宁夏水稻粒形变化对品质的影响

对33份宁夏粳稻品种（系）粒形与各品质性状间的关系进行分析表明，随米粒长宽比增加，垩白米率和垩白度均呈显著下降趋势，糙米率和精米率呈降低趋势，而整精米率则表现为单峰曲线趋势，即米粒长宽比为2.00~2.19时整精米率最高，蒸煮和营养品质表现为脂肪含量显著增加（P<0.01），而胶稠度、蛋白质含量和直链淀粉含量无显著变化。相关性分析表明，米粒长宽比与垩白粒率和垩白度呈极显著负相关，与糙米率、胶稠度和直链淀粉含量呈显著负相关，与脂肪含量呈显著正相关。表明粳稻米粒长宽比增加，可显著改变大米的外观品质，粒形与一些碾磨、蒸煮、营养品质因子具显著相关性。

Effect of Grain Shape on the Quality of Oryza sativa subsp.japonica Rice in Ningxia

33 Oryza sativa subsp. japonica rice varieties (lines) from Ningxia were used as materials to analyze the relation of grain shape to rice quality in this paper. The result showed that, with the increase of grain length/width ratio, the chalky rice rate and chalkiness degree had a significant downward trend, the brown rice rate and the milled rice rate were decreased too, while the whole milled rice rate performed as a single peak curve trend with the highest value when grain length/width ratio ranged from 2.00 to 2.19. The fat content increased significantly (P<0.01), whereas no significant changed in gel consistency, protein content and amylose content with the grain shape increasing. The grain length/width ratio was significant negative correlation with the chalky rice rate and chalkiness degree, and significant negative correlation with the brown rice rate, gel consistency and amylose content showed, while significant positive correlation with fat content. In our studies, the appearance quality of rice changed with rice grain shape (grain length/width ratio), and rice grain shape were significant correlation with milling, cooking, nutrition and quality factors. The grain length/width ratio ranging from 2.00 to 2.19 is appropriate threshold of grain shape for Ningxia rice quality breeding.