Abstract: Heterosis of eight agronomic important characters of F₁ derived from different ecological types in japonica rice and combining ability of their parents were studied by an 8×8 diallel design. Results indicated that both positive and negative heterosis existed in all the 8 characters. On the average of 56 F₁ combinations, grain yield per plot showed 19.5% heterosis over high parents, 87.5% of the combinations showed higher grain yield per plot than that of the high parents, and for the other 7 characters, F₁ values were between mid parent and high parent. In the populations consisted of different ecological types of japonica rice, additive and non additive genetic effects were equally important for the four characters of plant height, spikelets per panicle, filled grains per panicle and grain yield per plot. For the three characters of heading date, panicle length and effective panicles per plant, additive effects were more important than those of non additive. And for the character of 1000 grain weight, non additive effect was more important than that of additive. Xiushui 04 and 3726 were the parents with excellent general combining ability effects and special combining ability variance for grain yield per plot and yield components. Koshihikari/Xiushui 04 was a superior combination with good special combining ability effects and overall characters.

Key words: rice, ecological type, heterosis, combining ability, agronomic characteristics

摘要： 用8个不同生态类型的粳稻品种配成8×8双列杂交，研究8个重要农艺性状的杂种优势以及亲本的配合力。结果表明，不同生态类型间杂种F1 各性状的优势有正有负。56个F1组合平均, 小区产量性状表现19.5%的高亲优势, F1小区产量超过高亲值的组合占87.5%，其余7个性状的F1值位于中亲值与高亲值之间。 在不同生态类型所构成的总体中，株高、每穗总粒数、每穗实粒数和小区产量4个性状的加性遗传方差和非加性遗传方差同等重要；抽穗期、穗长、单株有效穗3个性状的加性遗传方差更重要；千粒重性状非加性遗传方差更为重要。小区产量和产量构成因素一般配合力效应和特殊配合力效应方差较大的亲本是秀水04和3726；特殊配合力效应大且综合性状优良的组合是越光/秀水04。

关键词: 粳稻, 生态类型, 杂种优势, 配合力, 农艺性状