水稻雄性不育细胞质对杂交早稻产量性状的影响

利用Ｋ型、Ｄ型等七种不同的雄性不育细胞质的同核异质不育系及其保持系分别与两个早熟恢复系杂交，研究胞质对杂种一代单株稻谷产量、穗长、每穗总粒数、每穗实粒数、每穗秕粒数、结实率和千粒重的影响，结果表明不同胞质对这些性状的影响存在明显差异，同一胞质对不同性状的影响程度也不同。多数胞质都有使这些性状变劣的效应，但Ｋ型和Ｄ型两种胞质对单株产量和每穗总粒数均不表现负效应，对其他性状的变劣效应也较小。并探明了杂交早稻结实率低的原因是雄性不育细胞质的负效应。可以通过筛选和利用优良胞质来减小或消除胞质负效应。

EFFECTS OF CYTOPLASMIC MALE STERILITY(CMS)ON THE YIELD TRAITS OF EARLY-SEASON HYBRID RICE

Studies were conducted on the effects of seven male sterile cytoplasms(CMS),KA,JA,LA(three kinds of CMS from our breeding materials),DA(from D shan A),WA(from Zhen Shan 97 A), SA(from XieQing Zao A), and YA(from Ⅱ-32A), on seven yield traits including grain yield per plant,panicle length,total spikelet number per panicle,filled spikelet number per panicle,unfilled spikelet number per panicle,filled spikelet percentage and 1000-grain weight of early-season hybrid rice. The results showed that different CMSs produced different effects on these traits,with different effects on different traits by even same CMS,and most of the CMSs had negative effects. Hwever, KA and DA showed a little positive effect on grain yield per plant and total spikelet number per panicle with lower negative effects on the other characters comparison with other CMSs. Te reason of low filled spikelet percentage for early-season hybrid rice was manifested,e.g. the high significant negative effect os CMSon the trait. Nvertheless, the negative effects of CMScould be decreased to no significant level by selecting and utilizing elite CMS in early-season hybrid rice breeding programme.