Genome Characterization of In Vitro Induced Amphiploids of an Intergeneric Hybrid Erianthus arundinaceus × Saccharum spontaneum

Abstract

Erianthus arundinaceus, a wild relative of sugarcane, has great potential as a germplasm source to contribute valuable traits to sugarcane including better ratoonability, vigour and adaptation to biotic and abiotic stresses. Many unsuccessful attempts have been made to introduce the desirable characters from this wild species to modern sugarcane cultivars. In most of these cases, it was constrained by lack of fertility. A rare hybrid between E. arundinaceus (IK 76–78, 2n = 60) × Saccharum spontaneum (Iritty-2, 2n = 64) has been developed as an intermediate hybrid to transfer the characters from E. arundinaceus to sugarcane cultivars. This hybrid, CYM 04-420, with somatic chromosome number 2n = 62 was subjected to in vitro colchicine treatment, and amphiploids were developed with 2n = 124. We report here for the first time the chromosome composition and chromosome pairing behaviour of S. spontaneum × E. arundinaceus intergeneric amphiploid via genomic in situ hybridization. The implications of the results from this study for introgression of genes from E. arundinaceus in sugarcane breeding programmes are discussed in the paper.