Comparison of photosynthetic characteristics and chlorophyll fluorescence parameters of young seedlings of different Carya cathayensis cultivars
In order to provide high efficient cultivation techniques and measures for different cultivars of Carya cathayensis, an experiment was conducted to investigate the photosynthetic characteristics of five C. cathayensis so as to screen cultivars with high light efficiency. The photosynthetic characteristics of the leaves from different cultivars of C. cathayensis of two years old, including net photosynthetic rate(Pn), intercellular CO2 concentration(Ci), stomatal conductance(Gs), transpiration rate(Tr)and WUE etc. were measured by LI-6800 photosynthesis system. The chlorophyll fluorescence parameters, including initial fluorescence(Fv), the maximum fluorescence(Fm), actual photosynthetic efficiency of YII, photochemical quenching coefficient(qP) and non-photochemical quenching coefficient (NPQ)were measured by MINI-PAM-Ⅱof WALZ, Germany. Photosynthetic and chlorophyll fluorescence parameters were analyzed, and the photosynthetic capacity of 5 cul-tivars of C. cathayensis were evaluated by membership function method. As results, there were significant differ-ences in the net photosynthetic rate(Pn), intercellular CO2 concentration(Ci), stomatal conductance(Gs), transpiration rate(Tr)and water use efficiency(WUE). The results of correlation analysis showed that the net photosynthetic rate was positively correlated with Gs and E; Ci was positively correlated with Gs and YII, while it was negatively correlated with qP. Using membership function method, the photosynthefic capacity of 5 cultivars of C. Cathayensis were in the order of Ningguo2> Ningguo4> Ningguo3> Ningguo5> Ningguo1. In conclusion, there were significant differences in photosynthetic characteristics among 5 cultivars of C. cathayensis: Ningguo 2 and Ningguo 3 had higher photosynthetic capacity, higher transpiration rate and lower water use efficiency; Ningguo 4 had the best ability to dissipate excess light energy and heat, and higher ability of light protection. It was suggested that other cultivars should be planted with high-stalk corn for shade.
万方数据
维普
