Comparison of Populations of Pratylenchus brachyurus Based on Isozyme Phenotypes.

Enzymes from females of five Pratylenchus brachyurus populations and one P. scribneri population were analyzed by isoelectric focusing electrophoresis. Of the 18 enzyme systems investigated, only malate dehydrogenase (MDH), phosphoglucomutase (PGM), and phosphoglucose isomerase (PGI) were detected from all five P. brachyurus populations and P. scribneri. Faint bands were detected for isocitrate dehydrogenase and phosphogluconate dehydrogenase from one P. brachyurus population. Three distinct phenotypic groups were found in the MDH and PGM systems for P. brachyurus populations, but only a single electromorph was detected for PGI. Multiple electromorphs for MDH, PGM, and PGI were detected for P. scribneri; there was no similarity among these patterns with those from P. brachyurus. No phenotypic differences in PGI were observed between females and mixed juveniles of one population of P. brachyurus.