Optimising the tissue culture conditions for high efficiency transformation of indica rice

Establishment of high efficiency Agrobacterium-mediated transformation techniques has greatly accelerated the widespread application of transformation in japonica rice. However, transformation in indica rice remains difficult. In this study, we identify two new media for subculture and differentiation, the two major steps in the tissue culture process for transformation. These media were tested using four cultivars representing very different germplasms of indica rice. The results show that the new media significantly improved the growth rate and quality of the calli, and also increased the differentiation rate for all four cultivars tested. Use of these modified media in transformation experiments also greatly improved the transformation efficiency of all four indica cultivars.