Rice grain yield and quality responses to free-air CO2 enrichment combined with soil and water warming
Rice grain yield and quality responses to free-air CO2 enrichment combined with soil and water warming
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DOI：
10.1111/gcb.13128
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发表时间：
2016-03-01
影响因子：
11.6
通讯作者：
Hasegawa, Toshihiro
中科院分区：
文献类型：
--
作者：
Usui, Yasuhiro;Sakai, Hidemitsu;Hasegawa, Toshihiro
预计气温升高会降低水稻产量和质量，而大气CO2浓度（[CO2]）的增加可以增加谷物产量。对于灌溉水稻，积水是一个重要的温度环境，但很少有开放的领域的评价可用于温度和[CO2]的综合影响，这限制了我们的能力，以预测未来的水稻产量。我们进行了三个生长季节的自由空气CO2富集和土壤和水变暖实验，以确定产量和质量对升高[CO2]（+200molmol（-1），E-[CO2]）和土壤和水温（+2 ℃，E-T）的反应。E-[CO2]显著增加生物量和籽粒产量约14%，平均超过3a，主要是因为增加穗和小穗密度。E-T显著提高了生物量，但对籽粒产量影响不显著。E-T减少了从移栽到抽穗的天数约1%，但到最大分蘖数（MTN）阶段的天数减少了约8%，这限制了穗密度，因此库容量。另一方面，E-[CO2]使MTN阶段的天数增加了约4%，从而导致更多的分蘖。两种处理均降低了籽粒外观品质，但E-CO2处理的影响比E-T处理大得多。E-[CO2]显著降低未受损籽粒（UDG）的主要原因是白基粒（WBSG）比例增加，这与籽粒蛋白质含量呈负相关。一个显着降低籽粒蛋白质含量的E-[CO2]占WBSG增加的一部分。然而，WBSG对籽粒蛋白质含量的依赖性在不同年份之间是不同的;关系的斜率和截距与高于26摄氏度的热剂量呈正相关。稻米外观品质的年际变化表明，E-[CO2]和气温升高协同降低稻米外观品质。
Rising air temperatures are projected to reduce rice yield and quality, whereas increasing atmospheric CO2 concentrations ([CO2]) can increase grain yield. For irrigated rice, ponded water is an important temperature environment, but few open-field evaluations are available on the combined effects of temperature and [CO2], which limits our ability to predict future rice production. We conducted free-air CO2 enrichment and soil and water warming experiments, for three growing seasons to determine the yield and quality response to elevated [CO2] (+200molmol(-1), E-[CO2]) and soil and water temperatures (+2 degrees C, E-T). E-[CO2] significantly increased biomass and grain yield by approximately 14% averaged over 3years, mainly because of increased panicle and spikelet density. E-T significantly increased biomass but had no significant effect on the grain yield. E-T decreased days from transplanting to heading by approximately 1%, but days to the maximum tiller number (MTN) stage were reduced by approximately 8%, which limited the panicle density and therefore sink capacity. On the other hand, E-[CO2] increased days to the MTN stage by approximately 4%, leading to a greater number of tillers. Grain appearance quality was decreased by both treatments, but E-[CO2] showed a much larger effect than did E-T. The significant decrease in undamaged grains (UDG) by E-[CO2] was mainly the result of an increased percentage of white-base grains (WBSG), which were negatively correlated with grain protein content. A significant decrease in grain protein content by E-[CO2] accounted in part for the increased WBSG. The dependence of WBSG on grain protein content, however, was different among years; the slope and intercept of the relationship were positively correlated with a heat dose above 26 degrees C. Year-to-year variation in the response of grain appearance quality demonstrated that E-[CO2] and rising air temperatures synergistically reduce grain appearance quality of rice.