Host preference of six geographical isolates of reniform nematode, Rotylenchulus reniformis

The host preference of six geographical isolates of Rotylenchulus reniformis were studied using cotton var, H-777, cowpea var. Pusa Komal, castor var. Ch-1, bajra var. Pusa-23 and mustard var. Pusa Bold. The isolates of R. reniformis used were Andhra Pradesh grape (AP-1) Andhra Pradesh castor (AP-2), Delhi grape (DL-1). Delhi castor (Dl-2),Gujarat castor (Gj-1) and Manipur pineapple (MN-1) isolate. The populations of these isolates were maintained on castor which served as source of inoculum for studying their reproduction variabilities. All the isolates could reproduce on cotton, castor and cowpea, but differed in their reproduction behaviour towards bajra and mustard. The existence of four physiological variants was indicated, being represented by (i) AP-1 and MN-1 isolate which did not renroduce on baira, mustard (ii) AP-2 and GJ-1 isolates which reproduce on bajra, but not on mustard (iii) DL-2 isolate which reproduce on mustard and not on bajra and (iv) DL-1 isolate which reproduced on both bajra and mustard.