大气CO_2浓度和温度升高对超级稻生长发育的影响

Impact of elevated atmospheric CO_2 concentration and temperature on growth and development of super rice

利用稻田FACE（Free Air gas Concentration Enrichment）系统，设置对照（Ambient, 环境空气）、CO2浓度增高（EC，比Ambient增200 μmol·mol-1）、温度增高（ET，比Ambient增2 ℃）和CO2浓度与温度同步增高（EC＋ET）4个处理，研究其对超级杂交籼稻Ⅱ优084生长发育的影响。结果表明：与Ambient相比，EC或EC＋ET使水稻抽穗和成熟期推迟1～3 d，但ET对生育期没有影响；EC、EC＋ET使水稻成熟期单茎干重分别增加49%、40%，均达显著水平，但ET则呈相反趋势；与Ambient相比，EC使成熟期叶片、茎鞘、稻穗及地上部干重分别增加40%、69%、30%和39%，均达极显著水平；ET使对应部位干重分别减少11%、21%、31%和26%，除茎鞘外均达显著或极显著水平；EC＋ET使对应部位干重分别增加40%、47%、10%和18%，除稻穗外均达显著水平；抽穗期和抽穗后20 d各器官干重及地上部总重对各处理的响应趋势一致，但幅度明显小于成熟期；与生物量不同，各处理对结实期物质分配比例影响较小；EC、EC＋ET使水稻成熟期茎鞘非结构性碳水化合物浓度和含量显著增加，但ET表现出相反趋势。综上所述，大气CO2浓度和温度同时升高情形下，超级稻Ⅱ优084收获期茎鞘同化物浓度和含量、各器官干重以及地上部生长总量均明显增加，但增幅略小于单独CO2浓度升高环境下生长的水稻。

Using Chinese FACE （Free Air gas Concentration Enrichment） facility, we conducted a field experiment to investigate the impacts of ambient air （Ambient）, elevated ／[CO2／] （EC, Ambient＋200 μmol·mol-1）, elevated temperature （ET, Ambient＋2 ℃） and elevated ／[CO2／]＋elevated temperature （EC＋ET） on growth and development of a super rice cultivar ⅡY084. The results showed that the heading and maturity stage arrived 1-3 days later in EC and EC＋ET treatments than in Ambient, but no response was detected in ET treatment. Compared with Ambient, EC and EC＋ET treatments significantly increased the final dry weight per stem by 49% and 40%, respectively, but ET treatment showed the opposite tendency. On average, leaf, stem and sheath, panicle and aboveground biomass at maturity increased under EC by 40% （P〈0.01）, 69% （P〈0.01）, 30% （P〈0.01）, and 39% （P〈0.01）, but decreased under ET by 11% （P〈0.05）, 21% （P=0.14）, 31% （P〈0.01） and 26% （P〈0.01）, respectively. The respective increase due to EC＋ET treatment was 40% （P〈0.05）, 47% （P〈0.05）, 10% （P=0.33） and 18% （P〈0.05）, respectively. In general, aboveground biomass and its components at heading and 20 days after heading showed a similar pattern, with the magnitude of responses being less than those at maturity. In contrast to biomass production, less effect of CO2 or temperature treatment was found on dry matter allocation in plants. EC and EC＋ET treatments significantly increased the concentration and content of nonstructural carbohydrates （NSC） in stem and sheath at the maturity stage, but ET showed the opposite trend. The above results indicated that, as for super rice ⅡY084, the combination of elevated CO2 concentration and temperature in the near future would result in increases in the concentration and content of NSC in stem and sheath, total biomass production and its components at harvest time, but the magnitudes of the increases are less than those by elevated CO2 concentration alone.