在大田试验条件下设7万(T1)、8万(T2)、9万(T3)、10万(T4)和11万株/hm²(T5)5个处理,测定玉米叶面积指数和叶绿素含量、净光合速率(Pn)、气孔导度(Gs)、胞间二氧化碳浓度(Ci)、蒸腾速率测定(Tr)和玉米产量,研究不同密度对利民33光合特性及产量的影响.研究结果表明,在吐丝期T4密度下LAI最高,在灌浆后期T2密度下LAI最高;在吐丝期和灌浆后期叶绿素含量均随着密度的增加呈降低趋势;吐丝期和灌浆后期净光合速率和光能利用率均表现出T2密度下最高,玉米产量与净光合速率和光能利用率密切相关.利民33在T2密度条件下光能利用率最高,产量最高,达12 124.64 kg/hm².

In order to clear about the effects of high density on photosynthetic characteristics and yield, a field experiment was designed with five treatments: 70 000, 80 000, 90 000, 100 000 and 110 000 plants/ha. In the experiments, leaf area index(LAI), chlorophyll content(CC), photosynthetic rate(Pn), stomatal conductance(Gs), internal CO₂ concentration(Ci), transpiration rate(Tr) and yield were measured. The results showed that the LAI peaked in silking stage and T4 was the highest, but in the late filling stage, T2 was the highest. The content of Chlorophyll decreased in response to the increased density at silking stage and late filling stage; the highest photosynthetic rate and light use efficiency(LUE) was T2 treatment at silking and late filing stage. The yield trend was similar to the photosynthetic rate and light use efficiency(LUE) and closely related with net photosynthetic rate and light use efficiency(LUE).The highest light use efficiency (LUE) and yield was T2 treatment. The yield reached 12 124.64 kg/ha.

国家科技支撑计划项目(2011BAD16B10,2012BAD04B02)