Abstract: Rice quality variation was analyzed with two midseason rice combinations at different ecological sites, basic fertility of soil and nitrogen application levels in 2009. The results indicated that the genotype was the most important factor followed by the ecological conditions, the basic fertility of soil and the nitrogen application level. The interaction between the genotype and the experiment site had a significant or highly significant effect on the amylose content, the gel consistency, the percentage of head milled rice, the percentage of chalky rice and the chalkiness. The gel consistency was significantly affected by the interaction between the genotype and the nitrogen application level, and the interaction between the experimental site and the nitrogen application level had a significant effect on the percentage of head milled rice. Suitable environment conditions such as high altitude, low longitude,high available N, high available K in soil for Ⅱ you 7, and high altitude, high available N, low organic fertilizer, low total P in soil for Yuxiangyou 203 contributed to improve rice quality. The predict models were established respectively between the amylose, the gel consistency, the percentage of head milled rice, the chalkiness, the ratio length to width and the geographical position, the basic fertility of soil, the nitrogen application level for Ⅱ you 7  and Yuxiangyou 203.

Key words: midseason hybrid rice, rice quality variation, effect factor, predict model

摘要： 以杂交中稻高产组合Ⅱ优7号和高产优质新组合渝香优203为材料，在西南稻区4省（市）的6个生态点采用相同的试验方案，解析了稻米品质的影响因素。结果表明，基因型是影响稻米品质的最重要因素，环境条件（生态条件和土壤基础肥力）次之，施氮的作用最小。基因型与地点的互作显著或极显著影响直链淀粉含量、胶稠度、整精米率、垩白粒率、垩白度，基因型与施氮水平的互作仅显著影响胶稠度，地点与施肥水平的互作仅显著影响整精米率。Ⅱ优7号在高海拔、低经度、土壤高有效钾和高有效氮条件下，渝香优203在高海拔、土壤高有效氮、低有机质和低全磷条件下，米质较好。并分别建立了Ⅱ优7号和渝香优203稻米的直链淀粉、胶稠度、整精米率、垩白度、长宽比与地理位置、土壤基础肥力及施氮水平关系的预测模型。

关键词: 杂交中稻, 品质变异, 影响因素, 预测模型