RAPD-based polymorphism between cytoplasmic genic male sterile and restorer lines of pigeonpea

The cytoplasmic-genetic male sterility (CMS) system is considered to be feasible approach to develop hybrids in pigeonpea. Identification of CMS lines and their putative restorers using molecular markers in the early stage of growth is important and economical in pigeonpea. The RAPD analyses of genomic DNA were carried out using 80 RAPD primers in ten different genotypes each of A and R lines of pigeonpea. 76 of the 80 RAPD primers produced clear and unambiguous banding pattern among A and R lines. Out of these, 72 were polymorphic and 4 were monomorphic. A total of 702 bands were amplified, out of which 544 were polymorphic. This evinced on an average 7.55 polymorphic bands/primer; though the average number of amplified bands per primer were 8.77. The number of amplified loci varied from two each in OPC2, OPC12, OPB1, OPB5, OPB6 and OPB9 to twenty two in OPA 1 and OPA19. The size of amplified bands ranged from 100 bp to 2850 bp. The polymorphic 1.1kb fragment amplified by OPC1 was specific only to fertile (R) lines. The other specific fragment, confined only to sterile (A) lines, was of 1.5 kb size and was amplified by OPA11. However, this requires confirmation through linkage studies. The said RAPD primers are dominant in nature and would be more useful if they are converted in sequence based primers like SCAR.