Photosynthetic Characteristics and Canopy Indices of Camellia sinensis Varieties

Photosynthetic characteristics andcanopy indices of 4 varieties of Camellia sinensis were studied forbreeding cultivars with highly efficient photosynthesis, as well as foroptimizing tea cultivation and management. Various physiological propertiesrelating to photosynthesis of Jiulongpao, Zimeigui, Zimudan, and Meizhan teaplants were compared. Their phenotypic traits were basically similar under sameenvironmental conditions. The transpiration rates of the plants extremelysignificantly correlated with the net photosynthetic rate or the stomatalconductance, while the net photosynthetic rate significantly correlated withthe stomatal conductance. But the stomatal limitation value negativelycorrelated with the intercellular CO₂ concentration. Among thevarieties, Meizhan had consistently higher canopy photosynthetic activeradiation (PARi) and effective interception, while slightly lower net photosyntheticrate, than the others; and Zimudan was most efficient on photosynthesis, highon water utilization efficiency, and low on evaporation rate rendering it thechoice cultivar for cultivation in arid regions.