Abstract: In pot experiment, the comparative study on the flowering and filling characteristics of inter-subspecific rice hybrid Xieyou 413, its restorer line Zhong 413 and indica rice hybrid Shanyou 10 was conducted. The results showed Zhong 413, Xieyou 413 and Shanyou 10 were the highest, second and the lowest respectively in total grain dry matter per panicle. Seed setting rate for Zhong 413 and Xieyou 413 was nearly the same, 80.8% and 83.9% respectively, which was significantly higher than Shanyou 10(70.5% ). Under the circumstances, the difference of productivity of various rice hybrid crosses and the restorer line was mainly related to their flowering and filling characteristics,i.e. the concentration of floret flowering for a panicle and the filling difference of superior grains on top part of the panicle and proximal inferior grains. The more concentrative the floret flowering for the panicle is, the less the difference of filling and ripening for superior and inferior grains is, the higher the yield for a panicle. In the paper, the short flowering duration for a panicle used as the breeding goal for inter-subspecific rice hybrids is also discussed.

Key words: flowering and filling, inferior grains, inter-subspecific rice hybrid, superior grains, seed setting

摘要： 以盆栽试验对亚种间杂交水稻协优413、其父本中413和籼型杂交水稻汕优10号的开花灌浆特性进行了比较研究。结果表明中413单穗籽粒总干物重最高，协优413次之，汕优10号最低，分别为4652.5、4173.9和3194.4 mg，结实率中413和协优413相近，分别为80.8%和83.9%，显著高于汕优10号的70.5%。单穗产量的差异与组合(恢复系)的开花灌浆特性有关，即与单穗颖花开花集中程度和强弱势粒灌浆结实的差异程度有关。对于供试的3个品种(或组合)而言，颖花开花越集中，强弱势粒灌浆结实差异越小，产量越高。还对单穗颖花开花历时作为今后亚种间杂交水稻的育种目标进行了讨论。

关键词: 亚种间杂交水稻, 开花和灌浆, 结实率, 强势粒, 弱势粒