用SSR标记分析不同时期主要杂交水稻亲本的遗传差异变化

Perennial change of the genetic diversity between main parents in hybrid rice(Oryza sativa L.) as detected by SSR marker

本研究采用SSR标记技术分析了我国不同年代广泛应用的野败型杂交水稻9个恢复系和9个不育系的遗传差异。结果表明,(1)我国水稻亲本间的遗传差异较大,且在不育系与恢复系间>恢复系内>不育系内,较大的不育系与恢复系间的遗传差异是杂交水稻高产的原因;(2)与前期恢复系相比,虽然后期恢复系内的遗传差异没有显著增加,但选育出了以明恢63等为代表的遗传差异大的恢复系,这为20世纪80年代中、后期中国杂交水稻产量大幅度提高提供了基础;(3)不育系内的遗传差异后期并没有扩大,是20世纪90年代后中国杂交水稻产量徘徊不前的重要原因,增加不育系的遗传差异十分必要;(4)不同年代亲本的分子标记遗传差异变化与杂交水稻产量变化相关,分子标记揭示的遗传差异可为杂交育种中亲本的选择提供参考。

SSR technique was employed to detect genetic distances （GDs） among nine restorers and nine sterile lines, which were widely used in different years in the current work. The results demonstrated that there were relatively larger genetic differences among 18 parents, and tile GDs between sterile and restorer lines were larger than those among restorers as well as among sterile lines. The larger GDs between sterile and restorer lines considerably contributed to the high yield of hybrid flee. Compared to early - stage restorers, the GDs among late - stage ones were not improved, however, some restorers of larger GDs （ e. g. Minghui 63 ） Were created, which accounted for the high yield improvement of hybrid rice in the middle- to- late 1980s. In comparision with the early -stage sterile lines, the GDs were not improved among late - stage sterile lines, which was the important reason for little yield improvement of hybrid rice after 1990s. The GD changes based on SSR marker of main parents in different years were related to the yield trend of hybrid rice cultivars. Therefore, GDs based on molecular makers can be used as a reference in choosing parents in hybrid breeding.