Evaluation of genetic variation among Indian populations of the pigeonpea cyst nematode, Heterodera cajani, by RAPD

One of the most important pathogen attacking pigeonpea root, the nematodeHeterodera cajani Koshy, is causing significant economic losses in India. Knowledge ofgenetic variability present among different geographical populations is important for theselection of suitable control strategies. Molecular diversity among ten populations of H.cajani in India from pigeonpea growing areas is demonstrated by random amplifiedpolymorphic DNA (RAPD). Operon series of decamer primers were used for exploringthe polymorphism. The number of amplified fragments per primer varied from 7 (withOPA 16 and OPD 4) to 24 (with OPB 2) whereas the size varied from 300 bp to 3.1 kb.Out of the 32 primers tested 23 revealed 100% polymorphism (OPA 1, 2, 3, 4, 5, 6, 10,OPB 2, 3, 4, 12, OPC 1, 4, 5, 7, 8, 9, 10, 11, 16, OPD 4 and 10). Overall, 451amplification products were obtained out of which, 434 were polymorphic and 17 weremonomorphic. The Jaccard’s coefficient and cluster analysis showed that the nematodepopulation from Indore was distinct from the other populations of H. cajani in India.Samastipur and Pusa R.S. populations showed high degree of similarity in thisexperiment.