The results were as follows:while water supply tension was increased,soil water content was decreased gradually;the fresh and dry weights of shoot were at the same trend and were the maximum at the point of 30hPa,which was in- creased at the beginning and decreased later;the apparent quantum yield and carboxylation efficiency of Spi.

The results showed that UV-B radiation made a decrease in light-saturated net photosynthesis rate (Ps), Ps at saturating Ci (Pm), apparent photosynthetic quantum yield (AQY), as well as carboxylation efficiency (CE).

Under water stress,the shoot increased rate,the water use efficiency and carboxylation efficiency of two peach varieties were studied under pot cultivation condition.

The tested varieties showed similar responses of net photosynthetic rate (Pn), carbonation efficiency and apparent quantum yield to the photosynthesis active radiation (PAR),having a low and little different light compensation point (50-60μmol m-2 s-1) but a high and different light saturation point (>= 1300μmol m-2 s-1).

Carboxylation rate of Rubisco (RCR), activity of carbonic anhydrase (CA) and intercellular CO 2 concentration (Ci) were analyzed in September and December, 1998, in leaves of forest plants Schima superba, Castanopsis fissa, Psychotria rubra and Ardsia quinquegona seedlings grown at three different light intensities, which were 100%, 36% and 16% of natural sun light.