Abstract:

The effects of different levels of water stress and rewatering on leaf transpiration，photosynthesis and stomatal conductanceof ‘Fenxishi’ plant was studied. The results showed that transpiration rate(Tr)、net photosynthetic rate(Pn)、stomatal conductance(Gs) and water using efficiency(WUE) decreased with the increasing of water stress and the lasting of time while intercellular CO2 concentration(Ci) decreased first and then increased and stomatal limitation value(Ls) increased first and then decreased.The reasons of Pn decreased were stomatal and nonstomatal limitation respectively in light and severe water stresses. After rewatering, the photosynthesis characteristics cannot recovered on the serious stress which did damage to dahlia leaves more earlier.