Pub Date : 2023-08-01DOI: 10.1163/15685411-bja10266
Jorge B. S. Verssiani, Caio F. B. Souza, P. S. Santos, C. Arias, J. Cares, R. G. Carneiro
Limited information is available regarding the susceptibility or resistance of soybean cultivars to Meloidogyne enterolobii. Recently, a new race of this species was detected in Brazil parasitising cotton and soybean. This nematode has the potential to pose a problem in both of these crops, since it is pathogenic and virulent to several economically important plants that have resistance genes to other Meloidogyne species. The aim of this study was to assess the responses of EMBRAPA’s main soybean cultivars with confirmed resistance to M. incognita and M. javanica to the two races of M. enterolobii detected in Brazil. Additionally, this study aimed to characterise the aggressiveness of these nematode races. The experiments were conducted in a plastic house, in a factorial scheme with 16 soybean cultivars × two M. enterolobii races (guava and cotton), totalling 32 treatments × eight replications, and evaluated with two replications over time. Soybean sowing took place in pots containing 1.7 l of a mixture of soil, sand and Bioplant® substrate (1:1:1), previously autoclaved. Each soybean plant was inoculated with 5000 eggs of M. enterolobii. After 75 days for the first experiment, and 90 days for the second, the following variables were evaluated: gall index (GI), egg mass index (EMI), total number of eggs per g root (NEGR) and the reproduction factor (RF). Both races of M. enterolobii showed reproductive ability in all soybean genotypes (with or without known genetic resistance), albeit with moderate to low values in comparison to their reproduction on tomato plants. The race from cotton was considered statistically more aggressive than the guava population on soybean cultivars. Only ‘BRS 7180 IPRO’ was moderately resistant to both races in both experiments. In view of the importance and prospects for expansion of the soybean crop, the findings of this study contribute to a better understanding of the resistance and aggressiveness exhibited by the two races of M. enterolobii, Moreover, the study highlights the significant challenge that lies ahead in developing breeding programmes to select soybean genotypes with multiple resistance to Meloidogyne spp.
{"title":"Reaction of soybean cultivars to two races of Meloidogyne enterolobii and their aggressiveness under plastic house conditions","authors":"Jorge B. S. Verssiani, Caio F. B. Souza, P. S. Santos, C. Arias, J. Cares, R. G. Carneiro","doi":"10.1163/15685411-bja10266","DOIUrl":"https://doi.org/10.1163/15685411-bja10266","url":null,"abstract":"\u0000Limited information is available regarding the susceptibility or resistance of soybean cultivars to Meloidogyne enterolobii. Recently, a new race of this species was detected in Brazil parasitising cotton and soybean. This nematode has the potential to pose a problem in both of these crops, since it is pathogenic and virulent to several economically important plants that have resistance genes to other Meloidogyne species. The aim of this study was to assess the responses of EMBRAPA’s main soybean cultivars with confirmed resistance to M. incognita and M. javanica to the two races of M. enterolobii detected in Brazil. Additionally, this study aimed to characterise the aggressiveness of these nematode races. The experiments were conducted in a plastic house, in a factorial scheme with 16 soybean cultivars × two M. enterolobii races (guava and cotton), totalling 32 treatments × eight replications, and evaluated with two replications over time. Soybean sowing took place in pots containing 1.7 l of a mixture of soil, sand and Bioplant® substrate (1:1:1), previously autoclaved. Each soybean plant was inoculated with 5000 eggs of M. enterolobii. After 75 days for the first experiment, and 90 days for the second, the following variables were evaluated: gall index (GI), egg mass index (EMI), total number of eggs per g root (NEGR) and the reproduction factor (RF). Both races of M. enterolobii showed reproductive ability in all soybean genotypes (with or without known genetic resistance), albeit with moderate to low values in comparison to their reproduction on tomato plants. The race from cotton was considered statistically more aggressive than the guava population on soybean cultivars. Only ‘BRS 7180 IPRO’ was moderately resistant to both races in both experiments. In view of the importance and prospects for expansion of the soybean crop, the findings of this study contribute to a better understanding of the resistance and aggressiveness exhibited by the two races of M. enterolobii, Moreover, the study highlights the significant challenge that lies ahead in developing breeding programmes to select soybean genotypes with multiple resistance to Meloidogyne spp.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43849976","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 : 2023-08-01DOI: 10.1163/15685411-bja10269
S. Subbotin, C. Sainz, Carmen L. Villarroel, J. Franco
In 2022, during potato cyst nematode surveys in several departments of Bolivia, the potato cyst nematode Globodera ellingtonae Handoo et al., 2012 was detected for the first time in Bolivia from potato fields located in the Department of Tarija. Cysts and second-stage juveniles of the Bolivian populations were morphologically and morphometrically similar to those of the USA (Oregon and Idaho) and Argentina. Nine new ITS rRNA, 15 COI, 13 cytb gene sequences of G. ellingtonae from ten Bolivian populations were obtained in this study. The phylogenetic analyses of the ITS rRNA and cytb genes showed that all Bolivian sequences clustered together and formed a major clade with other G. ellingtonae sequences from Argentina, Chile and the USA. Molecular results confirmed the hypothesis that the mountain region in southern Bolivia, northwest Argentina and northern Chile could be considered as an ancient centre of origin of G. ellingtonae. The present molecular results suggested that G. ellingtonae was likely introduced into the USA from Chile, rather than from Bolivia and Argentina.
{"title":"Molecular characterisation of the potato cyst nematode, Globodera ellingtonae Handoo et al., 2012 (Tylenchida: Heteroderidae) from Bolivia","authors":"S. Subbotin, C. Sainz, Carmen L. Villarroel, J. Franco","doi":"10.1163/15685411-bja10269","DOIUrl":"https://doi.org/10.1163/15685411-bja10269","url":null,"abstract":"\u0000In 2022, during potato cyst nematode surveys in several departments of Bolivia, the potato cyst nematode Globodera ellingtonae Handoo et al., 2012 was detected for the first time in Bolivia from potato fields located in the Department of Tarija. Cysts and second-stage juveniles of the Bolivian populations were morphologically and morphometrically similar to those of the USA (Oregon and Idaho) and Argentina. Nine new ITS rRNA, 15 COI, 13 cytb gene sequences of G. ellingtonae from ten Bolivian populations were obtained in this study. The phylogenetic analyses of the ITS rRNA and cytb genes showed that all Bolivian sequences clustered together and formed a major clade with other G. ellingtonae sequences from Argentina, Chile and the USA. Molecular results confirmed the hypothesis that the mountain region in southern Bolivia, northwest Argentina and northern Chile could be considered as an ancient centre of origin of G. ellingtonae. The present molecular results suggested that G. ellingtonae was likely introduced into the USA from Chile, rather than from Bolivia and Argentina.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47838429","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 : 2023-07-11DOI: 10.1163/15685411-bja10264
Chandramani D. Waghmare, M. R. Khan, V. Somvanshi, Md Niraul Islam, Razia Sultana, Artha Kundu
A population of Ficophagus was discovered in the syconia of sacred fig (Ficus religiosa) grown in New Delhi (India). Based on morphology, morphometric characters and molecular data, we redescribed the population as Ficophagus religiosus. Here, major morphological characteristics are described in depth, with measurements of the male-female specimens’ taxonomic characters and photomicrography. Ficophagus religiosus can be easily identified by the spiral to J-spiral-shaped body, labial disc not offset, SE pore close to the base of the lip region, stylet length 17.7 (16-19) μm in males, and 19 (15-22) μm in females, a short post-uterine sac of length 8.3 μm (5-10 μm), a spicule with broad and high condylus, capitulum flat or depressed, a small bluntly rounded rostrum, the spicule tip (bluntly rounded or pointed), no cucullus, no gubernaculum, three pairs (P3, P3a, P4) of subventral caudal papillae, and broadly or bluntly rounded tail tip, without mucron. Additionally, new sequence data for the D2-D3 region of 28S rDNA (LSU) and 18S rDNA (SSU) marker genes are provided. Maximum likelihood and Bayesian methods were used to infer phylogenetic relationships of the Indian population of F. religiosus with other Ficophagus species. Phylogenetic analyses based on D2-D3 and SSU molecular markers resulted in a clear separation of F. religiosus from other Ficophagus species. The present study redescribes the species F. religiosus and provides molecular data to identify and establish phylogenetic relationships with other species.
{"title":"Molecular characterisation and redescription of Ficophagus religiosus (Bajaj & Tomar, 2014) Davies & Bartholomaeus, 2015 from Ficus religiosa in India","authors":"Chandramani D. Waghmare, M. R. Khan, V. Somvanshi, Md Niraul Islam, Razia Sultana, Artha Kundu","doi":"10.1163/15685411-bja10264","DOIUrl":"https://doi.org/10.1163/15685411-bja10264","url":null,"abstract":"\u0000A population of Ficophagus was discovered in the syconia of sacred fig (Ficus religiosa) grown in New Delhi (India). Based on morphology, morphometric characters and molecular data, we redescribed the population as Ficophagus religiosus. Here, major morphological characteristics are described in depth, with measurements of the male-female specimens’ taxonomic characters and photomicrography. Ficophagus religiosus can be easily identified by the spiral to J-spiral-shaped body, labial disc not offset, SE pore close to the base of the lip region, stylet length 17.7 (16-19) μm in males, and 19 (15-22) μm in females, a short post-uterine sac of length 8.3 μm (5-10 μm), a spicule with broad and high condylus, capitulum flat or depressed, a small bluntly rounded rostrum, the spicule tip (bluntly rounded or pointed), no cucullus, no gubernaculum, three pairs (P3, P3a, P4) of subventral caudal papillae, and broadly or bluntly rounded tail tip, without mucron. Additionally, new sequence data for the D2-D3 region of 28S rDNA (LSU) and 18S rDNA (SSU) marker genes are provided. Maximum likelihood and Bayesian methods were used to infer phylogenetic relationships of the Indian population of F. religiosus with other Ficophagus species. Phylogenetic analyses based on D2-D3 and SSU molecular markers resulted in a clear separation of F. religiosus from other Ficophagus species. The present study redescribes the species F. religiosus and provides molecular data to identify and establish phylogenetic relationships with other species.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2023-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45197894","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 : 2023-06-23DOI: 10.1163/15685411-bja10263
Mojtaba Keramat, Zeinab Mahboubi, M. R. Atighi, E. Pourjam, J. Abolafia, Saif Abdulhussin Alghanimi, M. Pedram
A new species of Ektaphelenchinae was recovered from the bark of a dead date palm (Phoenix dactylifera) tree, and from a soil sample collected from the rhizosphere of gramineous grasses in Iraq and Iran, respectively. It was assigned to the genus Ektaphelenchus mainly by the lack of a functional anus and rectum, and having a conical posterior body end (tail) in female, not ending to a filiform tip, and males lacking a bursa. The recovered populations were described based on morphological and molecular data. Ektaphelenchus phoenicis n. sp. is characterised by 346-441 μm long females, having three lines in lateral field, a 12.3-15.8 μm long stylet with wide lumen lacking basal knobs or swellings, high lip region separated from the rest of body by a depression, metacorpus elliptical with refractive valve plates almost in the middle to slightly posterior, excretory pore posterior to metacorpus, postvulval uterine sac (PUS) 9.3-14.8 μm long, usually containing sperm, posterior body end (tail) with ventrally bent distal end, males common in population with seven precloacal + cloacal + caudal papillae and slightly elevated cloacal lips under SEM, appearing as a differentiated flap-like structure under LM. The new species was morphologically compared with typologically similar species of Ektaphelenchus with a similar body size, namely: E. golestanicus, E. oleae and E. taiwanensis; a similar female posterior body end, namely: E. cupressi, E. kanzakii, E. prolobos and E. riograndensis; and E. goffarti having a similar postcloacal structure. The phylogenetic relationships of the new species with other relevant genera and species were reconstructed using near full length sequences of small and D2-D3 expansion segments of large subunit (SSU and LSU D2-D3) rDNA. In both inferred phylogenies, the newly generated sequences of Ektaphelenchus phoenicis n. sp. occupied a placement inside a maximally supported clade including sequences of three genera Ektaphelenchus, Ektaphelenchoides and Devibursaphelenchus.
{"title":"Description of Ektaphelenchus phoenicis n. sp. (Rhabditida: Ektaphelenchinae), a morphological and molecular phylogenetic study","authors":"Mojtaba Keramat, Zeinab Mahboubi, M. R. Atighi, E. Pourjam, J. Abolafia, Saif Abdulhussin Alghanimi, M. Pedram","doi":"10.1163/15685411-bja10263","DOIUrl":"https://doi.org/10.1163/15685411-bja10263","url":null,"abstract":"\u0000A new species of Ektaphelenchinae was recovered from the bark of a dead date palm (Phoenix dactylifera) tree, and from a soil sample collected from the rhizosphere of gramineous grasses in Iraq and Iran, respectively. It was assigned to the genus Ektaphelenchus mainly by the lack of a functional anus and rectum, and having a conical posterior body end (tail) in female, not ending to a filiform tip, and males lacking a bursa. The recovered populations were described based on morphological and molecular data. Ektaphelenchus phoenicis n. sp. is characterised by 346-441 μm long females, having three lines in lateral field, a 12.3-15.8 μm long stylet with wide lumen lacking basal knobs or swellings, high lip region separated from the rest of body by a depression, metacorpus elliptical with refractive valve plates almost in the middle to slightly posterior, excretory pore posterior to metacorpus, postvulval uterine sac (PUS) 9.3-14.8 μm long, usually containing sperm, posterior body end (tail) with ventrally bent distal end, males common in population with seven precloacal + cloacal + caudal papillae and slightly elevated cloacal lips under SEM, appearing as a differentiated flap-like structure under LM. The new species was morphologically compared with typologically similar species of Ektaphelenchus with a similar body size, namely: E. golestanicus, E. oleae and E. taiwanensis; a similar female posterior body end, namely: E. cupressi, E. kanzakii, E. prolobos and E. riograndensis; and E. goffarti having a similar postcloacal structure. The phylogenetic relationships of the new species with other relevant genera and species were reconstructed using near full length sequences of small and D2-D3 expansion segments of large subunit (SSU and LSU D2-D3) rDNA. In both inferred phylogenies, the newly generated sequences of Ektaphelenchus phoenicis n. sp. occupied a placement inside a maximally supported clade including sequences of three genera Ektaphelenchus, Ektaphelenchoides and Devibursaphelenchus.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2023-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49071934","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 : 2023-06-20DOI: 10.1163/15685411-bja10262
L. Taning, Eleni K. Tafes, S. Fleerakkers, L. Lippens, E. Formesyn, L. Tirry, W. Wesemael
Management strategies applied to reduce Meloidogyne chitwoodi populations below economic damage threshold depend strongly on measures taken during the intercrop period. Therefore, this study evaluated the reproductive potentials of M. chitwoodi on different cultivars of cover crops. Twenty-two different cultivars were evaluated against M. chitwoodi at low and high initial inoculum density in a pot experiment under controlled conditions. Fallow was used as control. Based on the reproductive factor, the cover crops were classified under five different categories: Non-host, Poor host, Maintenance host, Good host and Excellent host. In this study, at both low (10 second-stage juveniles (J2) 100 cm−3 soil) and high (100 J2 100 cm−3 soil) initial inoculum density of M. chitwoodi, fodder radish ‘Maximus’, ‘Contra’, ‘Dacapo’ and ‘Defender’, Italian ryegrass ‘Meroa’, rye ‘Matador’ and bird’s foot trefoil ‘Barguay’, ‘Franco’ and ‘Lotar’ were considered poor hosts reducing the M. chitwoodi population in the pot test based on reproductive factor (RF) values. Field experiments were carried out that confirmed most of our results in the pot experiments. However, the field experiments showed that the rotations in which the cover crops are implemented are influenced by weather conditions, previous crop grown, their growing period and initial population densities. Based on our findings, selected non- and poor-host cover crops could be recommended for integrated management of M. chitwoodi.
{"title":"Impact of cover crops on population density of the root-knot nematode Meloidogyne chitwoodi","authors":"L. Taning, Eleni K. Tafes, S. Fleerakkers, L. Lippens, E. Formesyn, L. Tirry, W. Wesemael","doi":"10.1163/15685411-bja10262","DOIUrl":"https://doi.org/10.1163/15685411-bja10262","url":null,"abstract":"\u0000Management strategies applied to reduce Meloidogyne chitwoodi populations below economic damage threshold depend strongly on measures taken during the intercrop period. Therefore, this study evaluated the reproductive potentials of M. chitwoodi on different cultivars of cover crops. Twenty-two different cultivars were evaluated against M. chitwoodi at low and high initial inoculum density in a pot experiment under controlled conditions. Fallow was used as control. Based on the reproductive factor, the cover crops were classified under five different categories: Non-host, Poor host, Maintenance host, Good host and Excellent host. In this study, at both low (10 second-stage juveniles (J2) 100 cm−3 soil) and high (100 J2 100 cm−3 soil) initial inoculum density of M. chitwoodi, fodder radish ‘Maximus’, ‘Contra’, ‘Dacapo’ and ‘Defender’, Italian ryegrass ‘Meroa’, rye ‘Matador’ and bird’s foot trefoil ‘Barguay’, ‘Franco’ and ‘Lotar’ were considered poor hosts reducing the M. chitwoodi population in the pot test based on reproductive factor (RF) values. Field experiments were carried out that confirmed most of our results in the pot experiments. However, the field experiments showed that the rotations in which the cover crops are implemented are influenced by weather conditions, previous crop grown, their growing period and initial population densities. Based on our findings, selected non- and poor-host cover crops could be recommended for integrated management of M. chitwoodi.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2023-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41307995","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 : 2023-06-15DOI: 10.1163/15685411-bja10261
N. Kanzaki, Yuta Fujimori, K. Hamaguchi
{"title":"Isolation of Sheraphelenchus sucus from Epuraea (Haptoncus) ocularis collected from an Anoplolepis gracilipes nest in Okinawa, Japan","authors":"N. Kanzaki, Yuta Fujimori, K. Hamaguchi","doi":"10.1163/15685411-bja10261","DOIUrl":"https://doi.org/10.1163/15685411-bja10261","url":null,"abstract":"","PeriodicalId":18928,"journal":{"name":"Nematology","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2023-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49242859","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 : 2023-06-12DOI: 10.1163/15685411-bja10260
J. Gu, Xinxin Ma, P. Castillo, M. Munawar
The present study describes a new Ditylenchus species, isolated from the bulbs of the Persian buttercup (Ranunculus asiaticus L.) imported from Israel at the Ningbo plant quarantine lab, Ningbo, P.R. China. Ditylenchus israelensis n. sp. is an amphimictic species; females have six incisures in the lateral field, a long and slim body, a delicate, short stylet (7-8 μm) with small and rounded knobs, excretory pore in the anterior region of the basal pharyngeal bulb, posteriorly located vulva (V = 78.6-83.1), a short PUS (15.0-24.0 μm), and a long conical tail with a pointed terminus. Males are similar to females in general morphology and have 14.0-18.0 μm long spicules. The new species was also characterised molecularly using 18S, ITS and D2-D3 expansion segments of 28S rDNA genes. Our phylogenetic analyses showed its independent position among available Ditylenchus species and a close phylogenetic affinity with D. valveus. Several Ditylenchus species are regulated pests; their detection in a given sample can implement quarantine measures. However, to our knowledge D. israelensis n. sp. did not cause any damage to the R. asiaticus bulbs. In addition, future studies regarding fecundity and host association may shed some light on the pathogenic potential of D. israelensis n. sp.
{"title":"Detection and description of Ditylenchus israelensis n. sp. (Nematoda: Anguinidae) from bulbs of the Persian buttercup (Ranunculus asiaticus L.)","authors":"J. Gu, Xinxin Ma, P. Castillo, M. Munawar","doi":"10.1163/15685411-bja10260","DOIUrl":"https://doi.org/10.1163/15685411-bja10260","url":null,"abstract":"\u0000The present study describes a new Ditylenchus species, isolated from the bulbs of the Persian buttercup (Ranunculus asiaticus L.) imported from Israel at the Ningbo plant quarantine lab, Ningbo, P.R. China. Ditylenchus israelensis n. sp. is an amphimictic species; females have six incisures in the lateral field, a long and slim body, a delicate, short stylet (7-8 μm) with small and rounded knobs, excretory pore in the anterior region of the basal pharyngeal bulb, posteriorly located vulva (V = 78.6-83.1), a short PUS (15.0-24.0 μm), and a long conical tail with a pointed terminus. Males are similar to females in general morphology and have 14.0-18.0 μm long spicules. The new species was also characterised molecularly using 18S, ITS and D2-D3 expansion segments of 28S rDNA genes. Our phylogenetic analyses showed its independent position among available Ditylenchus species and a close phylogenetic affinity with D. valveus. Several Ditylenchus species are regulated pests; their detection in a given sample can implement quarantine measures. However, to our knowledge D. israelensis n. sp. did not cause any damage to the R. asiaticus bulbs. In addition, future studies regarding fecundity and host association may shed some light on the pathogenic potential of D. israelensis n. sp.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2023-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48946039","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 : 2023-06-01DOI: 10.1163/15685411-bja10254
E. Shokoohi, J. Abolafia, A. Swart, N. Moyo, J. Eisenback
During a survey of soil nematodes in 2022, a free-living bacterivorous nematode, described here as Mesorhabditis sudafricana n. sp., was discovered in association with kikuyu grass in Limpopo Province, South Africa. The new species was distinguished by a relatively long body (716-815 μm in females and 605-689 μm in males), long spicules (61-66 μm), and gubernaculum (22-24 μm) and a short tail (15-20 μm in females and 18-21 μm in males). The vulva is positioned posteriad (93-95% of body length), and the distance from vulva to anus is long (1.5-1.9 times tail length). Additionally, the new species bears seven lateral field incisures and a peloderan bursa with the genital papillae in arrangement 2/3+ph+1+3, being two precloacal and eight postcloacal. The 28S rDNA BlastN showed 94% similarity with an unidentified Mesorhabditis (deposited as Bursilla (EF990722). By contrast, the ITS rDNA BlastN showed 82% similarity with Mesorhabditis paucipapillata (MT710243). The phylogenetic analysis of 28S and ITS rDNA placed the new species separately from the other Mesorhabditis. Description, measurements, illustrations and SEM micrographs for M. sudafricana n. sp. are provided.
{"title":"Mesorhabditis sudafricana n. sp. (Rhabditida, Mesorhabditidae), a new species with a short tail from South Africa","authors":"E. Shokoohi, J. Abolafia, A. Swart, N. Moyo, J. Eisenback","doi":"10.1163/15685411-bja10254","DOIUrl":"https://doi.org/10.1163/15685411-bja10254","url":null,"abstract":"\u0000During a survey of soil nematodes in 2022, a free-living bacterivorous nematode, described here as Mesorhabditis sudafricana n. sp., was discovered in association with kikuyu grass in Limpopo Province, South Africa. The new species was distinguished by a relatively long body (716-815 μm in females and 605-689 μm in males), long spicules (61-66 μm), and gubernaculum (22-24 μm) and a short tail (15-20 μm in females and 18-21 μm in males). The vulva is positioned posteriad (93-95% of body length), and the distance from vulva to anus is long (1.5-1.9 times tail length). Additionally, the new species bears seven lateral field incisures and a peloderan bursa with the genital papillae in arrangement 2/3+ph+1+3, being two precloacal and eight postcloacal. The 28S rDNA BlastN showed 94% similarity with an unidentified Mesorhabditis (deposited as Bursilla (EF990722). By contrast, the ITS rDNA BlastN showed 82% similarity with Mesorhabditis paucipapillata (MT710243). The phylogenetic analysis of 28S and ITS rDNA placed the new species separately from the other Mesorhabditis. Description, measurements, illustrations and SEM micrographs for M. sudafricana n. sp. are provided.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48365089","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 : 2023-06-01DOI: 10.1163/15685411-bja10259
I. Cid del Prado Vera, S. Subbotin
Two new species of the genus Meloidodera collected in Mexico are described here: M. ferrisi sp. n. parasitising roots of an oak tree in the State of Mexico and M. tecoacensis sp. n. parasitising roots of buffalo bur nightshade in the Tlaxcala State. Meloidodera ferrisi sp. n. is characterised by a spherical female body covered completely by a dark thick cuticular layer, length/width of the female body = 0.8-1.6, stylet = 35-43 μm and second-stage juvenile with average body = 340 μm and average tail length = 35.6 μm. Meloidodera tecoacensis sp. n. is characterised by the female having a spherical body covered with a yellow transparent material, length/width of the female body = 1.1-2.8, stylet = 20-33 μm and second-stage juvenile with average body = 340 μm and average tail length = 29.8 μm. These two species were molecularly characterised using the D2-D3 expansion segments of 28S rRNA, ITS rRNA and COI gene sequences. Phylogenetic analysis revealed that the two new species represent a separate evolutionary lineage within the subfamily Meloidoderinae. An identification key for 12 Meloidodera species is provided.
{"title":"Two new species of sedentary nematodes of the genus Meloidodera Chitwood, Hannon & Esser, 1956 (Tylenchida: Heteroderidae) from Mexico","authors":"I. Cid del Prado Vera, S. Subbotin","doi":"10.1163/15685411-bja10259","DOIUrl":"https://doi.org/10.1163/15685411-bja10259","url":null,"abstract":"\u0000Two new species of the genus Meloidodera collected in Mexico are described here: M. ferrisi sp. n. parasitising roots of an oak tree in the State of Mexico and M. tecoacensis sp. n. parasitising roots of buffalo bur nightshade in the Tlaxcala State. Meloidodera ferrisi sp. n. is characterised by a spherical female body covered completely by a dark thick cuticular layer, length/width of the female body = 0.8-1.6, stylet = 35-43 μm and second-stage juvenile with average body = 340 μm and average tail length = 35.6 μm. Meloidodera tecoacensis sp. n. is characterised by the female having a spherical body covered with a yellow transparent material, length/width of the female body = 1.1-2.8, stylet = 20-33 μm and second-stage juvenile with average body = 340 μm and average tail length = 29.8 μm. These two species were molecularly characterised using the D2-D3 expansion segments of 28S rRNA, ITS rRNA and COI gene sequences. Phylogenetic analysis revealed that the two new species represent a separate evolutionary lineage within the subfamily Meloidoderinae. An identification key for 12 Meloidodera species is provided.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48729219","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 : 2023-06-01DOI: 10.1163/15685411-bja10255
Giulia Godina, B. Vandenbossche, A. Centurión, Verena Dörfler, Mike Barg, R. Ehlers, C. Molina
The entomopathogenic nematode (EPN), Heterorhabditis bacteriophora, is a biocontrol agent with almost world-wide distribution, thus providing a huge source of biodiversity available for exploitation in breeding programmes to improve beneficial traits. For management of economically important insect pests, the nematode is mass-produced in liquid culture, formulated with inert carriers, and transported under controlled temperature conditions to maintain its quality. The biocontrol potential of nematode materials is defined by their genetic background. Previous reports have assessed the phenotypic plasticity of H. bacteriophora. Major beneficial traits are field efficacy influenced by their virulence, longevity and field persistence and tolerance to abiotic stresses like oxidative stress, desiccation and extreme low and high temperatures. For several of these traits high heritability values (h2) have been reported, providing a platform for trait improvement by selection. Modern breeding uses molecular markers to track beneficial traits. Recent studies reported hundreds of single nucleotide polymorphisms (SNPs) in H. bacteriophora. This investigation revived a large set of cryopreserved wild types, hybrids and phenotyped materials of H. bacteriophora. Additional phenotypic data on the virulence (LC50) of H. bacteriophora strains against mealworm (Tenebrio molitor) were produced ranging from 1.4 ± 0.3 to 8.0 ± 3.6 nematodes per insect. Markers linked to beneficial traits were used for a comprehensive genotype analysis transferring reported SNP sequence information into the multiplex platform SeqSNP. Specific alleles associated to beneficial traits were identified and 65 materials were classified for the presence of relevant SNPs associated to beneficial traits. This information provides a valuable platform for exploitation of the nematode’s biodiversity for future breeding and selection approaches.
{"title":"New genotyping rescues old phenotypes: beneficial traits in Heterorhabditis bacteriophora wild type material and association to single nucleotide polymorphisms","authors":"Giulia Godina, B. Vandenbossche, A. Centurión, Verena Dörfler, Mike Barg, R. Ehlers, C. Molina","doi":"10.1163/15685411-bja10255","DOIUrl":"https://doi.org/10.1163/15685411-bja10255","url":null,"abstract":"\u0000The entomopathogenic nematode (EPN), Heterorhabditis bacteriophora, is a biocontrol agent with almost world-wide distribution, thus providing a huge source of biodiversity available for exploitation in breeding programmes to improve beneficial traits. For management of economically important insect pests, the nematode is mass-produced in liquid culture, formulated with inert carriers, and transported under controlled temperature conditions to maintain its quality. The biocontrol potential of nematode materials is defined by their genetic background. Previous reports have assessed the phenotypic plasticity of H. bacteriophora. Major beneficial traits are field efficacy influenced by their virulence, longevity and field persistence and tolerance to abiotic stresses like oxidative stress, desiccation and extreme low and high temperatures. For several of these traits high heritability values (h2) have been reported, providing a platform for trait improvement by selection. Modern breeding uses molecular markers to track beneficial traits. Recent studies reported hundreds of single nucleotide polymorphisms (SNPs) in H. bacteriophora. This investigation revived a large set of cryopreserved wild types, hybrids and phenotyped materials of H. bacteriophora. Additional phenotypic data on the virulence (LC50) of H. bacteriophora strains against mealworm (Tenebrio molitor) were produced ranging from 1.4 ± 0.3 to 8.0 ± 3.6 nematodes per insect. Markers linked to beneficial traits were used for a comprehensive genotype analysis transferring reported SNP sequence information into the multiplex platform SeqSNP. Specific alleles associated to beneficial traits were identified and 65 materials were classified for the presence of relevant SNPs associated to beneficial traits. This information provides a valuable platform for exploitation of the nematode’s biodiversity for future breeding and selection approaches.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45186479","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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