Optimization of Agrobacterium-Mediated Genetic Transformation in indica Rice

This experiment was conducted during the period from August 2004 to April 2005 in the Biotechnology & Genetic Engineering Laboratory of the Department of Genetics and Plant Breeding, Bangladesh Agricultural University, Mymensingh. In this experiment, an efficient and reproducible protocol for the production of transgenic rice plants was developed by inoculating mature embryo of three indica rice genotypes with Agrobacterium tumefaciens strain LBA4404 carrying a binary vector pBI121, which contains selectable marker gene nptII conferring resistance to kanamycin and the GUS reporter gene. The transformation experiment was performed by optimizing two important parameters: infection time and co-cultivation period. Infection was most effective when explants were inoculated for 15 minutes (72.59% GUS positive) and co-cultivated for four days (70.37% GUS positive) with Agrobacterium. Among the varieties, BRRI dhan-33 showed the highest response to GUS assay (65.33% GUS positive). Transformation percentage (putative) was also highest in BRRI dhan-33 (4%). 10 minutes infection time and co-cultivation period of three days was found effective for regeneration of shoots (2.45% and 4.45%, respectively). Among the varieties, BRRI dhan-33 produced the highest percentage (61.11%) of rooted shoots.