籼稻和粳稻是亚洲栽培稻的两个亚种，总体上粳稻品质性状明显优于籼稻。随着籼粳稻杂交育种的广泛应用，育成改良品种虽然含有亚种混合血缘，但是主要品质性状仍然存在显著籼粳差异，明确其生理生态与遗传机理，是本领域亟待研究的重要问题。课题组发现籼粳重组自交系及部分育成品种主要品质性状与籼粳属性并无直接关系，本项目在不同生态条件下种植籼粳重组自交系和分离世代群体(F2开始分别采用混合法、一粒传法和系谱法处理)，分别以程氏指数和籼粳特异分子标记作为群体形态分化和遗传分化的指标，研究生态条件对重组自交系品质的影响、与籼粳属性的关系，分离世代品质性状分化、形态分化、遗传分化规律及其相互关系，揭示自然与人工选择对品质性状分化的影响及其遗传基础，明确不同生态条件下影响籼粳交后代品质性状表现的主要环境因子，探索通过遗传改良充分发挥不同稻区品质生态优势的可能性与方法，为籼粳稻杂交优质高产育种提供科学依据。

Indica rice and japonica rice are the two subspecies of Asian cultivated rice,there are significant differences in the biological characteristics. The appearance and processing quality of japonica rice is significantly better than that of indica rice. The physiological ecology and genetic mechanism of this difference is an important issue to be studied. On the basis of found that it is unrelated between quality traits of recombinant inbred lines derived from the cross between indica rice and japonica rice and varieties bred and indica and japonica property in Liaoning, we plan to cultivate recombinant inbred lines andsegregating groups derived from the cross between indica rice and japonica rice under different ecological conditions (Guangdong in South China indica rice plant area, Sichuan in the Southwest China indica rice plant area, Shanghai in the Yangtze River indica and japonica rice overlapping plant area and Liaoning in northeastern japonica rice plant area. F2, respectively starting treated by mixing method, single seed descended method and pedigreemethod), apply Cheng's index and the indica and japonica specific molecular marker as indicators of morphological differentiation and genetic differentiation, study the effects of ecological conditions on the quality of recombinant inbred lines, and the relationship of the indica and japonica property, and the law of quality traits differentiation, morphological, genetic differentiation and their relationship of separating generation, reveal the effects of natural and artificial selection on differentiation of quality traits and its molecular genetic basis, make clear the key environmental factors that affect quality traits of offspring derived from the cross between indica rice and japonica rice under different ecological conditions, explore the possibilities and methods to give full play to the ecological advantage by the genetic improvement, provide a scientific basis for the high-yield and good quality breeding by indica and japonica rice hybrid.