[Generation of selectable marker-free and vector backbone sequence-free Xa21 transgenic rice].

The dominant gene Xa21 with broad-spectrum and high resistance to Xanthomonas oryzae pv. oryzae (Xoo) was transferred into C418, an important restorer line of japonica hybrid rice in China using double right-border (DRB) T-DNA binary vector through Agrobacterium-mediated transformation. 17 transgenic lines were Xa21-positive with high resistance to the race P6 of Xoo through PCR analysis and resistance identification, among the total 27 independent primary transformants (T0) obtained.