Characteristics of Photosynthesis and Chlorophyll Fluorescence Parameters in Gisela Rootstocks Under Salt Stress

The effect of NaCl stress on photosynthesis of one-year 'Gisela' rootstocks seedlings,G6,G5,Y1,and B5,which planted in pots were investigated.The results showed that the content of photosynthetic pigments,photosynthetic parameter,and chlorophyll fluorescence parameter were influenced by salt stress.The parameters of net photosynthesis rate(Pn),stomatal conductance(Gs),transpiration rate(Tr),the value of Fv/Fm,ΦPSII and ETR declined obviously paralleled with NaCl concentration increase and treatment time prolongation in 'Gisela' rootstocks,while B5 reduced more mildly than other species.The differences of NaCl stress on 'Gisela' rootstocks were significantly different among species and controls.PSII of 'Gisela' rootstocks were not destroyed obviously at the beginning and middle of 3‰ and 6‰ NaCl treatment,while were inhibited and destroyed under sever salt stress.Contrasted with other species,B5 seemed to be more tolerant to salinity stress.