摘要
以含非翻译马铃薯Y病毒外壳蛋白 (PVY MCP)基因的抗病和感病T0 代转基因烟草为材料 ,对转基因及RNA介导的病毒抗性在T1～T4代转基因植株中的遗传进行了研究。结果表明 ,在含低拷贝 (1～ 2个 )转基因的感病植株后代中 ,转基因是作为一个单显性遗传位点 ,遵循孟德尔遗传分离规律 ,各世代转基因植株仍表现感病。含多拷贝 (4～ 6个 )转基因的抗病植株 ,转基因在T1代的分离虽符合多位点插入的 15∶1和 6 3∶1遗传规律 ,但转基因发生了重排 ,RNA介导的病毒抗性表现为不稳定遗传。从含多拷贝转基因的抗病植株的T1代株系中 ,分离获得了两株含 2个拷贝转基因的抗病植株 ;其后代中 ,转基因及抗性遗传遵循孟德尔遗传分离规律 ,可稳定遗传和表达 ,获得纯合的抗病转基因株系。对转基因在不同抗病类型植株中整合方式分析显示 。
RNA-mediated virus resistance is an effective way to obtain virus resistant plants and is regarded as a potential strategy with application value in plant resistant virus breeding because of its advantage of high bio-safety and long duration.Whether the resistance can inherit stably is a critical factor affecting its application in agriculture.In this paper,several T_0 progeny transgenic plants with different resistant levels and with different transgene copy numbers were selected for further study.The results showed that the inheritance of the transgene in T_0 susceptible transgenic plants containing 1～2 transgene copies followed Mendelian segregation pattern of single gene inheritance in their progenies.Resistant transgenic plants,which contained 4～6 transgene copies,followed 15∶1 and 63∶1 segregation patterns in the T_1 progeny.Transgene recombination and re-organization in the plant genome was observed,which resulted in unstable inheritance of the transgene in the progenies.Homozygous resistant transgenic plants were obtained after 3 to 4 generations in the progeny.Analysis of the transgene integration pattern indicated that most of the highly resistant plants contained inverted repeat (IR) sequences of the transgene.
基金
国家自然科学基金 (编号 :3 0 2 70 875 )
山东省自然科学基金 (编号 :Q2 0 0 1D0 1)资助~~
