Photosynthesis Light Response Characteristics of Three Ardisia Species

Light simulation experiment on Ardisia sieboldii,A.crenata and A.crenata var.bicolor cultivated under shade and determination by portable photosynthesis system(LI-6400) demonstrated that net photosynthetic rate(Pn),transpiration rate(Tr),leaf temperature(Tf),stomatal conductance(Gs) and water use efficiency(WUE) of three plants increased,while intercellular CO2 concentration(Ci) decreased with low light and enhancement of photosynthetic active radiation(PARi) treatment.When PARi reached 400μmol.m-2.s-1,there had an obvious inhibition of photosynthesis,while PARi topped 800μmol.m-2.s-1,stomatal conductance reduced and stomatal movement were affected.Light saturation point(LSP),light compensation point(LCP) and maximum water use efficiency of three plants were 199.251 8 ~ 281.510 6μmol.m-2.s-1,11.934 0 ~ 51.678 9μmol.m-2.s-1 and 2.27 ~ 7.56 μmolCO2.mmol-1H2O respectively.The experiment resulted that three Ardiasia species had property of shade tolerance and hygrophilous,could adapted indoor environment.Contrastive analysis indicated that A.sieboldii had higher light saturation point and compensation point,greater transpiration rate and stomatal conductance and less variation range of leaf temperature than the other two species.It had better ability to adapt intense light and had stronger growth vigor.