AN EFFICIENT TRANSFORMATION SYSTEM FOR THE AUSTRALIAN RICE CULTIVAR, JARRAH

A rapid and efficient transformation system for the generation of larg e numbers of transformed, fertile, transgenic rice (Oryza sativa L.) p lants of the Australian rice cultivar, Jarrah, is described. Embryogen ic callus pieces derived from mature seeds were bombarded with gold pa rticles coated with DNA. Two plasmids were used, one containing a gene encoding hygromycin phosphotransferase (hph, conferring hygromycin re sistance) as a selectable marker and the other containing uidA (gus) a s a reporter gene. The calli were selected for their resistance to hyg romycin. DNA uptake, integration and expression of the hph and gus gen e in selected rice were investigated by various PCR methods and dot bl ot and Southern analysis of genomic DNA extracted from transformed ric e plants. On average one independently transformed hygromycin resistan t plant was recovered from every 2.4 pieces of callus bombarded. Selec tion with Biolaphos using the Bar gene as selectable marker was not su ccessful in this system.