Physiological Response Of Different Grape Rootstocks To NaCl Stress And Screening Of Salt-tolerant Rootstocks

Object:This experiment was carried out to investigate the effect of 100 mmol·L^-1NaCl stress on the growth and physiological indices of potted grape rootstock seedlings of’5BB’,’101-14’,’SO4’,’3309M’,’Beda’,‘Kangzhen 3 hao’,‘Kashhar’,‘Munage’,‘Hetian Red’,and‘Summer Black’.By comparing their salt tolerance,we can provide theoretical support for the selection of salt-tolerant grape varieties.Methods:Different annual grape rootstocks were used as test materials,and two treatments were set up:（1）Control（CK）:watering water;（2）Treatment（T）:Irrigate 100 mmol·L^-1NaCl solution.The water was irrigated for five days,with dosage of 600 m L each time.The 3th to 5th functional leaves of each new shoot were selected on the 15th day of NaCl stress to determine their physiological indicess.Results:After 15 days of 100 mmol·L^-1NaCl stress.The leaves of 10 different grape rootstock varieties showed different degree of salt injury symptoms.Among them,’Hetian Red’,’Munage’,’Summer Black’and’Kashhar’had a small part of the leaf edge scorched and were less affected by salt stress.A few leaves of’101-14’,’Kangzhen 3 hao’and’Beda’were withered and dried,with moderate salt damage.Most of the leaves of’3309M’,’5BB’and’SO4’were scorched,defoliated and died,as a result ofsevere salt damage.Root activity,leaf chlorophyll content,F_v/F₀,PI_ABS,F_v/F_m,Pn,Gs,Tr of’Hetian Red’,’Munage’,’Summer Black’and’Kashhar’decreased less than those of other controls.MDA content and relative conductivity increased slightly.The activities of POD,SOD,CAT and contents of soluble sugar,proline and soluble protein increased significantly.The decrease in GA₃and IAA content and the increase in ABA content were small.Root activity,leaf chlorophyll content,F_v/F₀,PI_ABS,F_v/F_m,Pn,Gs and Tr of the rootstocks’3309M’,’5BB’and’SO4’decreased significantly,while MDA content and relative conductivity increased significantly.The activities of POD,SOD and CAT and contents of soluble sugar,proline and soluble protein increased slightly.The content of GA₃and IAA decreased significantly and the content of ABA increased significantly.Through correlation analysis,principal component analysis,membership function and cluster analysis,it was found that’Hetian Red’,’Munage’,’Summer Black’and’Kashhar’have a high salt tolerance.’101-14’,’Kangzhen 3 hao’and’Beda’have medium salt tolerance.The salt tolerance of’3309M’,’5BB’and’SO4’is weak,which is consistent with the result of the salt hazard classification.The results showed that the membrane permeability,enzyme activities and organic permeable substances of the rootstocks were closely related to their salt tolerance,and the salt-tolerant rootstocks of’Hetian Red’,’Munage’,’Summer Black’and’Kashhar’could reduce the excitation pressure of maximum photochemical efficiency and maintain a high chlorophyll content,thus maintaining the balance between the photosystems.Conclusion:The salt tolerance of the different grape rootstocks were ranked as follows:’Hetian Red’>’Munage’>’Kashhar’>’Summer Black’>’101-14’>’Kangzhen 3 hao’>’Beda’>’3309M’>’5BB’>’SO4’.