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M'rabet Samaali B, Loulou A, MougouHamdane A, Kallel S. Acquisition and transmission of Grapevine fanleaf virus (GFLV) by Xiphinema index and Xiphinema italiae (Longidoridae). J Helminthol 2024; 98:e26. [PMID: 38509862 DOI: 10.1017/s0022149x24000154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/22/2024]
Abstract
Grapevine fanleaf virus (GFLV) is one of the most severe virus diseases of grapevines, causing fanleaf degeneration that is transmitted by Xiphinema index. This paper aims to isolate Xiphinema species from Tunisian vineyard soil samples and assess their ability to acquire and transmit GFLV under natural and controlled conditions. Based on morphological and morphometric analyses, Tunisian dagger nematodes were identified as X. index and Xiphinema italiae. These results were confirmed with molecular identification tools using species-specific polymerase chain reaction primers. The total RNA of GFLV was extracted from specimens of Xiphinema and amplified based on real-time polymerase chain reaction using virus-specific primers. Our results showed that X. index could acquire and transmit the viral particles of GFLV. This nepovirus was not detected in X. italiae, under natural conditions; however, under controlled conditions, this nematode was able to successfully acquire and transmit the viral particles of GFLV.
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Affiliation(s)
- B M'rabet Samaali
- Université de Carthage, National Agronomic Institute of Tunisia, LR14AGR02, Laboratoire de Recherche Bioagresseur et Protection Intégrée en Agriculture, 1082Tunis mahrajène, Tunisia
| | - A Loulou
- Université de Carthage, National Agronomic Institute of Tunisia, LR14AGR02, Laboratoire de Recherche Bioagresseur et Protection Intégrée en Agriculture, 1082Tunis mahrajène, Tunisia
| | - A MougouHamdane
- Université de Carthage, National Agronomic Institute of Tunisia, LR14AGR02, Laboratoire de Recherche Bioagresseur et Protection Intégrée en Agriculture, 1082Tunis mahrajène, Tunisia
| | - S Kallel
- Université de Carthage, National Agronomic Institute of Tunisia, LR14AGR02, Laboratoire de Recherche Bioagresseur et Protection Intégrée en Agriculture, 1082Tunis mahrajène, Tunisia
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Huang D, Yan G, Gudmestad N, Ye W, Whitworth J, Frost K, Crow W, Hajihassani A. Developing a One-Step Multiplex PCR Assay for Rapid Detection of Four Stubby-Root Nematode Species, Paratrichodorus allius, P. minor, P. porosus, and Trichodorus obtusus. PLANT DISEASE 2019; 103:404-410. [PMID: 30598052 DOI: 10.1094/pdis-06-18-0983-re] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Four trichodorid species, Paratrichodorus allius, P. minor, P. porosus, and Trichodorus obtusus, were found in multiple states in the United States. Traditional diagnosis based on morphology and morphometrics is laborious and requires an experienced taxonomist. Additionally, end-point diagnosis using PCR was only available for P. allius. To increase diagnostic efficiency and reduce costs, a one-step multiplex PCR assay was developed to simultaneously identify these four species using one PCR reaction. Available sequences of 18S ribosomal DNA and internal transcribed spacer 1 (ITS1) region of these species were aligned and five primers were designed. The conserved forward primer located in the 18S region, in combination with the species-specific antisense primer in the ITS1 region, amplified a single distinctive PCR fragment for each species (421/425 bp for P. allius, 190 bp for P. minor, 513 bp for P. porosus, and 353 bp for T. obtusus). In silico analysis with 10 other trichodorid species and experimental analysis using samples with these four species, 20 other plant-parasitic and three non-plant-parasitic nematodes demonstrated high specificity with the primers designed. The multiplex PCR amplified desirable fragments using a set of artificially mixed templates containing one, two, three, or four targeted species. The reliability of multiplex PCR results was demonstrated by using nematode populations isolated from infested fields from diverse geographic regions in eight states. The multiplex PCR-based tool developed in this study for the first time provides a simple, rapid, and cost-friendly assay for accurate diagnosis of the four major trichodorid nematodes in the United States.
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Affiliation(s)
- Danqiong Huang
- North Dakota State University, Department of Plant Pathology, Fargo, ND 58102
| | - Guiping Yan
- North Dakota State University, Department of Plant Pathology, Fargo, ND 58102
| | - Neil Gudmestad
- North Dakota State University, Department of Plant Pathology, Fargo, ND 58102
| | - Weimin Ye
- North Carolina Department of Agriculture and Consumer Services, Raleigh, NC 27607
| | | | - Kenneth Frost
- Oregon State University, Hermiston Agricultural Research and Extension Center, Hermiston, OR 97838
| | - William Crow
- University of Florida, Entomology and Nematology Department, Gainesville, FL 32611
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The utility of mtDNA and rDNA for barcoding and phylogeny of plant-parasitic nematodes from Longidoridae (Nematoda, Enoplea). Sci Rep 2017; 7:10905. [PMID: 28883648 PMCID: PMC5589882 DOI: 10.1038/s41598-017-11085-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Accepted: 08/11/2017] [Indexed: 11/15/2022] Open
Abstract
The traditional identification of plant-parasitic nematode species by morphology and morphometric studies is very difficult because of high morphological variability that can lead to considerable overlap of many characteristics and their ambiguous interpretation. For this reason, it is essential to implement approaches to ensure accurate species identification. DNA barcoding aids in identification and advances species discovery. This study sought to unravel the use of the mitochondrial marker cytochrome c oxidase subunit 1 (coxI) as barcode for Longidoridae species identification, and as a phylogenetic marker. The results showed that mitochondrial and ribosomal markers could be used as barcoding markers, except for some species from the Xiphinema americanum group. The ITS1 region showed a promising role in barcoding for species identification because of the clear molecular variability among species. Some species presented important molecular variability in coxI. The analysis of the newly provided sequences and the sequences deposited in GenBank showed plausible misidentifications, and the use of voucher species and topotype specimens is a priority for this group of nematodes. The use of coxI and D2 and D3 expansion segments of the 28S rRNA gene did not clarify the phylogeny at the genus level.
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Canchignia H, Altimira F, Montes C, Sánchez E, Tapia E, Miccono M, Espinoza D, Aguirre C, Seeger M, Prieto H. Candidate nematicidal proteins in a new Pseudomonas veronii isolate identified by its antagonistic properties against Xiphinema index. J GEN APPL MICROBIOL 2016; 63:11-21. [PMID: 27989999 DOI: 10.2323/jgam.2016.07.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The nematode Xiphinema index affects grape vines and transmits important viruses associated with fanleaf degeneration. Pseudomonas spp. are an extensive bacterial group in which important biodegradation and/or biocontrol properties can occur for several strains in the group. The aim of this study was to identify new Pseudomonas isolates with antagonist activity against X. index. Forty bacterial isolates were obtained from soil and root samples from Chilean vineyards. Thirteen new fluorescent pseudomonads were found and assessed for their antagonistic capability. The nematicide Pseudomonas protegens CHA0 was used as a control. Challenges of nematode individuals in King's B semi-solid agar Petri dishes facilitated the identification of the Pseudomonas veronii isolate R4, as determined by a 16S rRNA sequence comparison. This isolate was as effective as CHA0 as an antagonist of X. index, although it had a different lethality kinetic. Milk-induced R4 cultures exhibited protease and lipase activities in cell supernatants using both gelatin/tributyrin Petri dish assays and zymograms. Three proteins with these activities were isolated and subjected to mass spectrometry. Amino acid partial sequences enabled the identification of a 49-kDa protease similar to metalloprotease AprA and two lipases of 50 kDa and 69 kDa similar to LipA and ExoU, respectively. Electron microscopy analyses of challenged nematodes revealed degraded cuticle after R4 supernatant treatment. These results represent a new and unexplored property in this species associated with the presence of secretable lipases and protease, similar to characterized enzymes present in biocontrol pseudomonads.
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Affiliation(s)
- Hayron Canchignia
- Biotechnology Doctoral Program, Universidad Técnica Federico Santa María-Pontificia Universidad Católica de Valparaíso
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Chizhov VN, Pridannikov MV, Peneva V, Subbotin SA. Morphological and molecular characterisation of the Saratov population of the European dagger nematode, Xiphinema diversicaudatum (Nematoda: Dorylaimida), with notes on phylogeography of the species. NEMATOLOGY 2014. [DOI: 10.1163/15685411-00002813] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Plesiotype specimens of the European dagger nematode, Xiphinema diversicaudatum, were collected in Saratov, Russia, and morphologically, morphometrically and molecularly characterised. PCR with specific primer was developed for rapid diagnostics of this species. Phylogenetic relationships of X. diversicaudatum with other Xiphinema species, as inferred from the analyses of the D2-D3 expansion segments of 28S rRNA, ITS rRNA and coxI mtDNA gene sequences, are also provided. The study revealed that the clade X. diversicaudatum, together with X. bakeri (North America) and X. chengi (Asia), is related to Xiphinema species from the Mediterranean region and likely originated from a common ancestor inhabiting this area. The phylogenetic reconstructions with coxI mtDNA were used to describe the pattern of present genetic diversity of X. diversicaudatum and infer its biogeographical history in Europe. Haplotype diversity of X. diversicaudatum populations from Central Europe was significantly higher than those from south-eastern Europe, central, south-eastern and southern European Russia. It has been hypothesised that, during the Last Glacial Maximum, X. diversicaudatum populations probably persisted in refuge areas in the Carpathian mountains or the Alps, the species subsequently expanding from these areas and colonising other regions in Europe.
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Affiliation(s)
- Vladimir N. Chizhov
- Center of Parasitology of A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences, Leninskii Prospect 33, Moscow 117071, Russia
| | - Mikhail V. Pridannikov
- Center of Parasitology of A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences, Leninskii Prospect 33, Moscow 117071, Russia
| | - Vlada Peneva
- Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences, 2 Gagarin Street, 1113 Sofia, Bulgaria
| | - Sergei A. Subbotin
- Center of Parasitology of A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences, Leninskii Prospect 33, Moscow 117071, Russia
- Plant Pest Diagnostic Center, California Department of Food and Agriculture, 3294 Meadowview Road, Sacramento, CA 95832, USA
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De Luca F, Archidona-Yuste A, Troccoli A, Fanelli E, Vovlas N, Trisciuzzi N, Castillo P. Redescription and molecular characterisation of Xiphinema barense Lamberti et al., 1986 (Nematoda: Longidoridae) from wild olive trees in southern Italy. NEMATOLOGY 2014. [DOI: 10.1163/15685411-00002836] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A population of Xiphinema barense from wild olive trees in Torre Pozzella, Brindisi province, southern Italy, is described using both morphological and molecular studies and compared with the description of the type specimens. The wild olive nematode population agrees very well with all morphometrics provided in the original description. However, detailed observations of the lumen of the tubular portion of the uterus in paratypes and specimens of the new population revealed a clear pseudo-Z-organ with small granules mixed with crystalloid bodies which were previously undetected. Photomicrographs of adult paratypes, which were lacking in the original description, and of specimens of the new population from wild olive trees are provided. The results of the phylogenetic analyses based on the sequences of the D2-D3 expansion regions of the 28S rRNA gene and ITS rRNA genes confirm the species differentiation and indicate the phylogenetic position of X. barense and its relationship with closely related species.
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Affiliation(s)
- Francesca De Luca
- Istituto per la Protezione Sostenibile delle Piante (IPSP), Consiglio Nazionale delle Ricerche (CNR), U.O.S. di Bari, Via G. Amendola 122/D, 70126 Bari, Italy
| | - Antonio Archidona-Yuste
- Institute for Sustainable Agriculture (IAS), Spanish National Research Council (CSIC), Campus de Excelencia Internacional Agroalimentario, ceiA3, Alameda del Obispo s/n, Apdo. 4084, 14080 Córdoba, Spain
| | - Alberto Troccoli
- Istituto per la Protezione Sostenibile delle Piante (IPSP), Consiglio Nazionale delle Ricerche (CNR), U.O.S. di Bari, Via G. Amendola 122/D, 70126 Bari, Italy
| | - Elena Fanelli
- Istituto per la Protezione Sostenibile delle Piante (IPSP), Consiglio Nazionale delle Ricerche (CNR), U.O.S. di Bari, Via G. Amendola 122/D, 70126 Bari, Italy
| | - Nicola Vovlas
- Istituto per la Protezione Sostenibile delle Piante (IPSP), Consiglio Nazionale delle Ricerche (CNR), U.O.S. di Bari, Via G. Amendola 122/D, 70126 Bari, Italy
| | - Nicola Trisciuzzi
- Centro di Ricerca, Sperimentazione e Formazione in Agricoltura (CRSFA) ‘Basile Caramia’, Via Cisternino 281, Locorotondo (BA), Italy
| | - Pablo Castillo
- Institute for Sustainable Agriculture (IAS), Spanish National Research Council (CSIC), Campus de Excelencia Internacional Agroalimentario, ceiA3, Alameda del Obispo s/n, Apdo. 4084, 14080 Córdoba, Spain
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Jones JT, Haegeman A, Danchin EGJ, Gaur HS, Helder J, Jones MGK, Kikuchi T, Manzanilla-López R, Palomares-Rius JE, Wesemael WML, Perry RN. Top 10 plant-parasitic nematodes in molecular plant pathology. MOLECULAR PLANT PATHOLOGY 2013; 14:946-61. [PMID: 23809086 PMCID: PMC6638764 DOI: 10.1111/mpp.12057] [Citation(s) in RCA: 805] [Impact Index Per Article: 73.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The aim of this review was to undertake a survey of researchers working with plant-parasitic nematodes in order to determine a 'top 10' list of these pathogens based on scientific and economic importance. Any such list will not be definitive as economic importance will vary depending on the region of the world in which a researcher is based. However, care was taken to include researchers from as many parts of the world as possible when carrying out the survey. The top 10 list emerging from the survey is composed of: (1) root-knot nematodes (Meloidogyne spp.); (2) cyst nematodes (Heterodera and Globodera spp.); (3) root lesion nematodes (Pratylenchus spp.); (4) the burrowing nematode Radopholus similis; (5) Ditylenchus dipsaci; (6) the pine wilt nematode Bursaphelenchus xylophilus; (7) the reniform nematode Rotylenchulus reniformis; (8) Xiphinema index (the only virus vector nematode to make the list); (9) Nacobbus aberrans; and (10) Aphelenchoides besseyi. The biology of each nematode (or nematode group) is reviewed briefly.
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Affiliation(s)
- John T Jones
- James Hutton Institute, Invergowrie, Dundee, DD2 5DA, UK
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Gutiérrez-Gutiérrez C, Cantalapiedra-Navarrete C, Remesal E, Palomares-Rius JE, Navas-Cortés JA, Castillo P. New insight into the identification and molecular phylogeny of dagger nematodes of the genusXiphinema(Nematoda: Longidoridae) with description of two new species. Zool J Linn Soc 2013. [DOI: 10.1111/zoj.12071] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Carlos Gutiérrez-Gutiérrez
- Institute for Sustainable Agriculture (IAS); Spanish National Research Council (CSIC); Apdo. 4084 Campus de Excelencia Internacional Agroalimentario ceiA3 14080 Córdoba Spain
| | - Carolina Cantalapiedra-Navarrete
- Institute for Sustainable Agriculture (IAS); Spanish National Research Council (CSIC); Apdo. 4084 Campus de Excelencia Internacional Agroalimentario ceiA3 14080 Córdoba Spain
| | - Efrén Remesal
- Institute for Sustainable Agriculture (IAS); Spanish National Research Council (CSIC); Apdo. 4084 Campus de Excelencia Internacional Agroalimentario ceiA3 14080 Córdoba Spain
- AGROCODE; Ctra. De Alicún, n°369 Ed. Natalia, 2°B, 04721 El Parador de Roquetas de Mar Almería Spain
| | - Juan E. Palomares-Rius
- Institute for Sustainable Agriculture (IAS); Spanish National Research Council (CSIC); Apdo. 4084 Campus de Excelencia Internacional Agroalimentario ceiA3 14080 Córdoba Spain
- Department of Forest Pathology; Forestry and Forest Products Research Institute (FFPRI); Tsukuba 305-8687 Ibaraki Japan
| | - Juan A. Navas-Cortés
- Institute for Sustainable Agriculture (IAS); Spanish National Research Council (CSIC); Apdo. 4084 Campus de Excelencia Internacional Agroalimentario ceiA3 14080 Córdoba Spain
| | - Pablo Castillo
- Institute for Sustainable Agriculture (IAS); Spanish National Research Council (CSIC); Apdo. 4084 Campus de Excelencia Internacional Agroalimentario ceiA3 14080 Córdoba Spain
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Gutiérrez-Gutiérrez C, Cantalapiedra-Navarrete C, Montes-Borrego M, Palomares-Rius JE, Castillo P. Molecular phylogeny of the nematode genusLongidorus(Nematoda: Longidoridae) with description of three new species. Zool J Linn Soc 2013. [DOI: 10.1111/zoj.12019] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Carlos Gutiérrez-Gutiérrez
- Institute for Sustainable Agriculture (IAS); Spanish National Research Council (CSIC); Campus de Excelencia Internacional Agroalimentario; ceiA3, Apdo. 4084 14080 Córdoba Spain
| | - Carolina Cantalapiedra-Navarrete
- Institute for Sustainable Agriculture (IAS); Spanish National Research Council (CSIC); Campus de Excelencia Internacional Agroalimentario; ceiA3, Apdo. 4084 14080 Córdoba Spain
| | - Miguel Montes-Borrego
- Institute for Sustainable Agriculture (IAS); Spanish National Research Council (CSIC); Campus de Excelencia Internacional Agroalimentario; ceiA3, Apdo. 4084 14080 Córdoba Spain
| | - Juan E. Palomares-Rius
- Institute for Sustainable Agriculture (IAS); Spanish National Research Council (CSIC); Campus de Excelencia Internacional Agroalimentario; ceiA3, Apdo. 4084 14080 Córdoba Spain
| | - Pablo Castillo
- Institute for Sustainable Agriculture (IAS); Spanish National Research Council (CSIC); Campus de Excelencia Internacional Agroalimentario; ceiA3, Apdo. 4084 14080 Córdoba Spain
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Sayler RJ, Walker C, Goggin F, Agudelo P, Kirkpatrick T. Conventional PCR Detection and Real-Time PCR Quantification of Reniform Nematodes. PLANT DISEASE 2012; 96:1757-1762. [PMID: 30727260 DOI: 10.1094/pdis-12-11-1033-re] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Reniform nematode (Rotylenchulus reniformis) is a relatively recent introduction into the continental United States that can cause major yield losses on a variety of important crops including cotton and soybeans. DNA sequences from the internal transcribed spacer (ITS) region of this nematode were used to design primers for conventional and real-time PCR, as well as a TaqMan probe. These primers amplified DNA of reniform nematode isolates from a wide geographic range but did not detect genetically related species or other pathogenic nematodes found in production fields including Meloidogyne incognita and Heterodera glycines. Both SYBR green and TaqMan assays reliably quantified as little as 100 fg of reniform nematode DNA, and could be used to quantify as few as five reniform nematodes. An inexpensive and rapid DNA extraction protocol for high throughput diagnostic assays is described.
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Affiliation(s)
- Ronald J Sayler
- Department of Plant Pathology, University of Arkansas, Fayetteville 72701
| | | | - Fiona Goggin
- Department of Entomology, University of Arkansas, Fayetteville 72701
| | - Paula Agudelo
- Clemson University, School of Agricultural, Forest, and Environmental Sciences, Clemson, SC 29634
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Gutiérrez-Gutiérrez C, Palomares-Rius JE, Cantalapiedra-Navarrete C, Landa BB, Esmenjaud D, Castillo P. Molecular analysis and comparative morphology to resolve a complex of cryptic Xiphinema species. ZOOL SCR 2010. [DOI: 10.1111/j.1463-6409.2010.00437.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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VILLATE L, ESMENJAUD D, COEDEL S, PLANTARD O. Development of nine polymorphic microsatellite markers for the phytoparasitic nematodeXiphinema index, the vector of the grapevine fanleaf virus. Mol Ecol Resour 2009; 9:229-32. [DOI: 10.1111/j.1755-0998.2008.02411.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Detection and quantification of root-knot nematode (Meloidogyne javanica), lesion nematode (Pratylenchus zeae) and dagger nematode (Xiphinema elongatum) parasites of sugarcane using real-time PCR. Mol Cell Probes 2008; 22:168-76. [PMID: 18378423 DOI: 10.1016/j.mcp.2008.01.003] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2007] [Revised: 01/19/2008] [Accepted: 01/23/2008] [Indexed: 11/23/2022]
Abstract
A number of different plant parasitic nematode species are found associated with sugarcane in South Africa. Of these, the root-knot nematode (Meloidogyne javanica), the lesion nematode (Pratylenchus zeae) and the dagger nematode (Xiphinema elongatum) are potentially the most damaging pests. Identification and enumeration of the number of these nematodes are necessary for providing advice to farmers as well as studying the effects of various treatments in field and glasshouse trials. We report on the development, use, and extent of specificity of three sets of primers, for M. javanica, P. zeae and X. elongatum, and on tests to detect and quantify the number of these nematodes in soil samples using SYBR Green I dye and real-time PCR technology. Amplicons from the three target species (obtained with their respective primer sets) are discernible in size by gel electrophoresis (380bp for M. javanica, 250bp for P. zeae and 500bp for X. elongatum). Also, these amplicons have characteristic melting temperatures of 83.8 degrees C (M. javanica), 86.6 degrees C (P. zeae) and 86.1 degrees C (X. elongatum). Investigations into multiplex reactions found competition between species with M. javanica competing with P. zeae and X. elongatum. Subsequent single tube (simplex) assays, enabled the construction of calibration curves for each of the three species. These were then used for quantification of the numbers of each of these species in nematode samples extracted from the field, with a high (R2=0.83) and significant positive correlation between real-time PCR and counts performed with microscopy.
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Demangeat G, Voisin R, Minot JC, Bosselut N, Fuchs M, Esmenjaud D. Survival of Xiphinema index in Vineyard Soil and Retention of Grapevine fanleaf virus Over Extended Time in the Absence of Host Plants. PHYTOPATHOLOGY 2005; 95:1151-1156. [PMID: 18943467 DOI: 10.1094/phyto-95-1151] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
ABSTRACT Grapevine fanleaf virus (GFLV) is transmitted specifically from grapevine to grapevine by the ectoparasitic root-feeding nematode Xiphinema index. Limited information is available on the survival of X. index in vineyard soil and on the retention of GFLV by X. index over extended periods of time. We addressed these two issues by quantifying the numbers of living X. index recovered from soil samples that were collected in three naturally GFLV-infected vineyards in France and subsequently stored at 7 or 20 degrees C in the absence of host plants. Our data indicated a two- to eightfold decrease in X. index numbers but the recovery of 8 to 10 living fourth-stage juveniles (J4) and adults per kilogram of soil after 4 years of storage regardless of temperature. In addition, GFLV was detected readily in all groups of 20 isolated X. index adults and J4 (except for J4 that were kept 4 years at 20 degrees C) by reverse transcription-polymerase chain reaction using total nematode RNAs and a primer set located in conserved regions at the 3' end of viral genomic RNA 2. Our findings on the long-term survival of viruliferous X. index under adverse conditions emphasize the need for new control strategies against GFLV.
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Abstract
Nematodes are considered among the most difficult animals to identify. DNA-based diagnostic methods have already gained acceptance in applications ranging from quarantine determinations to assessments of biodiversity. Researchers are currently in an information-gathering mode, with intensive efforts applied to accumulating nucleotide sequence of 18S and 28S ribosomal genes, internally transcribed spacer regions, and mitochondrial genes. Important linkages with collateral data such as digitized images, video clips and specimen voucher web pages are being established on GenBank and NemATOL, the nematode-specific Tree of Life database. The growing DNA taxonomy of nematodes has lead to their use in testing specific short sequences of DNA as a "barcode" for the identification of all nematode species.
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Affiliation(s)
- Tom Powers
- Department of Plant Pathology, University of Nebraska Lincoln, Lincoln, Nebraska 68583-0722, USA.
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