Effect of Leaf Etiolation on Physiological and Biochemical Characteristics of Populus Russkii

In order to discuss the effects of leaf etiolation on Populus Russkii,the contents of physiological and biochemical index under different leaf etiolation grade were measured in this paper.The relations of some index and etiolation grade were analyzed.The results showed that the contents of chlorophyll a,b,a +b,SOD and POD dropped significantly with etiolation aggravation.Water potential within different etiolation leaves decreased firstly and then increased totally.Water potential was higher at 7:00 and lowest at 13:00.Pn presented the double peak trends and peaked at 13:00.Water potential and Pn were higher in normal leaves than in etiolation.MDA increased firstly and then gradually decreased.The content of PPO exhibited irregular fluctuation,which increased at the most serious etiolation grade.There was a negative correlation between every index and etiolation grade.Chlorophyll, SOD and POD were significantly negative correlation with etiolation grade.