大田增温对夏玉米光合特性的影响

Effects of increasing field temperature on photosynthetic characteristics of summer maize

在大田条件下研究了增温对两个夏玉米品种农大108(ND108)和掖单13号(YD13)光合特性及产量的影响.结果表明:大喇叭口期到成熟期增温显著降低了夏玉米籽粒产量,ND108和YD13的籽粒产量分别较对照降低了46.6%和45.1%;叶面积指数平均值分别降低了15.4%和11.5%;穗位叶叶片光合速率平均值分别降低了22.85%和18.14%;两个玉米品种叶片的叶绿素a和叶绿素b含量显著降低,但对叶绿素a的影响更显著.增温后玉米叶片的磷酸烯醇式丙酮酸羧化酶(PEPCase)和核酮糖二磷酸羧化酶(RuBPCase)活性都显著降低,ND108、YD13叶片的PEPCase和RuBPCase活性分别较对照降低了51.1%、32.4%和29.5%、7.7%.

A field experiment was conducted to study the effects of increasing field temperature on the grain yield and photosynthetic characteristics of summer maize cuhivars ND108 and YD13. The results showed that under increasing field temperature in the period from male tetrad to maturing stage, the grain yield of ND108 and YD13 decreased by 46.6% and 45.1% , leaf area index （LAI） decreased by 15.4% and 11.5% , and net photosynthetic rate of ear leaf decreased by 22.85% and 18.14% , respectively, compared with the control. The contents of leaf chlorophyll a and b, especially that of chlorophyll a, decreased obviously, and the activities of ribulose-1,5-bisphosphate carboxylase （PEPCase） and phosphoenolpyrovate carboxylase （RuBPCase） in the leaves of the two cultivars decreased by 51. 1% and 32.4% , and 29.5% and 7.7%, respectively.