Effects of Shading Treatment on Photosynthetic Response and Life Cycle form of Taxus chinensis var. mairei

The differences of photosynthetic response,photopigment and life cycle form of 5 years old Taxus chinensis var. mairei which live in the environment of 89% Shading treatment and change the light condition into 46.4% Shading treatment and full light for 50 days was studied.The result showed that the light compensation point of 89% Shading treatment,46.4% Shading treatment and full light was 18.88,30.52,65.34 μmol·m-2·s-1,and the light saturation point was 287.01,258.25,358.92 μmol·m-2·s-1,we can see that the shading treatment can reduce the light compensation point and light saturation point,so the plants can make the best of faint light,height the Photosynthesis rate,enhance the photosynthetic capacity,these changes of 89% is the biggest.Along with the degree increasing of shading treatment,the content of photopigment in the leaves of Taxus chinensis var. mairei which include chlorophyll a,chlorophyll b and carotenoids increased too,and that the ratio of the content of chlorophyll a,chlorophyll b decreased,the result showd that shading treatment can make the best of the light energy,especially blue-violet light,enhance the photosynthetic capacity.We also studied the effects of shading treatment on life cycle form of Taxus chinensis var. mairei,the life cycle form of 89% Shading treatment,46.4% Shading treatment and full light is V0.836C0.164,V0.625C0.375 and V0.772C0.228,the vegetative growth of 89% is the most exuberant.So we can conclude that 89% shading treatment can provide the most suitable condition for Taxus chinensis var. mairei in these three kinds of conditions.