APPLICATION OF MITOCHONDRIAL-DNA POLYMORPHISM TO MELOIDOGYNE MOLECULAR POPULATION BIOLOGY

Recent advances in molecular biology have enabled the genotyping of in dividual nematodes, facilitating the analysis of genetic variability w ithin and among plant-pathogenic nematode isolates. This review first describes representative examples of how RFLP, RAPD, AFLP, and DNA seq uence analysis have been employed to describe populations of several p hytonematodes, including the pinewood, burrowing, root-knot, and cyst nematodes. The second portion of this paper evaluates the utility of a size-variable mitochondrial DNA locus to examine the generic structur e of Meloidogyne isolates using two alternate methodologies, variable number tandem repeat (VNTR) and repeat associated polymorphism (RAP) a nalysis. VNTR analysis has revealed genetic variation among individual nematodes, whereas RAP may provide useful markers for species and pop ulation differentiation.