title: Intraspecific variability of the facultative meiotic parthenogenetic root-knot nematode (Meloidogyne graminicola) from rice fields in Vietnam.
abstract: Twenty years ago, the facultative meiotic parthenogenetic root-knot nematode (RKN), Meloidogyne graminicola, was recognised as an important rice pathogen in South Vietnam. Although this country is one of the most important rice exporters worldwide, a comprehensive picture of the occurrence of M. graminicola in Vietnamese rice fields is still not available. Therefore a nematode survey was carried out with the aim of better understanding the geographical distribution, and the pathogenic and genetic variability of the RKN in Vietnam. From the fields surveyed in a range of ecosystems, 21 RKN populations were recovered from infected rice roots. A diagnostic SCAR marker was developed showing that all Vietnamese populations belong to M. graminicola. Furthermore, sequencing of the Internal Transcribed Spacer (ITS) of the rDNA genes confirmed this identification. These populations were then characterised using morphometrics and pathogenicity tests (host plant range diversity, reproduction and virulence diversity) revealing intraspecific variability. We showed that morphometric traits are mainly genetically heritable characters with significant differences among the studied populations. Finally, a distinctive trait signature was found for the populations isolated from the upland rice cultures. All together, our study reveals the prevalence of M. graminicola populations in Vietnamese rice. Further investigations need to be developed to explore the population dynamics and evolutionary history of this species in South East Asia.
authors.affiliation: IRD Institut de recherche pour le développement, UMR 186 "Résistance des plantes aux bioagresseurs", 911, avenue Agropolis, BP 64501, 34394 Montpellier cedex 5, France; IRD, LMI RICE, University of Science and Technology of Hanoi, Agricultural Genetics Institute, Hanoi, Viet Nam. Electronic address: stephane.bellafiore@ird.fr.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Bellafiore
authors.affiliation: IRD Institut de recherche pour le développement, UMR 186 "Résistance des plantes aux bioagresseurs", 911, avenue Agropolis, BP 64501, 34394 Montpellier cedex 5, France.
authors.forename: Claire
authors.initials: C
authors.lastname: Jougla
authors.affiliation: IRD Institut de recherche pour le développement, UMR 186 "Résistance des plantes aux bioagresseurs", 911, avenue Agropolis, BP 64501, 34394 Montpellier cedex 5, France.
authors.forename: Élodie
authors.initials: É
authors.lastname: Chapuis
authors.affiliation: CNRS-UPS-ENFA, UMR5174, EDB (Laboratoire « Évolution & diversité biologique »), 118, route de Narbonne, 31062 Toulouse, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Besnard
authors.affiliation: IRD Institut de recherche pour le développement, UMR 186 "Résistance des plantes aux bioagresseurs", 911, avenue Agropolis, BP 64501, 34394 Montpellier cedex 5, France; IRD, LMI RICE, University of Science and Technology of Hanoi, Agricultural Genetics Institute, Hanoi, Viet Nam.
authors.forename: Malyna
authors.initials: M
authors.lastname: Suong
authors.affiliation: IRD Institut de recherche pour le développement, UMR 186 "Résistance des plantes aux bioagresseurs", 911, avenue Agropolis, BP 64501, 34394 Montpellier cedex 5, France; Department of Biotechnology, Nong Lam University, Ho Chi Minh City, Viet Nam.
authors.forename: Phong Nguyen
authors.initials: PN
authors.lastname: Vu
authors.affiliation: Laboratory of Tropical Crop Improvement, Department of Biosystems, Faculty of Bioscience Engineering, University of Leuven (KU Leuven), Willem de Croylaan 42, 3001 Heverlee, Belgium; International Rice Research Institute (IRRI), DAPO Box 7777, Metro Manila, Philippines; Unit for Environmental Sciences and Management, North-West University, Private Bag X6001, 2520 Potchefstroom, South Africa.
authors.forename: Dirk
authors.initials: D
authors.lastname: De Waele
authors.affiliation: IRD, LMI RICE, University of Science and Technology of Hanoi, Agricultural Genetics Institute, Hanoi, Viet Nam; University of Montpellier-2, UMR DIADE, Montpellier, France.
authors.forename: Pascal
authors.initials: P
authors.lastname: Gantet
authors.affiliation: Department of Plant Pathology, Faculty of Agronomy, Hanoi University of Agriculture Trau Qui, Gia Lam, Hanoi, Viet Nam.
authors.forename: Xuyen Ngo
authors.initials: XN
authors.lastname: Thi
mesh_terms: D000818:Animals; D018509:DNA, Helminth / Q000235:genetics*; D008969:Molecular Sequence Data; D012275:Oryza / Q000469:parasitology*; D018517:Plant Roots / Q000469:parasitology*; D013045:Species Specificity; D014431:Tylenchoidea / Q000235:genetics* / Q000472:pathogenicity; D014744:Vietnam
chemical_list: D018509:DNA, Helminth
keywords: Intraspecific variability; Meloidogyne graminicola; Rice; SCAR; Vietnam