Diagnostic set of microsatellite markers for hybrid purity testing and molecular identification of hybrids and parental lines in sorghum

Ten sorghum hybrids (seven kharif, two dual purpose and one rabi types) along with their thirteen parental lines were utilized for molecular identification and hybrid purity testing in the present study. Ten out of 11 microsatellite (or SSRs-simple sequence repeats) markers used were polymorphic (90.9%) with 2 to 6 alleles (average 3.4 alleles) and PIC (Polymorphism Information Content) value ranged from 0.28 to 0.61. All the ten polymorphic markers revealed polymorphism between the male and female parents of one or more hybrids and would be useful for their hybridity testing. Further, Sb5-236 and Sb4-15 have been identified as the two diagnostic markers for the genetic purity testing of all the ten sorghum hybrids included in this study. Sb6-42, Sb4-22 and Sb5-236 individually or a combination of Sb6-42/Sb4-22 and Sb5-236 could distinguish three and five hybrids respectively and can be used as referral set of markers for identification and protection of sorghum hybrids (CSH 13, CSH 15R, CSH 1, CSH 14 and SPH 837). All the kharif/dual purpose and rabi sorghum hybrids were grouped in separate clusters. Diagnostic/referral set of SSR markers will aid in hybrid breeding programme of sorghum.