Genetic Variation among Parthenogenetic Meloidogyne Species Revealed by Aflps and 2D-Protein Electrophoresis Contrasted to Morphology

Isolates of the ameiotic parthenogenetic species Meloidogyne are?zaria, M. hapla race B, M. incognita, and M. java nica and of the meiotic parthenogenetic species M. chitwoodi, M. fallax, M. hapla race A, and M. naasi were compared for total soluble proteins using two-dimensional gel electrophoresis (2-DGE), total genomic DNA using electrophoresis of amplified fragment length polymorphisms (AFLP), and morphological characters by morphometric measurements and from literature. Data sets were converted to similarity coefficients using the Dice coefficient, based on more than 100 protein spots, 192 AFLP fragments, and 21 morphological characters. UPGMA dendrograms based on protein and DNA data were congruent: with both types of data, M. hapla race A and race B clustered together, the three tropical species M. incognita, M. javanica, and M. arenaria formed another cluster, and the species specialized on Gramineae -M. naasi, M. chitwoodi, and M. fallax- were distant from the rest, with high similarity between M. chitwoodi and M. fallax. The dendrogram for morphological data was different from the dendrograms for molecular data, particularly for M. incognita and M. naasi. The reasons for this discrepancy between protein and DNA studies on the one hand and morphological studies on the other hand are discussed. (C) Orstom/Elsevier, Paris.