中国杂交籼稻品质改良现状分析

了解中国杂交籼稻品种的品质改良现状,对准确把握未来杂交水稻育种方向具有重要意义。分析了2001-2018年通过国家品种审定的971个(次)南方稻区杂交籼稻品种的整精米率、垩白粒率、垩白度、胶稠度和直链淀粉含量等5项主要品质性状指标。结果表明,"十五""十一五""十二五"和2016-2018年4个不同时期杂交籼稻优质率分别为22.4%、39.2%、36.1%和50.1%,优质化提升明显。18a来垩白粒率和垩白度的优质率提升最明显,分别由"十五"期间的37.1%和38.5%提升到2016-2018年间的81.9%和72.1%,但垩白粒率和垩白度的国优1级优质率仍然很低,2016-2018年间两系杂交籼稻分别仅为17.7%和6.0%,三系杂交籼稻分别仅为14.8%和8.2%,外观品质仍是杂交籼稻品质提升的瓶颈。杂交籼稻的"软米化"改良趋势明显,直链淀粉含量由"十五"期间的21.76%降低到2016-2018年间的16.52%。穗粒结构与品质性状存在显著相关性,大穗对提高整精米率、降低垩白粒率和垩白度有利,降低千粒重有利于全面改善稻米品质,尤其是提高整精米率,降低垩白粒率和垩白度。

Analysis on Grain Quality Improvement of Indica Hybrid Rice in China

To understand the quality status of indica hybrid rice in China and to highlight the focus for quality genetic improvement in the future, five quality traits(head rice rate, chalky rice rate, chalkiness, gel consistency and amylose content) of 971 southern indica hybrid rice varieties nationally-registered from 2001 to 2018 were analyzed. The results showed that the high-quality rate of varieties in four periods of 2001-2005, 2006-2010, 2011-2015 and 2016-2018 were 22.4%, 39.2%, 36.1% and 50.1%, respectively, indicating a significant quality improvement in the last 18 years. The improvement in chalky rice rate and chalkiness made the best progress with their high-quality rates increased from 37.1% and 38.5% in the period of 2001-2005 to 81.9% and 72.1% in the period of 2016-2018, respectively. However, the 1 st class high-quality rates of chalky rice rate and chalkiness were still low with only 17.7% and 6.0% for two-line indica hybrid rice varieties, 14.8% and 8.2% for three-line indica hybrid rice varieties, respectively, even in the period of 2016-2018, indicating that appearance grain quality would still be the emphasis of quality improvement for indica hybrid rice varieties. The amylose content improvement showed an obvious trend of "softy rice", with the average of amylose content dropped from 21.76% in 2001-2005 to 16.52% in 2016-2018. There exsited a significant correlation between panicle-grain structure and quality traits. Bigger panicle was advantageous to the improvement of head rice rate, chalky rice rate and chalkiness;and smaller grain was favorable to the quality improvement, especially for improvement of head rice rate, chalky rice rate and chalkiness.