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

Recovery of transgenic rice plants from elite varieties was reported from the authors' laboratory. By using electric discharge particle acceleration, recombinant technology was extended to commercially important japonica and indica rice cultivars not amenable to conventional transformation methodologies. Critical parameters influencing the recovery of transformed embryogenic callus from which transgenic plants were recovered have been defined. Such parameters included the physiological condition of explants prior to bombardment, DNA and gold particle loading rates, accelerating voltage, and depth of particle penetration. Selection for recovery of stable transformants was not critical in this transformation/regeneration system; both selected and non-selected tissues yielded transformed embryogenic callus and plants at approximately similar frequencies.