Feng Fan, Li Yajun, Qin Xiaoliang, Liao Yuncheng, Siddique Kadambot H M
College of Agronomy, Northwest A&F University, Yangling, China.
The UWA Institute of Agriculture, School of Agriculture and Environment, The University of Western Australia, Perth, WA, Australia.
Front Plant Sci. 2017 Oct 31;8:1863. doi: 10.3389/fpls.2017.01863. eCollection 2017.
China is the first country to use heterosis successfully for commercial rice production. This study compared the main quality characteristics (head rice rate, chalky rice rate, chalkiness degree, gel consistency, amylose content, and length-to-width ratio) of 635 rice varieties (not including upland and glutinous rice) released from 2000 to 2014 to establish the quality status and offer suggestions for future rice breeding for grain quality in China. In the past 15 years, grain quality in japonica rice and indica hybrid rice has improved. In japonica rice, inbred varieties have increased head rice rates and decreased chalkiness degree over time, while hybrid rice varieties have decreased chalky rice rates and chalkiness degree. In indica hybrid rice, the chalkiness degree and amylose contents have decreased and gel consistency has increased. Improvements in grain quality in indica inbred rice have been limited, with some increases in head rice rate and decreases in chalky rice rate and amylose content. From 2010 to 2014, the percentage of indica varieties meeting the Grade III national standard of rice quality for different quality traits was low, especially for chalky rice rate and chalkiness degree. Japonica varieties have more superior grain quality than indica rice in terms of higher head rice rates and gel consistency, lower chalky rice rates and chalkiness degree, and lower amylose contents, which may explain why the Chinese prefer japonica rice. The japonica rice varieties, both hybrid and inbred, had similar grain qualities, but this varied in indica rice with the hybrid varieties having higher grain quality than inbred varieties due to significantly better head rice rates and lower chalkiness degree. For better quality rice in future, the chalky rice rate and chalkiness degree should be improved in japonica rice along with most of the quality traits in indica rice.
中国是首个成功将杂种优势用于商业水稻生产的国家。本研究比较了2000年至2014年间发布的635个水稻品种（不包括旱稻和糯米）的主要品质特性（整精米率、垩白米率、垩白度、胶稠度、直链淀粉含量和长宽比），以确定品质状况，并为中国未来水稻品质育种提供建议。在过去15年中，粳稻和籼型杂交水稻的品质有所改善。在粳稻中，随着时间的推移，常规品种的整精米率提高，垩白度降低，而杂交水稻品种的垩白米率和垩白度降低。在籼型杂交水稻中，垩白度和直链淀粉含量降低，胶稠度增加。籼稻常规品种的品质改善有限，整精米率有所提高，垩白米率和直链淀粉含量有所降低。2010年至2014年，不同品质性状达到国家三级优质米标准的籼稻品种比例较低，尤其是垩白米率和垩白度。在整精米率和胶稠度较高、垩白米率和垩白度较低、直链淀粉含量较低方面，粳稻品种的品质优于籼稻，这或许可以解释为什么中国人更喜欢粳稻。粳稻的杂交品种和常规品种品质相似，但籼稻则不同，杂交品种的品质高于常规品种，因为其整精米率明显更高，垩白度更低。为了未来培育出品质更好的水稻，粳稻应提高垩白米率和垩白度，籼稻则应改善大部分品质性状。
