Use of PCR-based markers for identification of Erianthus genetic material in putative intergeneric hybrids (Saccharum x Erianthus)

Modern sugarcane varieties arose from interspecific crosses between Sacchar um officinarum and S. spontaneum varieties, and subsequent backcrossing to S. officinarum cultivars. Due to the lack of further genetic input, there h as been concern about an overall reduction in the pool of genes available f or improvement of sugarcane varieties. Therefore, breeders have looked to r elated genera such as Erianthus for introgression of novel genetic material into the germplasm. Little success has been achieved in introgression prog rammes carried out in the past few years, largely due to the difficulties e ncountered in the identification of true Saccharum x Erianthus hybrids usin g morphological traits. As a solution to this problem, PCR-based primers ha ve been developed which target 5s rDNA sequences shown to be polymorphic be tween the Saccharum and Erianthus genomes. This paper describes the use of these primers to detect the presence of Erianthus genetic material in vario us putative hybrids produced in breeding programmes at the Experiment Stati on. These results, confirmed with Restriction Fragment Length Polymorphism (RFLP) analysis, allow identification of true hybrids of Saccharum and Eria nthus, which may be used in the breeding programme for improving traits suc h as ratooning ability, vigour and tolerance to drought and flooding.