Abstract: In this study, 28 parents of crosses between indica and japonica rices were classified by Cheng's index. Results showed that the parents could be grouped into indica and japonica types. Among them most of the widely compatible lines were like to javanica. The F₁ hybrids with indica as female parent were largely indica type, accounting for 73.1% of the total, while those with japonica as female parent were largely japonica type, accounting for 72.4%. Among the F₁ of 92 crosses between indica and japonica the percentage of intermediate type was 73.9%, indicating that the nature of F₁ was determined by both the cytoplasm and the genetic background of parents. The difference in Cheng's index between the two parents was very significantly negatively correlated with the seed-setting rate in F₁ and very significantly positively correlated with the biological yield in F₁. If the difference value was adequate (6-13), higher seed-setting rate and biological yield, greater economic advantage would result in.

Key words: Cheng’s index, hybrid vigor, indica-japonica hybrid

摘要： 采用程氏指数分类法对籼粳交亲本及其F₁分类结果，28个亲本基本可分籼粳两大类，广亲和品种多属偏籼偏粳型，与爪哇型品种接近。以籼稻为母本的籼粳交F1籼型较多，约占73.1%， 以粳稻为母本的籼粳交F₁粳型较多，约占72.4%。92个籼粳交组合F₁偏籼、偏粳型比例为73.9%，这说明F₁分类既受细胞质影响，也受双亲遗传背景影响。双亲程氏指数差值与F₁结实率呈极显著的负相关，而与F₁的生物产量呈极显著正相关，双亲程氏指数差值大小适合(6-13)时， 生物产量与结实率均较高，其经济优势较强。

关键词: 程氏指教, 杂种优势, 籼粳亚种子一代