CHARACTERISATION OF SUGARCANE X Erianthus arundinaceus HYBRIDS USING PCR AND IN SITU HYBRIDISATION

¹ Bureau of Sugar Experiment Station PO Box 86 Indooroopilly Q 4068 Australia

² 1/38 Walker St Townsville Q 4810 Australia

³ Department of Biochemistry The University of Queensland St Lucia Q 4072 Australia

⁴ Bureau of Sugar Experiment Station PO Box 122 Gordonvale Q 4865 Australia

⁵ CIRAD Avenue du Val de Montferrand BP 5035 34032 Montpellier France

Erianthus arundinaceus is a species related to sugarcane with desirable attributes including excellent vigour and ratooning, adaptability to environmental stresses such as moisture deficits and excesses, and resistance to Pachymetra root rot. Numerous attempts have been made to cross E. arundinaceus with sugarcane to introduce these characters into modern cultivars. However, no conclusive results have been achieved to date. Indeed, in only a few cases has conclusive evidence of true intergeneric hybrids been documented (D’Hont et al., 1995; Besse et al., 1997; this study). These hybrids were produced from crosses involving pure Saccharum officinarum (2n=80) as the female parent and E. arundinaceus as the pollen donor. One of the major obstacles in using E. arundinaceus in the past has been the identification of true hybrids using morphological characters, which is time-consuming and unreliable. Molecular diagnostic tools have recently been developed for use in sugarcane to overcome this difficulty (D'Hont et al., 1995). These tools include sequence-tagged PCR to identify true hybrids at the seedling stage, and genomic in situ hybridisation (GISH) to characterise the chromosome complement of these genuine hybrids. An introgression program involving Erianthus commenced several years ago at the Bureau of Sugar Experiment Stations (BSES) in Australia. Here we report on the significant progress achieved in this program since these molecular tools were implemented.