[A genetically modified japonica restorer line, C418-Xa21, and its hybrid rice with bacterial blight resistance].
摘要
The cloned bacterial blight (BB) resistance gene Xa21 was transferred into C418, a major restorer line of japonica hybrid rice in China, using an Agrobacterium-mediated system. The integrated single copy of transgene displayed a 3:1 segregation ratio in T1 generation in PCR and resistance analyses. The transgenic homozygous C418-Xa21 lines were selected in T2 generation through PCR and resistance analyses. The selected transgenic restorer lines were then crossed with a commonly used sterile line, TijinA, to produce Xa21 transgenic hybrid rice. Molecular analysis revealed that the produced hybrid rice, named as Tiyou418-Xa21, inherited the transgene. Both C418-Xa21 and Tiyou418-Xa21 plants displayed high resistance with a broad spectrum to Xoo races and maintained their normal elite agronomic characters. We also observed that the resistance level of Tiyou418-Xa21 was obviously higher than that of C418-Xa21 which may be attributed to their differences in genetic background. The propagation of this BB resistant hybrid variety with the transgene Xa21 with extend hybrid rice production in north China.