光照强度对马蹄金保护酶活性和光合特性的影响

Effects of Light Intensity on Protective Enzymes and Photosynthetic Characteristics of Dichondra repens

通过盆栽试验,利用遮荫网设置光照梯度(透光率分别为100%、76.19%、59.27%、38.09%),研究了光照强度对马蹄金生理指标和光合特性的影响。结果表明,随着光照强度的降低,马蹄金叶片中SOD、POD、CAT活性均逐渐增大;O2-含量和MDA含量均呈下降趋势,说明高度遮荫马蹄金叶片膜系统受到伤害;叶绿素a和叶绿素b均表现出上升的趋势,叶绿素a与叶绿素b的比值逐渐下降;光合有效辐射、净光合速率和蒸腾速率逐渐降低。光合有效辐射均呈"单峰"型,最高峰出现在13∶00。遮荫条件下T1处理蒸腾速率最大。高度遮荫不利于马蹄金的生长。

The effects of different gradients of artificial light intensity（100%,76.19%,59.27%,38.09%） on physiological indexes and photosynthetic characteristics in Dichondra repens were studied with pot experiment.The results showed that：（1） The SOD,POD and CAT activity in leaves increased gradually with decreasing of light intensity.（2） The content of O-2 and MDA in leaves decreased gradually with decreasing of light intensity.It indicated that the higher shading made the membrane system in leaves of Dichondra repens damaged.（3） The content of Chla and Chlb in leaves increased,the value of Chla/Chlb decreased gradually with decreasing of light intensity.（4） The PAR,Pn and E in leaves decreased with decreasing of light intensity.The figure of PAR was one-peak-curve and the highest apex appeared at 13：00.The traspiration rate of T1 was the maximal.The results indicated higher shading was not good for the growth of Dichondra repens.