<span style="font-size:11.0pt;font-family: "Times New Roman";mso-fareast-font-family:"Times New Roman";mso-bidi-font-family: Mangal;mso-ansi-language:EN-GB;mso-fareast-language:EN-US;mso-bidi-language: HI" lang="EN-GB">Genetic fingerprinting of A and R lines of pigeonpea [<i>Cajanus cajan</i> (L.) Millsp.] using RAPD and SSR markers</span>

Abstract

The cytoplasmic-genetic male-sterility (CGMS) system is a potent approach to develop hybrids in pigeonpea [<i>Cajanus cajan</i> (L.) Millsp.]. The CGMS system comprises of three lines, <i style="mso-bidi-font-style:normal">viz.,</i> A (sterile), B (maintainer) and R (restorer) lines. Practically identification of CGMS lines and their putative restorers in the early stage of growth is desired using molecular markers. The RAPD and SSR analyses of genomic DNA were performed using 80 RAPD and 123 SSR primers in 10 distinct genotypes of each of A and R lines of pigeonpea. Of 80 RAPD primers used, 76 of them produced blatant banding pattern among A and R lines. Out of these, 72 were polymorphic and 4 were monomorphic. A total of 702 bands were amplified, of which 544 were polymorphic. The number of amplified loci varied from 2 to 22, while the size of amplified bands ranged from 100 to 2850 bp. Out of 123 SSR primers used, 94 showed amplifications and only 67 primers evinced polymorphism in A and R lines, indicating 54.47 per cent polymorphism. Further, 183 alleles were amplified on the said 94 SSR loci with an average number of 1.98 alleles per locus and the size of the amplified fragments varied from 100 to 2950 bp. The Jaccard and Nei’s similarity coefficient ranged from 0.58 to 0.79 for RAPD and 0.24 to 0.93 for SSR. A dendrogram constructed based on the UPGMA clustering method using RAPD primers revealed two major clusters, while SSR markers showed four major clusters. Of 80 RAPD marker, two marker, <i>viz</i>., OPC1 and OPA 11, exhibited informative bands specific to CMS and restorer lines, respectively. Thus RAPD seemed better option for easy screening of A and R lines in Pigeonpea.