CO2浓度升高对春小麦光合作用和籽粒产量的影响

Effects of CO_2 Enrichment on Photosynthesis and Grain Yield of Spring Wheat

为给在大气CO2浓度升高条件下农作物栽培和农业可持续发展的科学管理决策提供依据,利用开顶式气室(OTC)研究了大气CO2浓度升高对春小麦辽春15生长发育过程中净光合速率、田间气体交换特性、光合酶活性等光合生理生态指标的变化规律以及对籽粒产量的影响。结果表明,CO2浓度增加到550μmol.mol-1条件下,小麦叶片Pn升高,在孕穗期、灌浆期增幅达到显著水平(P<0.05);叶片Ci提高,在灌浆期Ci增加达到极显著的水平(P<0.01);而小麦叶片Gs、Tr呈下降趋势,均在灌浆期与CK差异显著(P<0.05);各生育时期小麦叶片Hill反应活力都增强,孕穗期升高达到显著水平(P<0.05);叶绿体Ca2+/Mg2+-ATPase活性均高于对照,但未达到显著水平。高CO2浓度使得小麦生物量积累有所增加,在拔节期、孕穗期小麦植株干重极显著增加(P<0.01);提高了小麦籽粒产量,表现为穗粒重极显著增加(P<0.01)。在光合作用的整个过程中CO2浓度升高都起到了促进作用,并且最终表现在植株生物量和籽粒产量上。

Changes of net photosynthetic rate,gas exchange characteristics and relevant photosynthetic enzyme activity and biomass of wheat（Triticum aestivum L.） to CO2 enrichment were studied by the method of open top chambers（OTCs）.The results showed that Pn and Ci of the wheat leaves increased with rising of CO2 concentration.Compared to the control,Pn increased at the booting and filling stage significantly（P〈0.05）,increase of Ci in wheat leaves was highly significant at the filling stage（P〈0.01）.Gs and Tr of the wheat leaves had a declining trend and significantly decreased at the filling stage（P〈0.05）.Under CO2 concentration elevated,the trend of changes of Hill reaction activity of wheat leaves increased.The activities of Mg^2＋-ATP and Ca^2＋-ATP in leaves increased at various growth stages.The biomass of wheat increased with the increase of CO2 concentration.And the grain weight of ear increased significantly.The results suggested that CO2 enrichment had positive effect on photosynthesis,biomass and grain yield of wheat ultimately.