显性矮秆基因Rht10亚染色体水平导入“中国春”的研究

Incorporation of the Dominant Dwarf Gene Rht10 into Common Wheat Variety“Chinese Spring”at the Subchromosomal Level

以 4 D染色体上携有 Ms2 -Rht1 0连锁基因的“矮败”小麦为模拟育种目的基因 Rht1 0的供体 ,以“中国春”为受体 ,通过中国春与矮败小麦的杂交、回交 ,利用同源染色体片段间“交换”的功能 ,解除 Rht1 0与Ms2 (太谷核不育基因 )的连锁 ,将 Rht1 0与其所在的一个染色体片段导入了中国春 4 D染色体相应的部位。测得 Rht1 0与 Ms2连锁解除时的交换值为 0 .1 2 % ,验证了 Rht1 0与 Ms2属紧密连锁的基因。 Rht1 0导入中国春后 ,最初获得的是株高为 72 cm左右的半矮秆可育的“初级目标植株”,以其自交及与中国春回交的后代所得的分离比例证实了 Rht1 0通过交换在初级目标植株中处于杂合状态。初级目标植株自交分离出了 Rht1 0纯合、株高为 2 9.3cm左右 (与“矮变 1号”株高相当 )的模拟育种的“目标植株”。Rht1 0导入中国春后所得的初级目标植株结实率较中国春原种显著降低 ,而目标植株则是雄性不育的 ,这表明 Rht1 0在中国春核遗传背景条件下对普通小麦的育性有明显的负面效应。由于 Ms2 Rht1 0连锁中的 Rht1 0基因可以在亚染色体水平上被操作 ,因此可以利用

Common wheat (Triticum aestivum L. ) var. “Aibai” carried the linked genes Ms2 and Rht10 on its chromosome 4D was used as the donor of the target gene Rht10, and var. “Chinese Spring” as the receptor in a simulated wheat breeding experiment. Through cross and backcross between the two varieties and with the help of interchange of autochromosome segments, the linkage between Rht10 and Ms2 (a sterility gene in Taigu) was successfully broken. A chromosome segment with Rht10 was incorporated into the corresponding location on chromosome 4D of Chinese Spring. Cross-over rate was 0.12% when the linkage between Rht10 and Ms2 was broken, verifying that the two genes were closely linked. After the incorporation of Rht10 into Chinese Spring, the “initial target plants” were semi-dwarf and fertile, with an average height of about 72 cm. Segregation ratio in the selfing and backcross progenies indicated that the initial target plants were heterozygous for Rht10. In the segregating selfing population, Rht10-homozygous plants were obtained, with an average height of 29.3 cm. Seed-setting of the initial target plants was significantly lower than that in the original cultivar Chinese Spring and the target plants behaved as male sterile. It showed that Rht10 had a substantial negative effect on the fertility of common wheat in the genetic background of Chinese Spring. Based on transfering Rht10 of the Ms2-Rht10 linkage group at the subchromosal level, a procedure for intragenerus breeding of Triticum with chromosomal engineering was recommended.