Nematology最新文献

{"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":" ","pages":""},"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}

{"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":"54 3-4","pages":""},"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}

{"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":" ","pages":""},"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}

{"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":" ","pages":""},"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}

{"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":" ","pages":""},"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}

{"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":" ","pages":""},"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}

{"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":" ","pages":""},"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}

{"title":"Steinernema indicum n. sp., a new entomopathogenic nematode (Nematoda: Steinernematidae) from India","authors":"Jagadeesh Patil, V. Linga, P. Mhatre, M. Gowda, V. Rangasamy, V. Půža","doi":"10.1163/15685411-bja10258","DOIUrl":"https://doi.org/10.1163/15685411-bja10258","url":null,"abstract":"\u0000A new species of entomopathogenic nematode, Steinernema indicum n. sp., was isolated from a coconut palm (Cocos nucifera) field in the district of Udupi, Karnataka, India. The infective juveniles (IJ) of S. indicum n. sp. possess a body length of 1043 (869-1172) μm. The lateral fields are formed by eight equally spaced and developed ridges (nine incisures) in the mid-body region, giving the formula 3, 8, 7, 5. The excretory pore is located posterior to the mid-pharynx region (D% = 63), and the hyaline region occupies ca half of the tail length. The first-generation males are characterised by very short spicules 66 (60-70) μm long. The male spicules are moderately curved with a sharp tip and are golden-brown in colour with the manubrium elongate and with a length to width ratio of 1.92:1. There are 11 pairs of genital papillae plus a single midventral papilla located anterior to the cloacal region. The first-generation male of S. indicum n. sp. is characterised by the presence of a single dorsal postcloacal papilla, a typical diagnostic character that has not been reported from any other steinernematid species. The first-generation male tail has a short mucron present in ca 40% of specimens examined and a second-generation male tail showing a short mucron present in ca 65% of male specimens examined. The first and second-generation females possess a slightly protruding post-anal swelling. The new species is further characterised by sequences of the internal transcribed spacer (ITS) and partial 28S regions (D2-D3) of the ribosomal DNA (rDNA). Phylogenetic analyses confirm that S. indicum n. sp. belongs to the glaseri-group and, based on both ITS and D2D3 genes, showed that S. indicum n. sp. is a member of the karii clade.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49527507","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":"Paraxonchium carmenae Peña-Santiago & Jiménez-Millán, 1986 revisited four decades later, with new insights into the phylogeny of the genus Paraxonchium Krall, 1958 (Dorylaimida)","authors":"R. Peña‐Santiago, M. García-Ruiz, G. Liébanas, J. Abolafia","doi":"10.1163/15685411-bja10257","DOIUrl":"https://doi.org/10.1163/15685411-bja10257","url":null,"abstract":"\u0000A revised characterisation of the dorylaimid nematode Paraxonchium carmenae is provided, including an updated description, SEM observations and molecular (18S-, 28S-rDNA) analyses. A total of 29 females and 16 males, collected from several mountain natural locations in eastern Andalusia, Spain, are studied. This species is very homogeneous morphologically, but displays wide variations in their morphometrics, although with high coincidence or overlapping when the ranges of different populations are compared. The morphology of the genus Paraxonchium is analysed and discussed, with emphasis on its remarkable interspecific variations. Results of molecular studies show a close relationship of P. carmenae with P. laetificans, the type species of the genus, and tentatively support its monophyly. Nevertheless, neither morphological nor molecular data clear up the uncertainties about its position in the Dorylaimina system.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45707294","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":"Ficophagus annulatae n. sp. (Nematoda: Aphelenchoididae), an associate of Ficus annulata in China","authors":"Yongsan Zeng, Dayuan Zhang, R. Giblin-Davis, J. Roberts","doi":"10.1163/15685411-bja10247","DOIUrl":"https://doi.org/10.1163/15685411-bja10247","url":null,"abstract":"\u0000A new species of the genus Ficophagus was recovered from the syconia of Ficus annulata from Xishuangbanna, Yunnan province, China. It is described herein as Ficophagus annulatae n. sp. and is characterised by possessing the combined characters of a short PUS (9-18 μm or 0.3-0.6 VBD long), an excretory pore (EP) located at the level between stylet basal knobs and metacorpus, presence of crustaformeria, amoeboid sperm, three pairs of subventral papillae on the male tail (one pair just adcloacal (P2), one pair halfway between cloacal aperture and tail terminus (P3), and one pair near tail tip (P4)), rounded male tail tip without mucron, absence of gubernaculum and bow-shaped spicule with indistinct rostrum. Ficophagus annulatae n. sp. was differentiated from other sequenced species by the partial small subunit (SSU) rRNA gene and D2-D3 expansion segments of the large subunit (LSU) rRNA gene. Phylogenetic analysis with the LSU D2-D3 expansion segment sequence suggested that F. annulatae n. sp. is clustered in the same highly supported monophyletic clade with F. benjamina, F. curtipes and F. microcarpus. It differs morphologically from these species in EP position, spicule and uterus morphology, and some morphometric characters.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43935884","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}