A Rapid Technique for Esterase and Malate Dehydrogenase Analysis from Cyst and Root-Knot Nematodes

A simple and rapid method of determining esterase (Est) and malate dehydrogenase (Mdh) activities from cyst nematode, Heterodera zeae and root-knot nematode, Meloidogyne incognita was developed. The technique involved extraction of both the enzymes by a simple isolation buffer comprising of sucrose and L-ascorbic acid (pH 7.4). This was followed by alkaline polyacrylamide gel electrophoresis using 8% running and 3% spacer gels and a constant current of 1.5 m AMP/well till the tracking dye crossed the stacking gel and 2 m AMP/well thereafter. Esterase patterns of widely divergent populations of H. zeae from Delhi and Bihar exhibited 4 clear bands. Mdh isozymes of H. zeae from Delhi, Jammu, Panipat and Sonipat populations revealed only 2 bands of activities. Two major bands of esterase and 1 of MDH were discernible in M. incognita populations from Bangalore and Delhi. The studies revealed that although the technique could be employed successfully to analyze the isozyme phenotypes of esterase and Mdh, these enzymes did not distinguish the test cyst and root-knot nematode populations from bio-diverse origin.