CO_2浓度和温度升高对早稻生长及产量的影响

Influence of Elevated Atmospheric CO_2 Concentration and Temperature on Growth and Yield of Early Rice

研究温度升高和CO2浓度增加的气候变化条件对我国主要粮食作物早稻生长及产量的影响对评估国家粮食安全有重要参考意义。采用改进后的开顶式气室原位模拟大气CO2浓度450μL·L^-1及温度升高2℃的环境条件对早稻生长及产量的影响,试验设置三个处理（对照、增温、增温＋CO2）,结果表明：①温度及CO2同增对早稻最终株高有显著增加作用,而仅增温只能加快前期株高增长速度而对最终株高没有影响;②增温处理使最终分蘖数增加2～3茎·穴^-1,但在增温条件下增加CO2浓度,分蘖数不再增加;③增加CO2浓度使早稻叶片叶绿素含量略增,但增温处理没有效应;④增温处理对不同时期地上部生物量无显著影响,但增温＋CO2处理使各期生物量较对照显著增加;⑤增温2℃使早稻增产13.3%,而增温基础上再增CO2,产量不再进一步增加。从产量构成因子看,增温或增温＋CO2处理条件下早稻增产主要与穗数和每穗粒数增加有关。

It is very important for national cereal security evaluation to study the influence of elevated CO2 concentration and temperature on early rice growth and yield under changed climate scenario. We studied the effects of 450 μL·L^-1 CO2 concentration and 2 ℃ temperature increments on early rice growth and yield in an early rice field using a modified open-top chamber method. There were 3 treatments with 3replication per treatment：①Check OTC（ambient atmospheric CO2 and temperature）, ②air temperature increase by 2 ℃, and ③air temperature increase by 2 ℃ plus 60 μL·L^-1CO2 elevation. Treatment with both CO2 concentration and temperature rise significantly increased the final height of early rice, while temperature alone expedited plant elongation speed only without showing effects on the final height of early rice. Elevated temperature increased the number of tiller of early rice by 2～3 tillers per hole, but CO2 had no obvious effects on the number of tiller of early rice. Increasing CO2 concentration had a positive effect on leaf chlorophyll content, but increasing temperature did not. The aboveground biomass of early rice was not influenced by temperature rise, but increased significantly by temperature plus CO2 concentration.Grain yield of early rice was increased by 13.3% by temperature rise, but was no additional increase by elevated CO2. Temperature influenced yields via increasing spike rates and grains per spike.