遮荫对假俭草抗氧化酶系统及光合作用的影响

研究了不同遮荫条件对假俭草抗氧化酶系统及光合作用的影响,结果表明:遮荫处理后,假俭草叶片的过氧化物酶(POD)、超氧化物歧化酶(SOD)、抗坏血酸过氧化物酶(APX)等保护酶活性、苯丙氨酸解氨酶(PAL)活性以及丙二醛(MDA)含量随遮荫程度的加大逐渐下降,在活性氧产生速率较低的情况下,保护酶活性处于较低状态;可溶性蛋白质及可溶性糖含量随遮荫程度的增加逐渐下降;光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)、水分利用效率(WUE)均随遮荫程度的增加呈下降趋势;胞间隙CO2浓度(Ci)随遮荫程度的增加逐渐上升。遮荫条件下假俭草光合速率降低是非气孔因素所致。对照条件下,假俭草具有很高的光饱和点,意味着该草种具有极高的光能利用能力。随遮荫程度的增加,假俭草光补偿点与光饱和点呈下降趋势,但遮荫处理的表观量子效率(AQY)有不同程度的提高,说明该草对弱光具适应性。因此,假俭草具有良好的应用开发前景。

Effects of Shading on the Antioxidant Enzymatic System and Photosynthesis of Centipedegrass

This paper deals with the effects of different shading conditions on the antioxidant enzymatic system and photosynthesis of centipedegrass.The results showed that being treated with shaping,the activity of protective enzymes such as POD,SOD and APX,activity of PAL and content of MDA declined gradually with the enhanced shading degree.To protect the antioxidant enzymes system is an emergency passive way,when the productive rate of activated oxygen is low,the activity of the protective enzymes is also at a low level.The content of soluble protein and sugar decreased gradually with the enhanced shading degree,so as Pn,Tr,Gs,and WUE.Intercellular space and concentration of CO_2 increased with the enhanced shading degree.In the shading condition,non-stomatal factor arose decreasing of the photosynthetic rate.The light saturation point of centipedegrass was very high in the control,this mean centipedegrass had a high ability in using strong light.The light compensation point and the light saturation point trended to sustaining declined with the enhanced shading degree.While AQY trended to increase in different degree of shading treated.The results indicated that centipedegrass had a adaptability to weak light,and it had good prospect of applying exploitation