TISSUE CULTURE AND BIOLISTIC TRANSFORMATION OF NEW SMUT RESISTANT SUGARCANE VARIETIES

THE SMUT susceptible sugarcane cultivar Q117 has been the main commercial variety used for routine transformation research in Australia. With the recent smut incursion however, it is imperative that all future genetic modification (GM) research leading to commercial GM crop development should use smutresistant varieties. To this end, we recently initiated research to develop and establish routine tissue culture and transformation systems for important smutresistant Australian cultivars KQ228A, Q200A and Q208A. Initial experiments tested the production of embryogenic callus using only 2,4-dichlorophenoxyacetic acid (2,4-D) at various concentrations in the tissue culture medium. However, biolistic transformation efficiency of this callus was very low. We therefore tested performance of these three varieties in various combinations of naphthalene acetic acid (NAA) and either chlorophenoxy acetic acid (CPA) or 2,4-D in the culture medium. Results of the tissue culture experiments indicated that the addition of CPA in the culture medium was not suitable for the production of embryogenic callus in any of the three varieties studied. We have identified certain combinations of NAA and 2,4-D which produced prolific embryogenic callus. These media are being tested for the genetic transformation of the smut resistant varieties. One major problem with these new smut resistant varieties is precocious germination while still in the dark. This aspect of the work needs to be optimised further before any routine transformation experiments can be developed and implemented.