Preliminary Study on Photosynthetic Characteristics of Citrus microcarpa in Autumn

The photosynthetic characteristics of Citrus microcarpa were determined with the Li-6400 Photosynthetic system.The results showed that the diurnal variation of net photosynthetic rate (Pn) in Citrus microcarpa was a double-peak curve and there also exists a clear depression at noon.The first peak occurred at 11:00,the second one at 14:00.The maximum of net photosynthetic rate (Pmax) was 3.4467 μmol/m2·s.Correlation analysis showed that there were positive relationship between Pn and transpiration rate (Tr) and stomatal conductance (Gs),and negative relationship between Pn and internal CO2 concentration (Ci).Under the concentration of CO2 400 μmol/mol,the light compensation point (LCP) of Citrus microcarpa was 67 μmol/m2·s,and light saturation point (LSP) was 672 μmol/m2·s.In sum,Citrus microcarpa is a typical masculine and shade-resistant plant which has strong adaptability to the circumstance.