Isozyme patterns of Heterodera avenae and H. filipjevi populations of India

Isozyme patterns of catalase (CAT), b-esterase (EST) and malate dehydrogenase (MDH) of white females of three populations of Heterodera filipjevi (pathotype Hf 31 and Hf 41) and five populations of H. avenae (pathotype ha 21) were studied using polyacrylamide gel electrophoresis. The two species could easily be differentiated on the basis of single band position of malate dehydrogenase that was at Rf 0.34 for H. filipjevi as compared to Rf 0.40 for H. avenae. Isozyme profiles of catalase and esterase, however, were not found useful for the separation of two species. A single band of catalase with Rf value of 0.26 was present in all the tested populations. Number of b-esterase bands were either three or two in these populations of cereal cyst nematode.