刈割对热研13号柱花草光合特性的影响

Effect of defoliation on photosynthetic characteristics of Stylosanthes guianenesis cv. Reyan No.13

在盆栽条件下,用20,40和60 d 3个刈割周期与5,15和25 cm 3种留茬高度组合为9个刈割处理,对热研13号柱花草的光合特性进行研究。结果表明:刈割周期和留茬高度的互作对柱花草光合特性的影响,气孔导度(Gs)和蒸腾速率(Tr)达到显著水平,其他指标均不显著。高频次低留茬(20 d 5cm)刈割处理的柱花草光合速度(Pn),Gs,胞间CO2间浓度(Ci)和Tr均最高,分别达到了20.52μmolCO2/(m2.s),0.49μmol/(m2.s),318.89μL/L和11.32 mmol/(m2.s)。而低频次高留茬(60 d 25cm)刈割处理柱花草的WUE最高,达到了2.75μmol CO2/(mmol.H2O)。

The effect of defoliation on the photosynthetic characteristics of Stylosanthes guianenesis cv. Reyan No. 13 was studied with potted plant and 9 treatments, involving 3 defoliation intervals （20,40 and 60 days） and 3 stubble heights （5, 15 and 25 cm）. The results showed that the effect of different defoliation intervals and stubble heights on net photosynthetic rate （Pn）, stomatal conductance （Gs） and transpiration rate （Tr） was significant （P〈0.01）, but it was not significant on intercellular CO2 concentrations （Ci） and water use efficiency （WUE）. The effect of different stubble heights on Ci was significant （P〈0.01）, but not on WUE. The Pn, Gs, Ci and Tr were the highest while the highest cutting frequence and lowest stubble height were applied and reached 20.52/lmol CO2/（m^2·s）,0.49 umol/（m^2·s）,318.89 uL/L and 11.32 mmol/（m^2·s） respectively, but the WUE was the highest while the lowest cutting frequence and highest stubble height were applied and it was 2.75 umol CO2/（mmol · H2O）.