TRANSGENIC INDICA RICE BREEDING LINE IR58 EXPRESSING A SYNTHETIC CRYIA(B) GENE FROM BACILLUS-THURINGIENSIS PROVIDES EFFECTIVE INSECT PEST-CONTROL

The Indica rice breeding line IR58 was transformed by particle bombard ment with a truncated version of a synthetic cryIA(b) gene from Bacill us thuringiensis. This gene is expressed under control of the CaMV 35S promoter and allows efficient production of the lepidopteran specific delta-endotoxin. R(0), R(1) and R(2) generation plants displayed a si gnificant insecticidal effect on several lepidopterous insect pests. F eeding studies showed mortality rates of up to 100% for two of the mos t destructive insect pests of rice in Asia, the yellow stem borer (Sci rpophaga incertulas) and the striped stem borer (Chile suppressalis), and feeding inhibition of the two leaffolder species Cnaphalocrocis me dinalis and Marasmia patnalis. Introduction of stem borer resistance i nto the germplasm of an Indica rice breeding line now makes this agron omically important trait available for conventional rice breeding prog rams.