Six isolates of Meloidogyne hapla, including four race A and two race B isolates, eight isolates of M. chitwoodi, and five isolates of M. fallax were submitted to two-dimensional gel electrophoresis (2-DGE) to study the similarity between the various isolates of the three species based upon total soluble proteins. For each isolate, two independent samples of 50 young egg-producing females were extracted from roots. Each sample was used to produce one mini 2-D gel. Mini 2-DGE showed an average of 400 protein spots per gel. Within each species, every gel was compared to all the others to identify two types of polymorphic spots: isoelectric point (IP) variants and present-absent (PA) variants. Thirteen PA and nine IP variants were observed among M. hapla isolates, eight PA and no IP variants among M. chitwoodi isolates, and two PA and no IP variants among M. fallax isolates, which represents 5.0, 2.2, and 0.6 % polymorphisms among isolates of the three respective species. These percentages imply small intraspecific variation within each of these species. They also confirm these species to be clearly delineated biological groups, as similarity between these species is significantly lower than similarity between isolates within each species (Van der Beek et al., unpubl.). Using UPGMA, the nine IP variants of M. hapla resulted in a similarity dendrogram, which clearly separated the race A isolates from the race B isolates.
|Journal||Fundamental and applied nematology|
|Publication status||Published - 1997|