Choice of microsatellite markers for isolation of fertility restorers of wild abortive (WA) type cytoplasmic male sterility in rice

Abstract

Simple sequence length polymorphism was examined in a set of eight effective restorers, four partial restorers, two weak maintainers and four complete maintainers of WA type CMS system in rice using a set of thirty-two microsatellite primer pairs in order to assess the nature and extent of genetic variation among them at molecular level. Altogether 248 allelic variants were detected with an average of 7.75 alleles per primer pairs. Polymorphic information content ranged from 0.508 for RM 6737 to 0.882 for RM 1 with an average value of 0.740 per primer pair. Amongst the primer pairs used, RM 1, RM 206, RM 591 RM 3873 and RM 8146 had remarkably higher number of allelic variants with greater gene diversity and genotype discrimination ability. Using similarity coefficient in numerical taxonomic approach of classification, the entries were differentiated and classified into different groups. Analysis based on molecular profiles allowed discrimination of effective fertility restorers from rest of the entries including partial fertility restorers, weak sterility maintainers and complete sterility maintainers. Principal coordinate analysis based two dimensional plotting of genetic profiles completely supported the results obtained from hierarchical classification of entries and effective fertility restorers were distinctly discriminated from the remaining entries. Four microsatellite primer pairs namely, RM 171, RM 315, RM 3873 and RM 6100, which allowed unambiguous discrimination of the eight effective fertility restorers from rest of the entries. These microsatellite primer pairs, may be further utilized in identification of effective fertility restorers of WA based CMS system in rice.