Zhu Guanglong, Peng Shaobing, Huang Jianliang, Cui Kehui, Nie Lixiao, Wang Fei
National Key Laboratory of Crop Improvement, MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei Province 430070, China.
Sci Rep. 2016 Feb 15;6:21049. doi: 10.1038/srep21049.
The yield potential of rice (Oryza sativa L.) has experienced two significant growth periods that coincide with the introduction of semi-dwarfism and the utilization of heterosis. In present study, we determined the annual increase in the grain yield of rice varieties grown from 1936 to 2005 in Middle Reaches of Yangtze River and examined the contributions of RUE (radiation-use efficiency, the conversion efficiency of pre-anthesis intercepted global radiation to biomass) and NUE (nitrogen-use efficiency, the ratio of grain yield to aboveground N accumulation) to these improvements. An examination of the 70-year period showed that the annual gains of 61.9 and 75.3 kg ha(-1) in 2013 and 2014, respectively, corresponded to an annual increase of 1.18 and 1.16% in grain yields, respectively. The improvements in grain yield resulted from increases in the harvest index and biomass, and the sink size (spikelets per panicle) was significantly enlarged because of breeding for larger panicles. Improvements were observed in RUE and NUE through advancements in breeding. Moreover, both RUE and NUE were significantly correlated with the grain yield. Thus, our study suggests that genetic improvements in rice grain yield are associated with increased RUE and NUE.
水稻（Oryza sativa L.）的产量潜力经历了两个与半矮秆性状的引入和杂种优势的利用相吻合的显著增长期。在本研究中，我们测定了1936年至2005年长江中游种植的水稻品种的年籽粒产量增加情况，并研究了辐射利用效率（RUE，抽穗前截获的全球辐射转化为生物量的转化效率）和氮素利用效率（NUE，籽粒产量与地上部氮积累量的比值）对这些产量提高的贡献。对这70年的研究表明，2013年和2014年的年增产分别为61.9和75.3 kg ha-1，分别对应于籽粒产量年增长1.18%和1.16%。籽粒产量的提高源于收获指数和生物量的增加，并且由于培育出更大的穗，库容量（每穗小穗数）显著增大。通过育种进步，RUE和NUE均有所提高。此外，RUE和NUE均与籽粒产量显著相关。因此，我们的研究表明，水稻籽粒产量的遗传改良与RUE和NUE的提高有关。
