The responses of rice ( L.) yield and quality to the combination of elevated CO and elevated temperature under open-air field conditions are still poorly understood. A japonica rice cultivar Wuyungeng 23 was grown under four combination of two levels of CO (ambient and enriched up to 590 μmol mol) and two levels of canopy temperature (ambient and warmed by 1.7–2.2 ºC during both night-time and day-time or during only day-time) in T-FACE (temperature by free-air CO enrichment) systems over two years. Our results showed that grain yield was decreased by 15.1% under the combination of elevated CO and elevated both night-time and day-time temperature, but increased by 3.5% under the combination of elevated CO and elevated only day-time temperature. Among yield components, panicle number, spikelet fertility and single grain weight significantly contributed to yield variations under the four CO and temperature treatments over two years. Interannual variations in these three yield components were associated with large interannual variations in air temperature after flowering and in solar radiation before flowering under ambient conditions. Among grain quality traits, chalky grain percentage and chalkiness degree also showed large interannual variations under the four CO and temperature treatments. Both chalky grain percentage and chalkiness degree increased with a decrease in grain yield under elevated CO and elevated temperature across years. Our study suggests that both grain yield and grain quality of rice need to be sustained under future climate change.

中文翻译：

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T-FACE 环境中水稻籽粒产量和品质对环境和升高的 CO2 和温度因子组合的响应

在露天田间条件下，水稻产量和品质对 CO 升高和温度升高的响应仍知之甚少。粳稻品种武云耕 23 在两种 CO 水平（环境和富集至 590 μmol mol）和两种冠层温度（环境和夜间和白天升温 1.7-2.2 ℃）的四种组合下生长或仅在白天）在 T-FACE（自由空气 CO 浓缩温度）系统中运行两年。结果表明，CO2升高与夜间和白天温度同时升高的组合下，粮食产量下降了15.1%，而CO2升高和仅白天温度升高的组合下，粮食产量增加了3.5%。在产量构成中，穗数、小穗育性和单粒重对两年内四种二氧化碳和温度处理下的产量变化有显着影响。这三个产量组成部分的年际变化与环境条件下开花后气温和开花前太阳辐射的较大年际变化有关。籽粒品质性状中，垩白粒率和垩白度在四种CO和温度处理下也表现出较大的年际变化。多年来，随着二氧化碳浓度升高和温度升高，谷物产量下降，垩白谷物百分比和垩白程度均增加。我们的研究表明，在未来的气候变化下，水稻的产量和品质都需要保持不变。