Genetic structure and diversity within local populations of Meloidogyne (Nematoda: Meloidogynidae)

Abstract

AbstractA survey of Meloidogyne in La Vera (Spain) was carried out during October 1995 and 1997. Isozyme electrophoresis (A-EST, MDH, CAT, GPI, DIA, GOT and SOD) was performed for each nematode isolate, each of which was cultured from an egg mass. In 1995 seven isolates of M. incognita, two of M. javanica and 75 of M. arenaria were found, while in 1997 one isolate of M. javanica and 72 of M. arenaria were found. Taxonomic relationships were established among 151 isolates using enzyme phenotypes by means of Multiple Correspondence and UPGM analysis. Twenty-six Multilocus Enzyme Electrophoresis (MLEE) phenotype variants were detected in ten significant taxonomic units: M. arenaria (seven units), M. incognita (two) and M. javanica (one). A total of 13 loci were identified and allelic frequencies for MLEE phenotype variants were estimated. Genetic distances among them suggested that M. arenaria is a poly- or paraphyletic group formed by at least two or three monophyletic lines of different origins. The evolutionary and epidemiological implications are discussed.