两份玉米CMS-C恢复系的育性恢复力测定及恢复基因的分子标记定位

为了发掘更多玉米C型不育胞质的强恢复系资源,本研究对2份自交系Z16和7250-14-1进行了恢复能力的测定、恢复基因的遗传分析及恢复基因的分子标记定位。结果表明, Z16和7250-14-1对C黄早四、C478、C698-3和CMo17均表现为育性恢复,而对C48-2则均表现为育性部分恢复。通过对玉米CMS-C不同亚组胞质测交鉴定发现, Z16对G48-2、EC48-2、ES48-2、RB48-2及类48-2均表现为不育性保持,而7250-14-1对G48-2、EC48-2、ES48-2表现为育性部分恢复,对RB48-2和类48-2则表现为不育性保持。Z16和7250-14-1对CMS-T不育系均表现为不育性保持,而对CMS-S不育系则均表现为育性部分恢复。遗传分析显示, Z16对C478和C黄早四的育性恢复均受1对基因控制;而7250-14-1对C黄早四及C478的育性恢复分别受1对基因及2对基因控制。利用(C黄早四×Z16)F2、(C黄早四×7250-14-1)F2群体分别对恢复基因进行分子标记定位,其中Z16的恢复基因被定位于标记B-1至第8染色体短臂末端区域,物理距离为494 kb; 7250-14-1的恢复基因被定位于第8染色体短臂的标记B-1和Chr8-86080之间,物理距离为249kb。该研究不仅为玉米CMS-C"三系"配套的生产利用提供了恢复基因资源,也为玉米CMS-C恢复基因的克隆及恢复机制的研究奠定了一定基础。

Identification of fertility restoration and molecular mapping of restorer genes in two maize restore lines of CMS-C

The objective of the present study was to identify novel and powerful restorer lines for CMS-C. So maize inbred lines Z16 and 7250-14-1 were crossed with both isonuclear alloplasmic and isoplasmic allonuclear CMS-C, CMS-T, and CMS-S male sterile lines. Self-cross and back-cross were conducted for some of the fertility restored F₁ for genetic analysis and restorer gene mapping. Male fertility expression was investigated for all the F₁, F₂ and backcross populations, showing that Z16 and 7250-14-1 could restore the fertility for C Huangzaosi, C478, C698-3, and CMo17 completely, and partly restore the fertility for C48-2. Z16 could not restore the fertility for G48-2, EC48-2, ES48-2, RB48-2, and Lei48-2, while 7250-14-1 could partly restore the fertility for G48-2, EC48-2, and ES48-2, and maintain the sterility for RB48-2 and Lei48-2. Both Z16 and 7250-14-1 couldn’t restore the fertility of CMS-T, and partly restore the fertility for CMS-S. Genetic analysis showed that the fertility restoration was controlled by a pair of dominant genes for Z16 when crossed with C478 or C Huangzaosi. But for 7250-14-1, the fertility restoration was controlled by a pair of dominant genes for C Huangzaosi, and two pairs of complementary dominant genes for C478. Both of the restorer genes for Z16 and 7250-14-1 were mapped on the short arm of chromosome 8 by molecular markers. For Z16, it was mapped within a physical distance of 494 kb from the marker B-1 to the end of the chromosome, and for 7250-14-1, it was located between B-1 and Chr8-86080, with physical distance of 249 kb. This study not only provides some information for the practical application of Z16 and 7250-14-1, but also lays a foundation for the cloning and functional analysis of restorer genes.