The Response Of Photosynthesis System To Drought Stress Of Five Species Of Landscape Plants

To study the tolerance to drought stress of commen landcape plants, Buxus megistophylla、Photinia serrulata、Hedera nepalensis var. sinensis、Fatsia japonica、and Parthenocissus tricuspidataas were selected as the experimental materials. Natural drought treatment was carried out in the greenhouse. Physiological indicators of plants under drought stress were determined, such as Soil water content(SWC)、Relative water content (RWC)、Carbon isotope discrimination(CID)、Chlorophyll content(Chlt)、Relative electric conductivity(REC)、Photosynthetic parameters and Chlorophyll fluorescence parameters. It was supposed to find out how the five species of plants handle with droutht stress and sort the five ones based on their tolerance to dought stress to see whose endurance is strongest,whose weakest. The results as follows:1The response of RWC、EC、Chlt to drought stress of five species of landscape plants:With the SWC declining, RWC、Chla、Chfb、Chlt increased at the beginning, then decreased. Chl(a/b) declined clearly in the later period, however, the EC rised without a stop in the whole period.2The response of photosynthetic parameter to drought stress of five species of landscape plants: Pn and Tr declined under drought stress, clear enough for the Photinia serrulata、Hedera nepalensis var. sinensis、Fatsia japonica. Ci,on the contrary, increased under drought stress. The reason of why the photosynthesis of plants crippled was for the limit of non-stomatal factors.3The response of chlorophyll fluorescence parameters to drought stress of five species of landscape plants:the influence of the drought stress to the chlorophyll fluorescence parameters of plants was clear. Fo and NPQ rised while Fm、Fv/Fm、Qp、ETR、Y(II) declined.4The response of CID to drought stress of five species of landscape plants:△13C went up under drought stress.Subordinate function analysis was used to rank their drought tolerance and the order was: Buxus megistophylla>Photinia serrulata>Hedera nepalensis var. sinensis> Fatsia japonica> Parthenocissus tricuspidata...