PARAMETERS INFLUENCING STABLE TRANSFORMATION OF RICE IMMATURE EMBRYOSAND RECOVERY OF TRANSGENIC PLANTS USING ELECTRIC-DISCHARGE PARTICLE-ACCELERATION

Recovery of transgenic rice plants from elite varieties was reported f rom the authors' laboratory. By using electric discharge particle acce leration, recombinant technology was extended to commercially importan t japonica and indica rice cultivars not amenable to conventional tran sformation methodologies. Critical parameters influencing the recovery of transformed embryogenic callus from which transgenic plants were r ecovered have been defined. Such parameters included the physiological condition of explants prior to bombardment, DNA and gold particle loa ding rates, accelerating voltage, and depth of particle penetration. S election for recovery of stable transformants was not critical in this transformation/regeneration system; both selected and non-selected ti ssues yielded transformed embryogenic callus and plants at approximate ly similar frequencies.