Abstract:

To understand the grain quality of indica hybrid rice combinations in China and to clarify its key points for genetic improvement for the future, ten grain quality traits and their superior quality rates (SQRs) of 4495 indica hybrid rice combinations bred since 1984 were analyzed. The SQRs of the ten grain quality traits were from 34.2% to 97.9%, with an average of 78.5%. The excellent indica hybrid rice combinations with all the five key grain quality traits (head rice rate, chalkiness degree, transparency degree, amylose content and quality index) in or above the standards of the third class superior quality of rice occupied 29.9% of the total. The average SQRs for the ten grain quality traits of the tested combinations bred in the three periods, 1980s, 1990s and 2001-2008, were 64.2%, 71.1% and 81.4%, and the SQRs for quality indices were 84.5%, 86.4% and 88.5%, respectively. The excellent indica hybrid rice combinations bred in 2001-2008 with all of the five key quality traits in or above the standards of the third class superior quality occupied 32.9%, 18.0 and 11.9 percent points higher than that in 1980s and 1990s. The above results indicated that in general, the grain quality of the indica hybrid rice combinations bred in 2001-2008 was better than that in 1980s and 1990s. The tested combinations of Boyou-, Zhongyou- and Peiyou-series showed better grain quality. On the other hand, it was noticed that the SQRs of chalky grain rate and chalkiness degree were rather lower (only 34.2% and 55.1%, respectively) than that of other eight quality traits，which would be the emphasis of grain quality improvement of indica hybrid rice in recent future.

Key words: indica hybrid rice, rice grain quality, superior quality rate, quality improvement

摘要：

为了解我国近25年来育成的杂交籼稻组合的米质状况和未来品质改良重点，分析了我国自1984年以来育成的4495份杂交籼稻组合的10项米质指标及其优质达标率。结果表明，检测的4495份杂交籼稻材料10项米质性状的优质达标率为34.2%～98.1%，平均78.5%。5项主要米质指标（整精米率、垩白度、透明度、直链淀粉含量和质量指数）全部达到优质标准的材料占29.9%。20世纪80年代、90年代和2001-2008年3个不同时期育成的杂交籼稻组合10项米质性状的平均优质达标率分别为64.2%、71.1%和81.4%，质量指数优质达标率分别为84.5%、86.4%和88.5%。2001-2008年期间育成的杂交籼稻材料5项主要米质指标全部达到优质标准的占32.9%，比20世纪80年代和90年代的分别高18.0和11.9个百分点，表明2001-2008年育成的杂交籼稻组合的米质总体优于20世纪80年代和90年代育成的组合。博优、中优和培优系列组合的米质较好。分析同时指出，我国杂交籼稻组合的垩白粒率和垩白度的优质达标率较低，仅34.2%和55.1%，是未来杂交籼稻米质改良的重点。

关键词: 杂交籼稻, 米质, 优质达标率