T—DNA插入水稻群体中卷叶突变体R1—A2的遗传分析

在根癌农杆菌介导的T-DNA(携带有除草剂Basta抗性基因bar和Ds因子)转化中花11水稻群体中，获得了一个叶片发生明显内卷的突变体Rl-A。经过连续三代的分离鉴定，获得突变体的纯合株(Rl-A2)，并与中花11号进行杂交，在调查的36个F1植株中，全部表现为卷叶，并对Basta除草剂都表现为抗性。在852个F2单株中，卷叶为645株，正常叶207株，卷叶和正常叶的比例为3：1，其中，卷叶株均对Basta表现抗性，正常叶株均对Basta表现敏感，表明卷叶性状和Basta抗性存在着共分离关系。用扩增DS因子的引物，对F2中45个卷叶抗性株进行PCR鉴定，都获得预期长度的Ds因子片段，进一步表明在这些卷叶的植株中都有T-DNA的插入；而30个正常叶敏感株都不能检测到DS的特征片段。在以卷叶突变(Rl-A2)为回交亲本的F1B1植株中，全部植株表现卷叶；在以中花11号为回交亲本的F1B1植株中，卷叶和正常叶植株的分离比为1：1。上述结果表明该卷叶突变是个显性突变，受一个基因所控制，且该基因的突变与T-DNA的插入有关。

Genetic analysis of a rolled-leaf mutant in rice population of T-DNA insertion]

A rolled-leaf mutant was obtained in a T-DNA(containing bar gene and Ds element) insertion population, which consist of transgenic japonica rice Zhonghua 11 mediated by Agrobacterium tumefaciens. Through self-hybridization of three generations, one of trait-purified mutants (R1-A2) was obtained and used as parent to cross with variety Zhonghua 11. The leaves of 36 F1 plants investigated were rolled and resistant to herbicide Basta. Among 852 F2 plants, the segregation ratio of rolled leaves to normal leaves(645:207) was consistent with 3:1. All rolled-leaf plants were resistant to herbicide Basta, and all normal leaf plants were sensitive to herbicide Basta. These results showed that the trait of rolled-leaf is co-segregated with Basta resistance. The total DNA of 45 rolled-leaf plants and 30 normal leaf plants in F2 population were amplified to test the presence of T-DNA by Ds primers. The results showed that the positive band were amplified in all rolled-leaf plants, but not in every normal leaf plant. In F1B1 progenies, all plants which derived from backcross parent R1-A2 were rolled leaves; while variety Zhonghua 11 was used as backcross parent, the segregation ratio of rolled-leaf to normal leaf was consistent with 1:1. Taking these data together, it indicated that the rolled-leaf mutant was co-segregation with T-DNA and controlled by single dominant gene.