我国籼型杂交水稻育种现状、问题与对策

Current Status and Strategy or Indica Hybrid Rice Breeding in China

本文是在全面总结“八五”期间我国三系杂交水稻育种工作的基础上，深入分析了籼型杂交水稻育种在产量上出现徘徊的原因，并针对在恢复系选育上存在的遗传组成基本相同，亲缘关系近，双亲遗传差异小等问题，提出了相应的技术对策。

During the Eighth Five一Year period,forty一five indica hybrid rice combinations,which cov-er various ecotypes,possess different maturity or have some specific characteristics,were examined provin-cially or nationally and released to farmers,and twelve new CMS lines with good flowering habits,high out-crossing rate and strong resistance passed the provincial or higher technical identifications,According to theresults of regional yield trials,all of these comibinations except Weiyou Wang 3 and Weiyou 77 showed onlya little yleld increase(less than 5%,not statistically different from standard combinations).The reasons areconsidered as:①most of the restorer lines of these combinations are derived from Ce64一7 and Minghui 63,resulting in a narrow genetic difference among them;②although the new CMS lines are greatly improved inthe aspects of resistance,grain quality of their hybrids,and the yield of hybrid seed production,they are notmuch better than the existing V20A and Zhenshan 97A in the aspect of yield heterosis of their hybrids. Inview of such problems,in the breeding of indica hybrid rice it is firstly required to choose various ecotype,different genetic origin and geographically distant resources as the crossing parents in breeding restorer linesand to break through the present situation of only using the IR derivatives. Secondly, the strong heterosis ofintersubspecif1c hybrids should be utilized by way of introducing some japonica genetic background into indi-ca restorer lines to widen the genetic difference between restorers and CMS lines and enrich the genetic foun-dations of the hybrids so as to increase the heterosis level.