Clone Variation of Photosynthetic Index of Catalpa fargesii and Its Relationship with Environmental Factors
Photosynthetic characteristics and chlorophyll content are important indicators of physiological characteristics of trees.This study analyzed the relationship between photosynthetic characteristics,chloro-phyll content and environmental factors as well as genetic variations of Catalpa fargesii clones,aiming to identify the excellent clones with high photosynthesis efficiency.The parameters of photosynthesis and gas exchange were determined by LI-6400 portable photosynthesis analyzer,and the chlorophyll content was determined by SPAD-502 chlorophyll analyzer.The results indicated that significant differences in net pho-tosynthetic rate(Pn),transpiration rate(Tr),stomatal conductance(Gs)and water use efficiency(WUE)existed among the clones.Pn was positively correlated with Tr,Gs and WUE,and negatively correlated with intercellular CO2 concentration(Ci).Pn was negatively correlated with the concentration of CO2 in the air.According to the regression equation,light intensity has significant and positive contributions to in-stantaneous Pn,Gs and Ci.Chlorophyll content was positively correlated with instantaneous Pn,indicating that chlorophyll content directly determined photosynthetic capacity and growth status of C.fargesii.The correlation between photosynthetic indexes and environmental factors was significant.The variation coeffi-cient and repeatability of photosynthetic indexes of the clones were high,and the selection potential of pho-tosynthetic capacity was large.Together with tree height and DBH,chlorophyll content can be used as a key index for better selection of C.fargesii.
国家科技期刊平台
NSTL
万方数据
