Root-knot nematodes (Meloidogyne spp.) are important polyphagous plant
parasites worldwide. Intraspecific variation and the occurrence of physiological
races have necessitated the development of taxonomic techniques enabling
differentiation and classification of races related to major Meloidogyne spp.
Accurate identification of their races and populations is essential for determining
appropriate management approaches and benefits from further characterization and
understanding of the variability within a single nematode species. Electrophoretic
focusing of malic dehydrogenase, α-glycerophosphate dehydrogenase and
esterase for seven populations of Meloidogyne spp. by polyacrylamide gels was
tested. These populations included 1, 2 and 4 populations of M. javanica and M.
arenaria race I and II, respectively. Malic Dehydrogenase profiles obtained by
polyacrylamide-gel electrophoresis indicated that differences between Meloidogyne
arenaria and M. javanica were more pronounced than were differences between
races or populations of M. arenaria. The enzyme patterns of the two species varied
even though the nematodes were propagated on the same host plant (Rutgers
tomato).