Abstract: In 2006-2007, the F8 (92 lines) and F9 (142 lines) generations of the recombinant inbred lines (RILs) populations derived from a cross between Qishanzhan (indica cultivar) and Akihikari (japonica cultivar) were used to investigate the Cheng′s index (ChI) and performance of indica/japonica diagnostic SSR markers (Dj value), and 11 rice quality traits. In the study, ChI was used to represent morphological differentiation (ChI<14, indica type; ChI≥14, japonica type) and Dj value was to display genetic differentiation, which is number of SSR loci identical to those of Akihikari divided by total number of SSR loci identical to Akihikari and Qishanzhan (Dj<50, indica type; ChI≥50, japonica type). Both F8 and F9 populations showed a normal distribution in the ChI and Dj values. The number of lines with indica type was similar to those with japonica type based on the ChI values, whereas an obvious japonicainclined distribution was found based on the Dj values in the two populations. There was no significant difference in most rice quality traits except milled rice width between indica and japonica types classified by the ChI values. Based on the Dj values, the two RILs populations could be divided into japonicalinous type (Dj<75) and japonica type (Dj≥75). The japonica type showed significantly higher brown rice rate, milled rice rate and milled rice width, and significantly lower ratio of milled rice length to width than the japonicalinous type. The Cheng′s index had no significant relationship with all the rice quality traits in the two generations. The Dj value had significantly positive correlations with brown rice rate, milled rice rate and milled rice width, and significantly negative correlation with the ratio of milled rice length to width. It is suggested that there was no significant correlation between the morphological differentiation and rice quality traits in japonica rice in northern China, and the milled rice quality could be improved through increasing japonica component in genetic differentiation.

Key words: rice, quality, simple sequence repeat marker, Cheng′s index, indica and japonica differentiation

摘要： 2006—2007年以典型籼稻七山占和典型粳稻秋光构建的重组自交系（RILs） F8 的92个株系和F9 的142个株系为试材，分别以程氏指数（ChI）和籼粳特异SSR标记（Dj）为群体形态分化与遗传分化的指标，同时测定11项主要稻米品质性状，分析群体稻米品质性状类型间差异及籼粳属性与稻米品质性状的相关性。结果表明，两世代RILs群体形态分化均表现为接近正态的连续分布，籼型和粳型株系数接近，遗传分化则均表现为明显偏粳的连续分布；根据ChI将RILs群体划分为籼型和粳型，除F9粒宽外两世代品质性状类型间差异均未达到显著水平；根据Dj将RILs群体划分为偏粳型和粳型，两世代粳型糙米率、整精米率、粒宽显著或极显著高于偏粳型，长宽比极显著低于偏粳型；两世代RILs群体ChI与所有品质性状的相关性均未达到显著水平; Dj与糙米率、整精米率和粒宽呈显著或极显著正相关，而与长宽比呈显著或极显著负相关。形态分化与北方粳稻品质性状没有直接关系，而遗传分化中粳稻血缘比例增加可能通过粒形间接改善碾磨品质。

关键词: 水稻, 品质, 微卫星标记, 程氏指数, 籼粳属性