Agrobacterium-mediated high frequency transformation in dwarf recalcitrant rice cultivars

The Agrobacteriann-mediated transformation was done in rice (Oryza sativa L. var. indica) cv. HKR126 and elite crossbred cv. Pusa Basmatil (PB1), using strain LBA4404 containing pCAMBIA1300 cloned with gene cassettes; potato proteinase inhibitor and Bacillus thuringiensis endotoxin (plasmid JDW53) or mannitol-1-phosphate dehydrogenase (plasmid RKJ108). Co-cultivation with scutellar-calli derived from mature seeds showed stable and highly efficient transformation. In cvs. HKR126 and PB1, 35 % and 41 % of hygromycin resistant calli were obtained. The transformation efficiency in PB1 (22.0 %) was much higher than in HKRl26 (12.5 %). Similarly, PB1 had higher plant regeneration efficiency than HKR126. The shoots regenerated per callus were, 3 - 4 in HKR126 and 5 - 6 in PB1. The transformation efficiency with pRKJ108 (18.6 %) was higher than pJDW53 (15.9 %). Polymerase chain reaction (PCR) analysis showed the presence of transgenes in regenerated transgenic plants of both cultivars.