Abstract: The grain quality traits and their relationships of 86 medium amylose content hybrid rice combinations were studied and analyzed in Sichuan Province. The results showed that the quality traits are quite different. The difference in chalkiness degree was the biggest, CV was 33.22%; followed by chalky rice rate, CV was 23.32%; the last was brown rice rate, CV was 1.01%. According to the high quality rice standards of individual traits, except the amylose content, the high compliance rate are gel consistency and head milled rice rate, there are 94.19% and 86.05% combinations up to three grade quality rice; the low compliance rate are chalky rice rate and chalkiness degree, there are only 3.49% and 4.65% combinations up to three grade quality rice. Comprehensive quality indexes of 2 combinations reach three grade quality standards in the 86 indica hybrid rice combinations. Correlation analysis results showed that in medium amylose content（15%~24%）, amylose content is highly significant positive correlation with chalky rice rate and chalkiness degree; gel consistency is highly significant negative correlation with protein content; chalkiness degree is highly significant negative correlation with length-width ratio, and highly significant positive correlation with chalky rice rate; length-width ratio is highly significant negative correlation with head rice rate and chalky rice rate. It is main target to ruduce the chalky rice rate and chalkiness degree and then pay attention to the selection of strong resistant to rice milling in rice quality improvement.

Key words:  indica hybrid rice, medium amylose content: quality character, correlation analysis

摘要： 对2012年四川省水稻区试的86个中等直链淀粉含量籼型杂交稻组合的主要品质性状及相关性进行了研究分析。结果表明，86个组合的品质性状中差异最大的是垩白度，变异系数为33.22%；其次是垩白粒率，变异系数为23.32%；差异最小的是糙米率，变异系数为1.01%。按优质稻米标准衡量单个品质性状，除直链淀粉含量外，达标率较高的是胶稠度和整精米率，达3级优质米以上标准的品种比例为94.19%和86.05%；达标率较低的是垩白粒率和垩白度，达3级优质米的品种比例仅为3.49%和4.65%。在86个组合中仅有2个组合综合品质性状指标达3级优质米标准。相关分析结果表明，在中等直链淀粉含量（15%～24%）范围内，直链淀粉含量与垩白粒率、垩白度极显著正相关；胶稠度与蛋白质含量极显著负相关；垩白度与长宽比极显著负相关，与蛋白质含量显著负相关，与垩白粒率极显著正相关；长宽比与整精米率、垩白粒率极显著负相关。在改良稻米品质的选择上必须以降低垩白粒率和垩白度为主攻目标，并注意耐碾磨力强的粒型选择。

关键词: 籼型杂交稻, 中等直链淀粉含量, 品质性状, 相关分析