Nematology最新文献_第3页

Xenorhabdus bakwenae sp. n., associated with the entomopathogenic nematode Steinernema bakwenae bakwenae Xenorhabdus sp. n.，与昆虫病原线虫bakwenae steinnema有关

4区生物学

Nematology Pub Date : 2023-10-18 DOI: 10.1163/15685411-bja10284

Carla L. Ritter, Antoinette P. Malan, Leon M.T. Dicks

{"title":"Xenorhabdus bakwenae sp. n., associated with the entomopathogenic nematode Steinernema bakwenae","authors":"Carla L. Ritter, Antoinette P. Malan, Leon M.T. Dicks","doi":"10.1163/15685411-bja10284","DOIUrl":"https://doi.org/10.1163/15685411-bja10284","url":null,"abstract":"Summary The bacterial strain SF857 was isolated from the entomopathogenic nematode, Steinernema bakwenae SF857, found in soil samples of St Lucie cherry, a species of cherry tree, from the Muriti farm, close to Kroondal (25°44′E, 59°99′S) in the northwest province of South Africa. Strain SF857 is Gram-negative, catalase and oxidase-negative, and lecithinase-positive. Strain SF857 shared the highest 16S rRNA gene sequence similarity (97.7%) with the type strain of Xenorhabdus ishibashii . However, a comparison of housekeeping gene sequences showed that strain SF857 grouped closer to X. griffiniae , X. ehlersii and X. thuongxuanensis than to X. ishibashii . Digital DNA-DNA hybridisation (dDDH) between strain SF857 and all Xenorhabdus spp. is less than the 70% species threshold, confirming that the strain belongs to a separate species. Furthermore, the biochemical characteristics of strain SF857 differ from other Xenorhabdus spp. Based on these findings, strain SF857 represents a novel species within the genus Xenorhabdus , for which the name Xenorhabdus bakwenae sp. n. (type strain SF857 T ) is proposed. Pathogenicity bioassays with last-instar Cydia pomonella showed S. bakwenae to be highly virulent, with potential use as a biocontrol agent in apple orchards.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":"21 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135942874","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}

引用次数: 0

Sachsia putridicola n. sp. (Rhabditida: Diplogastridae), isolated from an Onthophagus dung beetle (Coleoptera: Scarabaeidae) from Tsukuba, Japan Sachsia putridicola n. sp. (Rhabditida: Diplogastridae), isolated from an Onthophagus dung beetle (Coleoptera: Scarabaeidae) from Tsukuba, Japan

IF 1.2 4区生物学

Nematology Pub Date : 2023-10-05 DOI: 10.1163/15685411-bja10282

N. Kanzaki, Yousuke Degawa

{"title":"Sachsia putridicola n. sp. (Rhabditida: Diplogastridae), isolated from an Onthophagus dung beetle (Coleoptera: Scarabaeidae) from Tsukuba, Japan","authors":"N. Kanzaki, Yousuke Degawa","doi":"10.1163/15685411-bja10282","DOIUrl":"https://doi.org/10.1163/15685411-bja10282","url":null,"abstract":"An undescribed Sachsia species (Diplogastridae) was isolated from a dung beetle, Onthophagus sp. cf. atripennis, and the species is described here as Sachsia putridicola n. sp. The new species is characterised by its cheilostom; anterior part forming a cuticular ring, posterior part in the form of a thin-walled tube; an anisotopic gymnostom, a metastegostom with dorsal small tooth and no subventral armature, and setiform male genital papillae with the arrangement . Sachsia putridicola n. sp. is typologically similar to two previously described congeners, Sachsia zurstrasseni and Sachsia postpapillata, but can be readily distinguished by its anisotopic gymnostom (vs isotopic gymnostom in the two nominal species) and the direction of the anterior three pairs of genital papillae, which are directed sublaterally in the new species (vs second or third pair directed sublaterally in S. zurstrasseni and S. postpapillata, respectively). Phylogenetically, the new species is close to Eudiplogasterium evidentum, not S. zurstrasseni. Based on the typological and phylogenetic characters, the status of S. zurstrasseni is discussed.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":"14 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139323218","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}

引用次数: 0

Population dynamics and damage threshold of Pratylenchus n. sp. and Meloidogyne javanica on finger millet Pratylenchus n. sp. 和 Meloidogyne javanica 在黍上的种群动态和危害阈值

IF 1.2 4区生物学

Nematology Pub Date : 2023-10-05 DOI: 10.1163/15685411-bja10283

B. Waweru, Njira Njira Pili, Wim M.L. Wesemael, Cecilia Wanjau, M. G. Teklu, G. Gheysen

{"title":"Population dynamics and damage threshold of Pratylenchus n. sp. and Meloidogyne javanica on finger millet","authors":"B. Waweru, Njira Njira Pili, Wim M.L. Wesemael, Cecilia Wanjau, M. G. Teklu, G. Gheysen","doi":"10.1163/15685411-bja10283","DOIUrl":"https://doi.org/10.1163/15685411-bja10283","url":null,"abstract":"Finger millet (Eleusine coracana) is a staple crop for subsistence farmers and is primarily cultivated in arid and semi-arid regions. Nevertheless, there are limited data available on the occurrence of plant-parasitic nematodes that specifically target finger millet, and the damage arising from such infections. In this study, we investigated the population dynamics, damage threshold and tolerance of the lesion nematode, Pratylenchus n. sp., and the root-knot nematode, Meloidogyne javanica, on finger millet ‘P-224’. We used 11 initial population densities (Pi) of second-stage juveniles (J2): 0, 0.125, 0.25, 0.5, 1, 2, 4, 8, 16, 32 and 64 J2 (g soil)−1 for M. javanica and the same densities of mixed life-stages for Pratylenchus n. sp. The logistic growth model, Seinhorst yield loss and population dynamic models were fitted to the shoot height, plant biomass and final nematode population density. Based on the population dynamics model parameters, maximum multiplication rates and maximum population densities for each nematode species were estimated. The maximum multiplication rates (a) were 32.39 and 17.46, whilst the maximum population densities (M) were 18.83 nematodes (g soil)−1 and 19.78 J2 (g soil)−1 for Pratylenchus n. sp. and M. javanica respectively. The maximum height reached (C) was negatively affected by increasing Pi for both nematode genera, while the rate of growth (B) and the time to reach was not affected based on the logistic model. A tolerance limit (T) of 1.70 nematodes (g soil)−1 and 0.65 J2 (g soil)−1; relative minimum grain yield (m) of 0.23 and 0.40 for Pratylenchus n. sp. and M. javanica was found, respectively. The results indicate that ‘P-224’ is a good host for both Pratylenchus n. sp. and M. javanica, which significantly reduce yield. These findings can be used as a base to develop effective nematode management strategies for finger millet.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":"22 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139323009","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}

引用次数: 0

Identification and reproduction of dagger nematode, Xiphinema americanum, in potato 马铃薯短柄线虫的鉴定与繁殖

4区生物学

Nematology Pub Date : 2023-09-29 DOI: 10.1163/15685411-bja10281

Mankanwal Goraya, Guiping Yan, Addison Plaisance, Zafar A. Handoo

{"title":"Identification and reproduction of dagger nematode, Xiphinema americanum, in potato","authors":"Mankanwal Goraya, Guiping Yan, Addison Plaisance, Zafar A. Handoo","doi":"10.1163/15685411-bja10281","DOIUrl":"https://doi.org/10.1163/15685411-bja10281","url":null,"abstract":"Summary Plant-parasitic nematodes limit potato production by feeding on roots, reducing tuber yield and quality, and resulting in poor growth. Dagger nematodes ( Xiphinema spp.) can pose a significant threat to crop production even in low numbers. Dagger nematodes have been reported in North Dakota, USA, potato fields. In this study, a dagger nematode species was identified and its reproduction potential in 21 potato cultivars was evaluated. The dagger nematode was identified as X. americanum via morphometric measurements and DNA sequence analysis. At the molecular level, D2-D3 of 28S ribosomal RNA (rRNA) and internal transcribed spacer (ITS)-regions of rDNA were targeted. Sequencing data of D2-D3 (749 bp) showed 98.18% similarity with three isolates of X. americanum . ITS sequence (860 bp) analysis showed 97.68% similarity with an isolate of X. americanum but lower similarity with other species of Xiphinema . The phylogenetic analysis of ITS region further confirmed the species of dagger nematode as X. americanum . Using naturally infested soil, two glasshouse experiments were conducted to assess the reproduction rate of X. americanum on 21 potato cultivars belonging to four distinct market potato classes (yellow, red, white and russet). The reproduction rates were found to vary among the potato classes and cultivars. Numerically, X. americanum population density was higher in ‘Soraya’, whereas ‘Ranger Russet’, ‘Manistee’, ‘Kennebec’, ‘Russet Norkotah 278’, ‘Modoc’, ‘Pomerelle Russet’ and ‘Dakota Rose’ reduced nematode reproduction in both trials. This is the first study demonstrating the reproduction of X. americanum in potato cultivars and could be helpful to manage dagger nematodes.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135247451","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}

引用次数: 0

Revision of the genus Metoncholaimus (Nematoda: Enoplida) with description of new species from the South China Sea 文章题目线虫属的修订及南海新种描述(线虫纲:线虫纲)

4区生物学

Nematology Pub Date : 2023-09-28 DOI: 10.1163/15685411-bja10279

Julia K. Zograf, Kseniya V. Efimova, Yulia A. Trebukhova, Olga N. Pavlyuk

引用次数: 0

Deladenus taedae n. sp. (Nematoda: Neotylenchidae) in Loblolly pine (Pinus taeda) woods from USA intercepted in Ningbo, P.R. China 在中国宁波截获的美国火炬松（Pinus taeda）林中的Deladenus taedae n.sp.（线虫目：新线虫科）

IF 1.2 4区生物学

Nematology Pub Date : 2023-08-31 DOI: 10.1163/15685411-bja10280

Qing Yu, J. Gu, W. Ye

引用次数: 0

Soil nematode communities in riverbanks non-invaded and invaded by Fallopia japonica across diverse environmental conditions 不同环境条件下非入侵和入侵河岸的土壤线虫群落

IF 1.2 4区生物学

Nematology Pub Date : 2023-08-30 DOI: 10.1163/15685411-bja10277

A. Čerevková, Michaela Jakubcsiková, L. Demková, M. Renčo

{"title":"Soil nematode communities in riverbanks non-invaded and invaded by Fallopia japonica across diverse environmental conditions","authors":"A. Čerevková, Michaela Jakubcsiková, L. Demková, M. Renčo","doi":"10.1163/15685411-bja10277","DOIUrl":"https://doi.org/10.1163/15685411-bja10277","url":null,"abstract":"\u0000Soil nematode communities are one of the most used bioindicators for assessing soil health and soil conditions. However, they are dependent on the presence of plants, some of which, known as ‘invasive’, affect local biodiversity when established. This study aimed to compare the communities of soil nematodes in riverbanks non-invaded and invaded by Fallopia japonica at three sites characterised by different environmental conditions. Our findings indicated that the ecosystem had a larger impact on the nematode communities than did the environmental variability at the study sites. Soil properties, such as pH, moisture content and organic-carbon content, differed significantly amongst the sites, but the nematode communities remained similar. Organic-carbon content was lower, and soil pH was higher, in the ecosystem with invasive F. japonica. Total nematode abundance, the abundances of fungivores, herbivores, omnivores and predators, and the maturity indices were significantly lower with invasive F. japonica. Fungivorous nematodes are essential for breaking down organic matter and releasing nutrients. Herbivorous nematodes respond to changes in the vegetation, and omnivorous and predatory nematodes contribute to the overall biodiversity and ecological balance in the soil ecosystem, so their lower abundance suggests a disturbance in the soil food web. The lower maturity indices suggested a disturbance or degradation of the soil ecosystem, which could have secondary negative effects on plant growth, nutrient availability and ecosystem resilience. These findings indicate that invasion both decreased the abundance of important soil organisms and disrupted the cycling of nutrients, potentially leading to long-term negative consequences for the invaded ecosystems. Understanding and managing the effects of invasive plants such as F. japonica are crucial for preserving soil health and promoting sustainable ecosystem functioning.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41810496","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}

引用次数: 0

New pattern of nematode spermatogenesis revealed by ultrastructural observation of Anaplectus granulosus (Plectidae, Plectida) 颗粒无刺线虫超微结构观察揭示线虫精子发生的新模式（Plectidae，Plectida）

IF 1.2 4区生物学

Nematology Pub Date : 2023-08-25 DOI: 10.1163/15685411-bja10275

V. V. Yushin, M. Claeys, W. Bert

{"title":"New pattern of nematode spermatogenesis revealed by ultrastructural observation of Anaplectus granulosus (Plectidae, Plectida)","authors":"V. V. Yushin, M. Claeys, W. Bert","doi":"10.1163/15685411-bja10275","DOIUrl":"https://doi.org/10.1163/15685411-bja10275","url":null,"abstract":"\u0000This paper presents the first comprehensive detailed transmission electron microscope observations of sperm development and structure of a plectid nematode. Sperm development of Anaplectus granulosus resembles that of nematodes of the order Rhabditida, known as the rhabditid pattern of spermatogenesis. It includes formation of complexes of fibrous bodies (FB) with membranous organelles (MO), which appear in spermatocytes; the complexes dissociate in the spermatids. The mature spermatozoa are bipolar cells subdivided into a pseudopod and a main cell body containing a nucleus with nine singlet centrioles, peripheral mitochondria and MOs. However, the development and structure of sperm in A. granulosus deviates remarkably from the common rhabditid pattern by an unusual early transformation of FBs into large amorphous masses in the spermatids; the subsequent formation of a concentric structure of immature spermatozoa with a predominant amorphous mass around the central nucleus and thin peripheral cytoplasm with organelles (MOs and mitochondria); and by the transformation of MO in mature spermatozoa into simple cisterns. Thus, the pattern of spermatogenesis of A. granulosus supports the close relations of Plectida and Rhabditida, but specific peculiarities of the sperm development delineate Plectida from Rhabditida and other orders.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43158670","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}

引用次数: 0

Ecto- and endo-parasitism of Ditylenchus destructor on garlic roots 大蒜根上双烯虫的外寄生和内寄生

IF 1.2 4区生物学

Nematology Pub Date : 2023-08-25 DOI: 10.1163/15685411-bja10276

Kazuki Tadamura, Dai Mori, A. Torada, T. Yoshiga

引用次数: 0

Dynamics of Aphelenchoides besseyi in different rice cultivars 不同水稻品种贝氏蚜的动态

IF 1.2 4区生物学

Nematology Pub Date : 2023-08-21 DOI: 10.1163/15685411-bja10274

Fang Yang, Jialian Xie, Mei Zhang, Hanlin Wu, Yun-liang Peng, H. Ji

{"title":"Dynamics of Aphelenchoides besseyi in different rice cultivars","authors":"Fang Yang, Jialian Xie, Mei Zhang, Hanlin Wu, Yun-liang Peng, H. Ji","doi":"10.1163/15685411-bja10274","DOIUrl":"https://doi.org/10.1163/15685411-bja10274","url":null,"abstract":"\u0000Aphelenchoides besseyi is among the most devastating plant-parasitic nematodes and causes severe loss, mainly on japonica rice in China. Recently the nematode has been found to be present in the seeds of indica rice and the hybrid rice cultivars also show symptoms of the nematode damage. To understand the variations in different rice cultivars against A. besseyi, the dynamics of nematode population, the incidence of symptoms and the effects on plant yield were investigated in field experiments during 2017-2018 by inoculation of mixed stages of A. besseyi onto the seeds and seedlings of different types of rice cultivars. The results showed few nematodes could be recovered from the plants at the seedling and the end of tillering stages in all the cultivars. After flowering, the number of nematodes per panicle increased and the highest number was found in ‘Zheyou 18’ in 2017 (1050.2) and 2018 (732.1). The average incidence of the inoculated plants showing white-tip symptoms ranged from 0.5 to 10.3% and from 0.0 to 75.7% at the tillering stage in 2017 and 2018, respectively. The incidences of white-tip symptoms in the indica cultivars, including ‘9311’, ‘Minghui 63’ and ‘Nei 5 you 39’, were significantly lower than in ‘Xingxiang’, a japonica cultivar and ‘Zheyou 18’, a hybrid rice cultivar, both at the flowering stage in 2017 and at the end of the tillering stage in 2018. A strong interaction of the treatments and cultivars on the 1000-grain weight and panicle length was evident.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":"1 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64643753","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}

引用次数: 0