Pub Date : 2023-03-08DOI: 10.1163/15685411-bja10230
J. Gu, Xinxin Ma
Bark in an empty container from the USA was inspected in Ningbo port, China, and a Devibursaphelenchus population was detected. It was processed and identified as Devibursaphelenchus minor sp. n. The new species is characterised by the lateral field with three incisures, female stylet tripartite, 13.9 (12.7-14.6) μm long without basal thickenings, secretory-excretory pore at the same level as nerve ring or slightly posterior, vagina not sclerotised, vulval lips slightly protruding and vulval flap absent. Post-vulval uterine sac (PUS) not well developed, very short and obscure, extending for half vulval body diam. long, anus and rectum indistinct or absent. Posterior body region conical elongated, gradually narrowing, slightly ventrally curved, ending with a bluntly pointed terminus. Male rare, the spicules are arcuate, separate, 8.2 μm along the chord line, with well-developed condylus, triangular rostrum with finely rounded tip, cucullus or apophysis absent. Tail conical, dorsally convex, ventrally slightly concave with bluntly pointed terminus, ventral bursa not confirmed. Two pairs of genital papillae present. It differs from all other species in this genus by extremely short body length of females and males. Molecular phylogenetic analyses based upon rRNA D2-D3 sequences confirmed it as a new species.
在中国宁波港对一个来自美国的空集装箱中的树皮进行了检查，并检测到了一个Devibursphelenchus种群。经加工鉴定为Devibursphelenchus minor sp.n。该新种的特征是侧野有三个切口，雌管心针三方，长13.9（12.7-14.6）μm，无基底增厚，分泌排泄孔与神经环水平或稍靠后，阴道未硬化，外阴唇稍突出，外阴瓣缺失。外阴后子宫囊（PUS）发育不全，非常短且不明显，延伸至外阴体直径的一半长，肛门和直肠模糊或缺失。身体后部区域圆锥形拉长，逐渐变窄，腹侧稍弯曲，末端有钝尖的末端。雄性罕见，骨针呈弓形，分离，沿弦线8.2μm，髁状突发育良好，三角形主席台顶端细圆形，无葫芦或隆起。尾圆锥形，背凸，腹面稍凹具钝尖的末端，腹面囊未确认。存在两对生殖乳头。它与本属所有其他物种的不同之处在于，雌性和雄性的体长都非常短。基于rRNA D2-D3序列的分子系统发育分析证实它是一个新物种。
{"title":"Detection and identification of Devibursaphelenchus minor sp. n. isolated in the bark from the USA","authors":"J. Gu, Xinxin Ma","doi":"10.1163/15685411-bja10230","DOIUrl":"https://doi.org/10.1163/15685411-bja10230","url":null,"abstract":"\u0000Bark in an empty container from the USA was inspected in Ningbo port, China, and a Devibursaphelenchus population was detected. It was processed and identified as Devibursaphelenchus minor sp. n. The new species is characterised by the lateral field with three incisures, female stylet tripartite, 13.9 (12.7-14.6) μm long without basal thickenings, secretory-excretory pore at the same level as nerve ring or slightly posterior, vagina not sclerotised, vulval lips slightly protruding and vulval flap absent. Post-vulval uterine sac (PUS) not well developed, very short and obscure, extending for half vulval body diam. long, anus and rectum indistinct or absent. Posterior body region conical elongated, gradually narrowing, slightly ventrally curved, ending with a bluntly pointed terminus. Male rare, the spicules are arcuate, separate, 8.2 μm along the chord line, with well-developed condylus, triangular rostrum with finely rounded tip, cucullus or apophysis absent. Tail conical, dorsally convex, ventrally slightly concave with bluntly pointed terminus, ventral bursa not confirmed. Two pairs of genital papillae present. It differs from all other species in this genus by extremely short body length of females and males. Molecular phylogenetic analyses based upon rRNA D2-D3 sequences confirmed it as a new species.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45712282","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 : 2023-03-08DOI: 10.1163/15685411-bja10232
H. Wileman, R. Perry, K. Davies
Plant-parasitic nematodes (PPN) are an economically important group of crop pests and are oviparous animals; all nutrients required to develop and ensure the survival of their unhatched progeny need to be deposited within the egg, including proteins. The most abundant protein deposited is vitellin, formed of a precursor protein vitellogenin, which has roles in transporting lipids, providing amino acids and influencing post-embryonic development. The genes encoding vitellogenin have been well studied in Caenorhabditis elegans, but little is known about vitellogenin in PPN. Using the vitellogenin gene sequences from C. elegans, homologous sequences in the genomes of some economically important cyst and root-knot nematodes were identified and hypothetical vitellogenin genes were predicted. Protein domains were then determined. Sequences were aligned using MUSCLE and then used to construct phylogenetic trees using the maximum likelihood method. With the availability of genomic data and use of online local alignment tools, the vitellogenin encoding genes from C. elegans could be aligned to PPN genomes. All predicted genes contained the same protein domains as C. elegans; Vitellogenin_N, vitellogenin open beta-sheet and von Willebrand factor domain type D. The constructed phylogenetic tree clustered the species into four groups: root-knot nematodes, two cyst nematode groups and Caenorhabditis species. By determining the hypothetical vitellogenin genes in PPN and inferring their relationships, this could form a potential basis to understand further the role of vitellogenin in cyst and root-knot nematodes.
{"title":"Comparative phylogenetic analysis of vitellogenin in species of cyst and root-knot nematodes","authors":"H. Wileman, R. Perry, K. Davies","doi":"10.1163/15685411-bja10232","DOIUrl":"https://doi.org/10.1163/15685411-bja10232","url":null,"abstract":"\u0000Plant-parasitic nematodes (PPN) are an economically important group of crop pests and are oviparous animals; all nutrients required to develop and ensure the survival of their unhatched progeny need to be deposited within the egg, including proteins. The most abundant protein deposited is vitellin, formed of a precursor protein vitellogenin, which has roles in transporting lipids, providing amino acids and influencing post-embryonic development. The genes encoding vitellogenin have been well studied in Caenorhabditis elegans, but little is known about vitellogenin in PPN. Using the vitellogenin gene sequences from C. elegans, homologous sequences in the genomes of some economically important cyst and root-knot nematodes were identified and hypothetical vitellogenin genes were predicted. Protein domains were then determined. Sequences were aligned using MUSCLE and then used to construct phylogenetic trees using the maximum likelihood method. With the availability of genomic data and use of online local alignment tools, the vitellogenin encoding genes from C. elegans could be aligned to PPN genomes. All predicted genes contained the same protein domains as C. elegans; Vitellogenin_N, vitellogenin open beta-sheet and von Willebrand factor domain type D. The constructed phylogenetic tree clustered the species into four groups: root-knot nematodes, two cyst nematode groups and Caenorhabditis species. By determining the hypothetical vitellogenin genes in PPN and inferring their relationships, this could form a potential basis to understand further the role of vitellogenin in cyst and root-knot nematodes.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49522924","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 : 2023-03-08DOI: 10.1163/15685411-bja10231
A. Ryss, A. Petrov
The sex organs are important for nematode systematics, but the associated muscles are rarely used as phylogenetic characters. This research aimed to study the musculature of Panagrolaimus detritophagus, using confocal microscopy. The ring-shaped anal sphincter is pierced by a biconical X-structure and connected by two pairs of processes to the subventral stomato-intestinal muscles and dorsal body wall. The female has two pairs of vaginal dilators that are connected to the proximally invaginated vaginal sphincter and subventral body wall. The anal depressor is a pair of dorsoventral muscles. The male has 7-8 pairs of caudal diagonal muscles located beneath the ventral body wall muscles, followed by five pairs of postcloacal oblique muscles. The paired posterior longitudinal muscles are connected to the cloacal opening and tail tip. The paired anterior retractors of the spicule connect the spicule capitula to the lateral body wall; a pair of spicule-gubernacular protractors runs from spicule capitula to the anterior part of gubernaculum, and paired ventral protractors run from spicule capitula to anterior cloacal lip. Two pairs of gubernaculum erectors are attached to the mid-gubernaculum, and the unpaired gubernaculum protractor extends ventrally to attach to the body wall at the posterior cloacal lip. The sex muscle pattern is of the Rhabditidae-Cephalobidae type with a 15-character code for phylogenetic reconstructions: 63313-22234-42243.
{"title":"Muscles of the sex organs of Panagrolaimus detritophagus (Chromodorea: Rhabditida: Panagrolaimidae)","authors":"A. Ryss, A. Petrov","doi":"10.1163/15685411-bja10231","DOIUrl":"https://doi.org/10.1163/15685411-bja10231","url":null,"abstract":"\u0000The sex organs are important for nematode systematics, but the associated muscles are rarely used as phylogenetic characters. This research aimed to study the musculature of Panagrolaimus detritophagus, using confocal microscopy. The ring-shaped anal sphincter is pierced by a biconical X-structure and connected by two pairs of processes to the subventral stomato-intestinal muscles and dorsal body wall. The female has two pairs of vaginal dilators that are connected to the proximally invaginated vaginal sphincter and subventral body wall. The anal depressor is a pair of dorsoventral muscles. The male has 7-8 pairs of caudal diagonal muscles located beneath the ventral body wall muscles, followed by five pairs of postcloacal oblique muscles. The paired posterior longitudinal muscles are connected to the cloacal opening and tail tip. The paired anterior retractors of the spicule connect the spicule capitula to the lateral body wall; a pair of spicule-gubernacular protractors runs from spicule capitula to the anterior part of gubernaculum, and paired ventral protractors run from spicule capitula to anterior cloacal lip. Two pairs of gubernaculum erectors are attached to the mid-gubernaculum, and the unpaired gubernaculum protractor extends ventrally to attach to the body wall at the posterior cloacal lip. The sex muscle pattern is of the Rhabditidae-Cephalobidae type with a 15-character code for phylogenetic reconstructions: 63313-22234-42243.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45180210","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 : 2023-03-08DOI: 10.1163/15685411-bja10234
J. Gu, Xinxin Ma, P. Castillo, M. Munawar
The study aims to provide the morphological and molecular characterisation of two newly discovered Cryptaphelenchus species, namely: C. curvatum n. sp. and C. tumidus n. sp. Morphologically both species are minute nematodes, possess medium-sized stylets with basal knobs laterally directed, and short post-uterine sacs (PUS). Cryptaphelenchus curvatum n. sp. was detected from the local Pinus branch samples and is characterised by having an equal proportion of adult males and females, medium-sized body lengths of females 353 (320-388) μm and males 277 (256-293) μm, lateral fields with four lateral lines, 8-10 μm long stylet, PUS about one vulva body width long and conical posterior body end with a blunt pointed tip. Cryptaphelenchus tumidus n. sp. was detected in a packaging wood sample from Japan and is characterised by having rare male, short body lengths of females 236 (217-270) μm and males 180 μm, obscure lateral fields, stylet 6.8 (6.0-7.5) μm, PUS about half vulva body width long and a slim conical posterior body end with a finely rounded tip. The phylogenetic trees were also constructed based on rRNA gene sequences (D2-D3 segments of the 28S, ITS and 18S) and discussed in detail. Since Cryptaphelenchus species offer multitrophic relationships among their insect vectors and associated microbiota, species recognition and molecular studies of recovered populations will facilitate researchers to determine whether these species might play any ecological roles in insect bionomics or the residing host tree.
本研究旨在提供两种新发现的隐线虫种C. curvatum n. sp和C. tumidus n. sp的形态和分子特征。这两种线虫在形态上都是微小的线虫，具有中等大小的柱头，基部柄向侧面，子宫后囊(PUS)短。摘要在当地松枝样本中检测到弯隐叶松(Cryptaphelenchus curvatum n. spp)，雌雄比例相等，体长中等，雌体353 (320 ~ 388)μm，雄体277 (256 ~ 293)μm，侧野有4条侧线，花柱长8 ~ 10 μm，阴唇长约1外阴体宽，体后端呈圆锥形，尖端钝尖。在日本的包装木材样品中检测到隐helenchus tumidus n. spp，其特征是雄性罕见，体长短，雌性为236 (217-270)μm，雄性为180 μm，侧野模糊，花柱6.8 (6.0-7.5)μm，外阴体宽约一半长，体后端呈细长圆锥形，顶端呈精细圆形。基于rRNA基因序列(28S、ITS和18S的D2-D3段)构建了系统发育树，并进行了详细的讨论。由于隐螺旋藻物种在其昆虫媒介和相关微生物群之间具有多营养关系，因此对恢复种群的物种识别和分子研究将有助于研究人员确定这些物种是否在昆虫生物学或居住寄主树中发挥任何生态作用。
{"title":"Description of two new Cryptaphelenchus species from China and Japan","authors":"J. Gu, Xinxin Ma, P. Castillo, M. Munawar","doi":"10.1163/15685411-bja10234","DOIUrl":"https://doi.org/10.1163/15685411-bja10234","url":null,"abstract":"\u0000The study aims to provide the morphological and molecular characterisation of two newly discovered Cryptaphelenchus species, namely: C. curvatum n. sp. and C. tumidus n. sp. Morphologically both species are minute nematodes, possess medium-sized stylets with basal knobs laterally directed, and short post-uterine sacs (PUS). Cryptaphelenchus curvatum n. sp. was detected from the local Pinus branch samples and is characterised by having an equal proportion of adult males and females, medium-sized body lengths of females 353 (320-388) μm and males 277 (256-293) μm, lateral fields with four lateral lines, 8-10 μm long stylet, PUS about one vulva body width long and conical posterior body end with a blunt pointed tip. Cryptaphelenchus tumidus n. sp. was detected in a packaging wood sample from Japan and is characterised by having rare male, short body lengths of females 236 (217-270) μm and males 180 μm, obscure lateral fields, stylet 6.8 (6.0-7.5) μm, PUS about half vulva body width long and a slim conical posterior body end with a finely rounded tip. The phylogenetic trees were also constructed based on rRNA gene sequences (D2-D3 segments of the 28S, ITS and 18S) and discussed in detail. Since Cryptaphelenchus species offer multitrophic relationships among their insect vectors and associated microbiota, species recognition and molecular studies of recovered populations will facilitate researchers to determine whether these species might play any ecological roles in insect bionomics or the residing host tree.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45479367","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 : 2023-03-02DOI: 10.1163/15685411-bja10229
James Kisaakye, H. Fourie, D. Coyne, L. Cortada, F. Khamis, S. Subramanian, Shirlyne Masinde, S. Haukeland
The root-burrowing nematode, Radopholus similis, is reputedly the most damaging nematode pest of banana and responsible for major production losses. In this study, the endophytic potential of 13 fungal isolates was assessed for the management of R. similis in East African Highland bananas (‘Ng’ombe’). All isolates successfully colonised tissue-cultured banana roots, with isolates from Trichoderma, Fusarium and Hypocrea producing the highest (⩾49.1%) and Beauveria isolates the lowest (⩽14.4%) colonisation. The fungal endophytes T. asperellum (ICIPE 700) and H. lixii (ICIPE 697) were the most effective in reducing R. similis densities (>81%) relative to the non-inoculated control. However, the combined inoculation of ICIPE 700 and ICIPE 697 led to greater suppression of R. similis (>21%) relative to individual inoculation. Suppression of R. similis following inoculation of banana roots with ICIPE 700 and/or ICIPE 697 was associated with the significant upregulation of the defence-related gene PR-1, the cell signalling gene calmodulin Ca2+ and the cell-wall-strengthening gene β-1,3-glucan synthase. This study demonstrates the potential for nematode management in bananas with fungal endophytes, especially using the isolates ICIPE 700 and ICIPE 697 when combined.
{"title":"Endophytic fungi improve management of the burrowing nematode in banana (Musa spp.) through enhanced expression of defence-related genes","authors":"James Kisaakye, H. Fourie, D. Coyne, L. Cortada, F. Khamis, S. Subramanian, Shirlyne Masinde, S. Haukeland","doi":"10.1163/15685411-bja10229","DOIUrl":"https://doi.org/10.1163/15685411-bja10229","url":null,"abstract":"\u0000The root-burrowing nematode, Radopholus similis, is reputedly the most damaging nematode pest of banana and responsible for major production losses. In this study, the endophytic potential of 13 fungal isolates was assessed for the management of R. similis in East African Highland bananas (‘Ng’ombe’). All isolates successfully colonised tissue-cultured banana roots, with isolates from Trichoderma, Fusarium and Hypocrea producing the highest (⩾49.1%) and Beauveria isolates the lowest (⩽14.4%) colonisation. The fungal endophytes T. asperellum (ICIPE 700) and H. lixii (ICIPE 697) were the most effective in reducing R. similis densities (>81%) relative to the non-inoculated control. However, the combined inoculation of ICIPE 700 and ICIPE 697 led to greater suppression of R. similis (>21%) relative to individual inoculation. Suppression of R. similis following inoculation of banana roots with ICIPE 700 and/or ICIPE 697 was associated with the significant upregulation of the defence-related gene PR-1, the cell signalling gene calmodulin Ca2+ and the cell-wall-strengthening gene β-1,3-glucan synthase. This study demonstrates the potential for nematode management in bananas with fungal endophytes, especially using the isolates ICIPE 700 and ICIPE 697 when combined.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47310588","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 : 2023-02-24DOI: 10.1163/15685411-00003596
Josiah Marquez, A. Hajihassani, Richard F. Davis
{"title":"Corrigendum to: Evaluation of summer and winter cover crops for variations in host suitability for Meloidogyne incognita, M. arenaria and M. javanica, Nematology 24 (2022) 841-854 (DOI: 10.1163/15685411-bja10172)","authors":"Josiah Marquez, A. Hajihassani, Richard F. Davis","doi":"10.1163/15685411-00003596","DOIUrl":"https://doi.org/10.1163/15685411-00003596","url":null,"abstract":"","PeriodicalId":18928,"journal":{"name":"Nematology","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43567867","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 : 2023-02-23DOI: 10.1163/15685411-bja10227
J. Abolafia, M. Robles, A. N. Ruiz-Cuenca, E. Shokoohi
Stegelletina salinaria is redescribed from Spain and South Africa. Spanish material was collected in sandy soil from the type locality and a nearby area, while one population collected in compost was examined from South Africa. The species is characterised by its small size (0.27-0.41 mm), lateral field with three incisures, lip region with three pairs of dentate lips bearing four tines each, primary axils bearing a large guarding process, secondary axils lacking guarding processes, nerve ring and secretory-excretory pore at isthmus level, spermatheca and post-vulval uterine sac poorly developed, female tail conoid with rounded hyaline terminus and males unknown. The description, light micrographs and scanning electron microscope images, illustrations and molecular analyses are provided. 18S and 28S rDNA sequence analyses show that the isolates of S. salinaria from Spain and South Africa are closely related to each other and to other species of Stegelletina, while also indicating a close relationship with some species of Nothacrobeles, Scottnema and Stegelleta (28S tree) and Zeldia (18S tree).
{"title":"Characterisation of Stegelletina salinaria Abolafia & Peña-Santiago, 2003 (Rhabditida, Cephalobidae) from Spain and South Africa including the first molecular study of the species","authors":"J. Abolafia, M. Robles, A. N. Ruiz-Cuenca, E. Shokoohi","doi":"10.1163/15685411-bja10227","DOIUrl":"https://doi.org/10.1163/15685411-bja10227","url":null,"abstract":"Stegelletina salinaria is redescribed from Spain and South Africa. Spanish material was collected in sandy soil from the type locality and a nearby area, while one population collected in compost was examined from South Africa. The species is characterised by its small size (0.27-0.41 mm), lateral field with three incisures, lip region with three pairs of dentate lips bearing four tines each, primary axils bearing a large guarding process, secondary axils lacking guarding processes, nerve ring and secretory-excretory pore at isthmus level, spermatheca and post-vulval uterine sac poorly developed, female tail conoid with rounded hyaline terminus and males unknown. The description, light micrographs and scanning electron microscope images, illustrations and molecular analyses are provided. 18S and 28S rDNA sequence analyses show that the isolates of S. salinaria from Spain and South Africa are closely related to each other and to other species of Stegelletina, while also indicating a close relationship with some species of Nothacrobeles, Scottnema and Stegelleta (28S tree) and Zeldia (18S tree).","PeriodicalId":18928,"journal":{"name":"Nematology","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43538639","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 : 2023-02-22DOI: 10.1163/15685411-bja10228
Itaru Sakata, A. Kushida, K. Toyota
Globodera pallida is a major pest of potatoes worldwide. In Japan, aiming at eradication of G. pallida, control measures have been implemented in infested fields. To determine the necessity of control measures, the detection of viable G. pallida is required. However, the conventional inoculation test performed in Japan, named the ‘cup test,’ is time-consuming, and conventional PCR methods targeting DNA can detect dead individuals. In this study, we developed an intercalator-based RT-qPCR method for the rapid detection of viable G. pallida. We designed a primer set for the partial cDNA sequence of the Y45F10D.4 gene of G. pallida. This primer set successfully amplified Y45F10D.4 mRNA of all tested G. pallida populations without any cross-reactions with other species. The RT-qPCR method detected RNA corresponding to a minimum of 3.9 G. pallida eggs, and a significant negative correlation was observed between the concentrations of RNA extracted from viable eggs and the Ct values. In addition, no amplification by RT-qPCR was observed in G. pallida treated with 1,3-Dichloropropene, indicating that this method detected viable G. pallida specifically. We then compared the detection sensitivity between the cup test and RT-qPCR method using 24 soil samples, and the results showed that the detection sensitivity of the RT-qPCR method was higher than that of the cup test. The RT-qPCR method enabled the rapid and reliable detection of viable G. pallida.
{"title":"Species-specific detection of viable Globodera pallida using real-time reverse transcription PCR","authors":"Itaru Sakata, A. Kushida, K. Toyota","doi":"10.1163/15685411-bja10228","DOIUrl":"https://doi.org/10.1163/15685411-bja10228","url":null,"abstract":"\u0000Globodera pallida is a major pest of potatoes worldwide. In Japan, aiming at eradication of G. pallida, control measures have been implemented in infested fields. To determine the necessity of control measures, the detection of viable G. pallida is required. However, the conventional inoculation test performed in Japan, named the ‘cup test,’ is time-consuming, and conventional PCR methods targeting DNA can detect dead individuals. In this study, we developed an intercalator-based RT-qPCR method for the rapid detection of viable G. pallida. We designed a primer set for the partial cDNA sequence of the Y45F10D.4 gene of G. pallida. This primer set successfully amplified Y45F10D.4 mRNA of all tested G. pallida populations without any cross-reactions with other species. The RT-qPCR method detected RNA corresponding to a minimum of 3.9 G. pallida eggs, and a significant negative correlation was observed between the concentrations of RNA extracted from viable eggs and the Ct values. In addition, no amplification by RT-qPCR was observed in G. pallida treated with 1,3-Dichloropropene, indicating that this method detected viable G. pallida specifically. We then compared the detection sensitivity between the cup test and RT-qPCR method using 24 soil samples, and the results showed that the detection sensitivity of the RT-qPCR method was higher than that of the cup test. The RT-qPCR method enabled the rapid and reliable detection of viable G. pallida.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44396779","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}
Ditylenchus rafiqi n. sp. was recovered from the rhizosphere of pomegranate in New Delhi (India), and it is characterised by morphological, morphometrical and molecular methods. The new species is characterised by having a body length of 553-901 μm, delicate stylet (7-10 μm long), longer conus length (5.0-5.5 μm in females and 4.5-5.5 μm in males) with small round knobs sloping backward, seven lateral lines at the mid-body, median bulb well developed with thickening of lumen walls, a post-uterine sac well developed (27-47 μm), tail long, elongate conoid with an almost round terminus (45-74 μm) and male spicule of 15-17.5 μm, gubernaculum simple, leptoderan type of bursa enveloping the tail almost >50% of its tail length. A detailed study based on morphological and morphometrical methods clearly demarcates that D. rafiqi n. sp. differs from other known species of Ditylenchus. The molecular characterisation was done using D2-D3 of 28S rRNA and ITS rRNA markers. Molecular characterisation shows that the new species is closely related to D. acutus, D. gilanicus (D2-D3 marker), and D. medicaginis (ITS rRNA markers). Based on phylogenetic analyses using D2-D3 of LSU and ITS rRNA markers, D. rafiqi n. sp. forms an intermediate clade between the D. triformis and D. dipsaci groups.
{"title":"Ditylenchus rafiqi n. sp. from pomegranate (Punica granatum L.) from India with a tabular key for the species known from India","authors":"G. Vyshali, Vishal Singh Somvanshi, Md Niraul Islam, Artha Kundu, Matiyar Rahaman Khan","doi":"10.1163/15685411-bja10226","DOIUrl":"https://doi.org/10.1163/15685411-bja10226","url":null,"abstract":"\u0000Ditylenchus rafiqi n. sp. was recovered from the rhizosphere of pomegranate in New Delhi (India), and it is characterised by morphological, morphometrical and molecular methods. The new species is characterised by having a body length of 553-901 μm, delicate stylet (7-10 μm long), longer conus length (5.0-5.5 μm in females and 4.5-5.5 μm in males) with small round knobs sloping backward, seven lateral lines at the mid-body, median bulb well developed with thickening of lumen walls, a post-uterine sac well developed (27-47 μm), tail long, elongate conoid with an almost round terminus (45-74 μm) and male spicule of 15-17.5 μm, gubernaculum simple, leptoderan type of bursa enveloping the tail almost >50% of its tail length. A detailed study based on morphological and morphometrical methods clearly demarcates that D. rafiqi n. sp. differs from other known species of Ditylenchus. The molecular characterisation was done using D2-D3 of 28S rRNA and ITS rRNA markers. Molecular characterisation shows that the new species is closely related to D. acutus, D. gilanicus (D2-D3 marker), and D. medicaginis (ITS rRNA markers). Based on phylogenetic analyses using D2-D3 of LSU and ITS rRNA markers, D. rafiqi n. sp. forms an intermediate clade between the D. triformis and D. dipsaci groups.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42874229","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 : 2023-02-08DOI: 10.1163/15685411-bja10223
Koshi Gunjima, K. Toyota, Aoto Fujikawa
For a screening test to discover nematicide candidates to control Meloidogyne incognita, a potted plant-based assay to observe gall formation on the root is realistic because it can cover the nematode life-cycle period and a broad range of mode of actions of tested compounds. However, both time and labour are needed for its operation. The objective of this study was to develop a plant-based screening method enabling easy periodical observation of the progress of root gall formation under almost no soil adsorption conditions of tested compounds. As an alternative material for soil, rockwool substrate for growing vegetable seedlings was used with a nutrient solution. Observation of gall formation on the same substrates was possible for 3-4 weeks. With this method, standard nematicides, e.g., fosthiazate and fluopyram, provided clear inhibitory effect on gall formation. Their ED50 values at 21 days after inoculation of 300 second-stage juveniles (substrate)−1 were 0.0034 mg (substrate)−1 and 0.0035 mg (substrate)−1, respectively. Furthermore, conventional fungicides and insecticides were screened with the method. Activities were observed in some products like polyoxins, which showed 100% control at 25 mg (substrate)−1, a considerably higher dose than that in standard nematicides. This study developed a simple test method for evaluating inhibitory effect on gall formation by M. incognita and proved its usefulness by applying it to nematicide screening.
{"title":"Development of a simple test method for inhibitory effect of gall formation on Meloidogyne incognita and its application to nematicide screening","authors":"Koshi Gunjima, K. Toyota, Aoto Fujikawa","doi":"10.1163/15685411-bja10223","DOIUrl":"https://doi.org/10.1163/15685411-bja10223","url":null,"abstract":"\u0000For a screening test to discover nematicide candidates to control Meloidogyne incognita, a potted plant-based assay to observe gall formation on the root is realistic because it can cover the nematode life-cycle period and a broad range of mode of actions of tested compounds. However, both time and labour are needed for its operation. The objective of this study was to develop a plant-based screening method enabling easy periodical observation of the progress of root gall formation under almost no soil adsorption conditions of tested compounds. As an alternative material for soil, rockwool substrate for growing vegetable seedlings was used with a nutrient solution. Observation of gall formation on the same substrates was possible for 3-4 weeks. With this method, standard nematicides, e.g., fosthiazate and fluopyram, provided clear inhibitory effect on gall formation. Their ED50 values at 21 days after inoculation of 300 second-stage juveniles (substrate)−1 were 0.0034 mg (substrate)−1 and 0.0035 mg (substrate)−1, respectively. Furthermore, conventional fungicides and insecticides were screened with the method. Activities were observed in some products like polyoxins, which showed 100% control at 25 mg (substrate)−1, a considerably higher dose than that in standard nematicides. This study developed a simple test method for evaluating inhibitory effect on gall formation by M. incognita and proved its usefulness by applying it to nematicide screening.","PeriodicalId":18928,"journal":{"name":"Nematology","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43660731","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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