Genetic Polymorphism in Four Geographically Diverse Meloidogyne incognita Populations in India

A rapid and precise random amplified polymorphic DNA (RAPD) diagnostic was developed and used to discriminate four geographically diverse populations of Meloidogyne incognita The four populations isolated from north (bnnjal - Delhi), south (tomato - Bangalore,), east (okra - Bhubaneswar) and western (cowpea - Anand) parts of India These populations were maintained in both glass house and on excised tomato roots DNA was extiacted by hand crushing second stage juveniles directly in Tns-EDTA buffer (T10 El) in a ground glass extraction appaiatus The technique was as efficient as the modified mini-prep method. The four test populations from divergent agro-climatic conditions appeared to be particularly different in their RAPD profiles. Fiom one to eight fragments of size ranging from 200 to 1400 base pairs were obtained with each of the 5 selected primers out of 36 decamer primers tested. The reaction with OPC-15 produced reproducible and amplified bands whose size allowed distinction of all the four test populations of M incognita