水稻无选择标记 Xa21转基因系 CX8621的获得与遗传分析

摘要

无选择标记和转基因稳定遗传是转基因作物安全应用的基本要求.按照我国转基因作物安全评价指南,利用双右边界 T-DNA 载体系统将广谱抗白叶枯病基因 Xa21转入水稻恢复系明恢86.通过抗性鉴定、PCR 分析和 Southern 杂交,跟踪了外源 Xa21基因在转基因后代植株的遗传,并在 T3代获得了无选择标记和载体骨架序列的单拷贝抗病纯合系CX8621.多年的观察和鉴定表明转基因恢复系 CX8621具有稳定的白叶枯病抗性.目前 CX8621已经稳定遗传至 T16,并已通过小规模的田间试验(环境释放)和大规模的田间试验(生产性试验)的安全评价.%Selectable marker-free and stable inheritance are the basic requirements for safe application of transgenic crops.Following the regulations approved by the National Committee for Transgenic Biosafety,the wide spectrum bacterial blight resistance gene Xa21 was transferred into a widely used restorer line Minghui 86 by using a double right-borders T-DNA vector through Agrobacterium tumefaciens-mediated system.The transgene Xa21 was confirmed by resistance identification,PCR analysis and Southern blot in the progenies.The single-copy homozygous transgenic line CX8621 without selectable marker and vector backbone sequences was obtained from T3 generation.The transgenic restorer line CX8621 has stable bacterial blight resistance with years of observation and identification.Up to now, CX8621 has self-fertilized to 1 6th generation with stable inheritance of transgene Xa21 and passed the bio-safety evaluation of small and large scale of field tests (environmental release and productive test).