Abstract: Based on total 8 390 rice samples of indica conventional rice, indica hybrid rice, japonica conventional rice, japonica hybrid rice, the differences of the quality traits among different rice types were analyzed. The main results were as follows: (1) Variation coefficients of quality traits in conventional rice varieties were slightly higher than those of hybrid rice. Variation coefficients of grain chalkiness, translucency and chalkiness were high, but those of brown rice rate, milled rice rate and head rice rate were low. (2)Quality of japonica rice was higher than that of indica. Chalkiness, head rice rate and amylose content should be emphasized in indica rice quality improvement. Reducing chalky grain and increasing head rice rate were important in japonica rice quality improvement. (3) The quality of indica hybrid rice was improved significantly. Except chalkiness, frequency of the other quality characteristics meeting the high quality standards was high. (4) In indica conventional rice, the frequency of chalkiness and amylose content appeared two apex distribution, both high quality and low quality indica conventional rice rate were high.

Key words: rice, quality, variation

摘要： 对来自全国各地的8 390份稻米样品按籼型常规稻、籼型杂交稻、粳型常规稻和粳型杂交稻进行分类，并对其品质性状做了比较分析。结果表明：（1）常规稻品质性状的变异系数略高于杂交稻。糙米率、精米率、粒长和长宽比的变异系数较小，垩白米率、透明度和垩白度的变异系数较大。（2）粳稻的品质优于籼稻。垩白、整精米率和直链淀粉含量是籼稻品质改良的重点，垩白和整精米率是粳稻品质改良的重点。（3）籼型杂交稻的稻米品质得到明显改善，除垩白外，其他品质性状达到优质米一、二级标准的比率均较高。（4）籼型常规稻的垩白和直链淀粉含量呈两极分布，籼型常规稻中米质较优和较差的样品比例均较高。

关键词: 稻米, 品质, 变异