摘要： 对61个组合的分析结果表明，两系杂交粳稻具有很强的优势，10个主要经济性状平均值均大于双亲平均值和大值亲本平均值，而且每穗总粒数、谷草比、每穗实粒数和单株谷重等性状具有较强的超亲优势和竞争优势；生育期、单株有效穗、结实率和千粒重等性状优势微弱，通径分析表明，对杂种一代单株谷重有显著影响的6个性状中，以每穗实粒数的作用最大，其它依次为单株有效穗谷草比、结实率、穗长和生育期。

关键词: 两系, 杂交粳稻, 杂种优势

Abstract: The heterosis of 61 two-line hybrids of rice were shown to be highly significant in ten agronomical characters.The average values of ten agronomic) characters in hybrids exceeded that of their parents and that of the parents with greater values.The transgressive heterosis and competitive heterosis were significant in such charaters as total grains per panicle,grain-to-straw ratio，filled grain number per panicle，grain weight per plant，while the heterosis of such characters, as the growth period duration，seeting percentage and weight of 1000-grains was weak.The results of path analysis indicated that among the 6 characters the filled grain number per plant showed the greatest effect on the grain weight per plant of Fl hybrids,and next to this characters the panicle number per plant, grain-to-straw ratio, seeting percentage, ear length and growth teriod duration showed more effect on it.

Key words: Two-line, Keng hybrid rice, Heterosis

中图分类号: 

• S511.22