Identification of intergeneric hybrids between Erianthus arundinaceus and Saccharum spontaneum through STMS markers

Erianthus arundinaceus, a genus in Saccharum complex with high biomass production and resistance to biotic stresses is one of the potential candidates to broaden the genetic base of modern sugarcane varieties. Except some advancements reported on Erianthus introgression in India and Australia, attempts in the past four decades did not result in significant progress due to the inherent difficulty in making such crosses, transmission of n+n gametes and hybrid sterility. Saccharum spontaneum was used as bridge species to overcome these barriers but identification of true intergeneric hybrids with morphological markers was difficult. Fifteen sugarcane genome specific STMS markers were successfully used in identifying four suspected hybrids between two S. spontaneum (SES 286 -SS1 and SES 571 -SS2) and one Erianthus arundinaceus (IK 76-92-EA). Among the 15 primers used, 13 and 12 were polymorphic between EA and SS1 and EA and SS2 respectively. The polymorphic markers ranged from 1 (NKS 12, 46) to 12 (NKS 21) among the progeny of EA x SS1 and 2 (NKS 45, 15, 38, 40) to 7 (NKS 23) among the progeny of EA x SS2. While the hybrid nature of three progeny of the cross EA x SS1 was confirmed by the distinct presence of 57, 53 and 56 male specific markers respectively, hybrid nature of the progeny between EA x SS2 was confirmed by the presence of 42 male specific markers. The study clearly demonstrated the efficiency of STMS markers to generate large polymorphism and identification of true hybrids.