.1163/156854106777998728","url":null,"abstract":"\u0000Steinernema bakwenae n. sp. isolate SF857 has been isolated from a soil sample from the North West province of South Africa. The infective juveniles were isolated using Cobb’s decanting and sieving method, hand-picked from the nematode population and inoculated directly onto wax moth larvae. Morphological and molecular characterisation provides evidence for placing the new species in the Khoisanae-clade, adding a fifth member to this all-African clade. The new species is characterised by the following morphological features: third-stage infective juveniles with a body length of 1106 (1013-1233) μm, a distance from the anterior end to the excretory pore of 90 (81-103) μm, and a tail length of 87 (76-103) μm. The first-generation males can be recognised by a spicule length of 80 (66-89) μm and by a gubernaculum length of 51 (44-56) μm. The new species was confirmed by means of crossbreeding and characterised by means of sequences of the internal transcribed spacer (ITS), the partial 28S regions (D2-D3) of the ribosomal DNA and the mitochondrial cytochrome oxidase subunit (COI). Phylogenetic analyses show that S. innovationi and S. tophus are the closest relatives to S. bakwenae n. sp. in the Khoisanae-clade.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1163/156854106777998728","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47325124","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}
Pub Date : 2023-01-23DOI: 10.1163/15685411-bja10219
S. A. Oliveira, S. DeWalt, P. Agudelo
Ditylenchus gallaeformans causes severe galls on above-ground parts of Miconia spp. (Melastomataceae) and has therefore been considered as a biocontrol agent against several invasive Melastome species, including Miconia crenata. To assess the feasibility of using this nematode as a biocontrol agent, we conducted glasshouse and field experiments with D. gallaeformans collected from different locations and host species and inoculated on M. crenata from different native and introduced populations. In a glasshouse experiment, nematodes collected from galls from Costa Rica induced small galls on plants from Hawaii (introduced range) but not from Costa Rica (native range). In another experiment, nematodes from Trinidad inoculated on plants from four locations in the native range and two from the introduced range induced symptoms on plants from Trinidad and Hawaii (native and introduced, respectively), but galls typically found in nature failed to occur. In addition, inoculations performed in a glasshouse and in the field in Trinidad failed to yield any galls. Considering that galls were produced inconsistently and never developed to the severity found naturally in the field, we conclude that D. gallaeformans would be an intractable biological control agent for M. crenata.
{"title":"Feasibility of Ditylenchus gallaeformans as a biological control agent for invasive Miconia crenata","authors":"S. A. Oliveira, S. DeWalt, P. Agudelo","doi":"10.1163/15685411-bja10219","DOIUrl":"https://doi.org/10.1163/15685411-bja10219","url":null,"abstract":"\u0000Ditylenchus gallaeformans causes severe galls on above-ground parts of Miconia spp. (Melastomataceae) and has therefore been considered as a biocontrol agent against several invasive Melastome species, including Miconia crenata. To assess the feasibility of using this nematode as a biocontrol agent, we conducted glasshouse and field experiments with D. gallaeformans collected from different locations and host species and inoculated on M. crenata from different native and introduced populations. In a glasshouse experiment, nematodes collected from galls from Costa Rica induced small galls on plants from Hawaii (introduced range) but not from Costa Rica (native range). In another experiment, nematodes from Trinidad inoculated on plants from four locations in the native range and two from the introduced range induced symptoms on plants from Trinidad and Hawaii (native and introduced, respectively), but galls typically found in nature failed to occur. In addition, inoculations performed in a glasshouse and in the field in Trinidad failed to yield any galls. Considering that galls were produced inconsistently and never developed to the severity found naturally in the field, we conclude that D. gallaeformans would be an intractable biological control agent for M. crenata.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43663140","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}
Pub Date : 2023-01-18DOI: 10.1163/15685411-bja10217
K. Togashi, J. Appleby, H. oloumi-Sadeghi, R. B. Malek
The pine wood nematode (PWN), Bursaphelenchus xylophilus, is the causative agent of pine wilt disease and is transmitted primarily by cerambycid adults of the genus Monochamus. It is believed to have been introduced into Japan from North America in the 1900s and confirmed to have invaded western Europe in 1999. The nematode has been devastating pine forests in invaded areas because the native pine species are susceptible. This study examined the number of PWN carried by individual M. carolinensis adults (initial PWN load) immediately after emerging from dead Pinus sylvestris and P. strobus trees in Illinois, USA. The data were compared with the initial PWN load on M. alternatus adults emerging from dead P. thunbergii trees in Japan ca 80 years after the PWN invasion. When the zero-inflated negative binomial model was fitted to the initial PWN loads it provided three results. First, the PWN exhibited clumped distributions among vectors in the PWN-M. carolinensis-P. sylvestris or P. strobus system in Illinois and the PWN-M. alternatus-P. thunbergii system in Japan. Second, there was no difference in the frequency distribution of the initial PWN load between the three disease systems. Third, the initial PWN load increased as the overwintering PWN density in wood or the adult body mass increased, whereas it decreased as the emergence date of vectors increased. Consequently, the frequency distribution of initial PWN load exhibited no evolutionary change in Japan and the initial PWN load was considered to be determined by environmental factors and conditions.
{"title":"Frequency distribution of the initial number of Bursaphelenchus xylophilus carried by adult Monochamus carolinensis in Illinois, with reference to that by M. alternatus in Japan","authors":"K. Togashi, J. Appleby, H. oloumi-Sadeghi, R. B. Malek","doi":"10.1163/15685411-bja10217","DOIUrl":"https://doi.org/10.1163/15685411-bja10217","url":null,"abstract":"\u0000The pine wood nematode (PWN), Bursaphelenchus xylophilus, is the causative agent of pine wilt disease and is transmitted primarily by cerambycid adults of the genus Monochamus. It is believed to have been introduced into Japan from North America in the 1900s and confirmed to have invaded western Europe in 1999. The nematode has been devastating pine forests in invaded areas because the native pine species are susceptible. This study examined the number of PWN carried by individual M. carolinensis adults (initial PWN load) immediately after emerging from dead Pinus sylvestris and P. strobus trees in Illinois, USA. The data were compared with the initial PWN load on M. alternatus adults emerging from dead P. thunbergii trees in Japan ca 80 years after the PWN invasion. When the zero-inflated negative binomial model was fitted to the initial PWN loads it provided three results. First, the PWN exhibited clumped distributions among vectors in the PWN-M. carolinensis-P. sylvestris or P. strobus system in Illinois and the PWN-M. alternatus-P. thunbergii system in Japan. Second, there was no difference in the frequency distribution of the initial PWN load between the three disease systems. Third, the initial PWN load increased as the overwintering PWN density in wood or the adult body mass increased, whereas it decreased as the emergence date of vectors increased. Consequently, the frequency distribution of initial PWN load exhibited no evolutionary change in Japan and the initial PWN load was considered to be determined by environmental factors and conditions.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45490868","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}
Pub Date : 2022-12-22DOI: 10.1163/15685411-bja10215
A. Bhat, A. Loulou, J. Abolafia, R. A. Machado, S. Kallel
Four populations of Acrobeloides nematodes were isolated from Tunisian soils. Based on morphological and morphometric data, two populations, TC9 and HWO, were identified as A. tricornis and the other two, TC7 and K18g, as A. bodenheimeri. Acrobeloides tricornis is distinguished from its closely related species by its high labial probolae with arcuate termini, inconspicuous post-uterine sac, and five lateral incisures, while A. bodenheimeri is distinguished from other acrobeloids by having a low and rounded labial probolae, distinct post-uterine sac, five lateral incisures, and vulva frequently with vaginal plug. The A. tricornis and A. bodenheimeri reported in this study are distinguished by the shape of labial probolae (high with acute distal part vs low and rounded), post-uterine sac (inconspicuous vs distinct), position of the reproductive system with respect to the intestine (sinistral vs dextral), vulva with vaginal plug (present vs absent) and some morphometric characters (such as body length). Further, these species were also molecularly characterised using the sequences of the D2-D3 region of the 28S rRNA gene, the 18S rRNA gene, the ITS rRNA gene, and of the mitochondrial cytochrome c oxidase subunit I (mtCO1) gene. Phylogenetic trees using ribosomal RNA gene sequences clearly separate species of the ‘Maximus’ group, but these sequences appear to be identical in several other Acrobeloides species, and thus are unlikely to be useful as molecular markers for species-level molecular identification in the genus Acrobeloides. The mtCO1 gene sequences of two A. tricornis populations differ in 58 and 64 nucleotide bases from A. varius and A. nanus, respectively, indicating that the mtCO1 gene sequences have greater phylogenetic resolving power than nuclear rRNA gene sequences, and that this gene marker can differentiate closely related species in the genus Acrobeloides.
{"title":"Comparative morphological and molecular analyses of Acrobeloides bodenheimeri and A. tricornis Cobb, 1924 (Rhabditida, Cephalobidae) from Tunisia","authors":"A. Bhat, A. Loulou, J. Abolafia, R. A. Machado, S. Kallel","doi":"10.1163/15685411-bja10215","DOIUrl":"https://doi.org/10.1163/15685411-bja10215","url":null,"abstract":"\u0000Four populations of Acrobeloides nematodes were isolated from Tunisian soils. Based on morphological and morphometric data, two populations, TC9 and HWO, were identified as A. tricornis and the other two, TC7 and K18g, as A. bodenheimeri. Acrobeloides tricornis is distinguished from its closely related species by its high labial probolae with arcuate termini, inconspicuous post-uterine sac, and five lateral incisures, while A. bodenheimeri is distinguished from other acrobeloids by having a low and rounded labial probolae, distinct post-uterine sac, five lateral incisures, and vulva frequently with vaginal plug. The A. tricornis and A. bodenheimeri reported in this study are distinguished by the shape of labial probolae (high with acute distal part vs low and rounded), post-uterine sac (inconspicuous vs distinct), position of the reproductive system with respect to the intestine (sinistral vs dextral), vulva with vaginal plug (present vs absent) and some morphometric characters (such as body length). Further, these species were also molecularly characterised using the sequences of the D2-D3 region of the 28S rRNA gene, the 18S rRNA gene, the ITS rRNA gene, and of the mitochondrial cytochrome c oxidase subunit I (mtCO1) gene. Phylogenetic trees using ribosomal RNA gene sequences clearly separate species of the ‘Maximus’ group, but these sequences appear to be identical in several other Acrobeloides species, and thus are unlikely to be useful as molecular markers for species-level molecular identification in the genus Acrobeloides. The mtCO1 gene sequences of two A. tricornis populations differ in 58 and 64 nucleotide bases from A. varius and A. nanus, respectively, indicating that the mtCO1 gene sequences have greater phylogenetic resolving power than nuclear rRNA gene sequences, and that this gene marker can differentiate closely related species in the genus Acrobeloides.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2022-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42775541","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}
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