Study On The Physiological Characteristics Of Drought And Cold Resistance Of Four Kinds Of Grapes

Grape cultivation area is large in China,and its growth environment is affected by water,temperature and other factors.Grapes are mainly grown in Northwest China,and these areas are faced with drought and low temperature problems,which affect the growth and yield of grapes.In addition to improving cultivation techniques and other methods to solve the problem,it is also very important to study the resistance of grapes.In this study,the physiological characteristics of the annual cuttings and dormant branches of’Zaoheibao’,’Molixiang’,’Muscat’,and ’Heibaladuo’ were studied under drought and cold resistance.Under drought stress,the changes of water content,light and pigment,electrical conductivity(REC),malondialdehyde(MDA),proline,soluble sugar,soluble protein and other physiological indexes of grape leaves were determined under different stress days;In the study of cold resistance,different low temperature treatments were carried out,with 4°C as the control,the test materials were placed at-10°C,-15°C,-20°C,-25°C,-30°C,and-35°C respectively.The changes in the electrical conductivity,malondialdehyde,proline,soluble protein,soluble sugar,peroxidase(POD),catalase(CAT)and other indicators of grape branches under different low temperature treatments were measured.Finally,principal component analysis,correlation analysis,membership function and other methods were used for evaluation.The test results are as follows:1.The results of drought resistance showed that the relative water content,light content and pigment content of four grape leaves all showed a decreasing trend with the prolonging of drought stress time,and the decreasing range of ’Muscat’ was the least.The electrical conductivity,osmotic adjustment substance and malondialdehyde content of leaves showed an increasing trend.The osmotic adjustment substance of’Muscat’ was significantly higher than that of ’Molixiang’,while the electrical conductivity and malondialdehyde content of ’Muscat’ were significantly lower than that of ’Molixiang’.2.The results of the cold resistance study showed that the electrical conductivity of each branch increased with the intensification of low temperature stress,and the increase was different.Combined with the Logistic regression equation,the semi-lethal temperature of the four grapes was calculated.The relative conductivity of ’Molixiang’ was significantly lower than that of ’Zaoheibao’,’Musca’ and ’Heibaladuo’,and the half lethal temperature of ’Molixiang’ was the lowest,which was-29.74°C.3.The physiological characteristics of grape branches after low temperature treatment were determined.The results showed that the germination rate of grape branches decreased with the decrease of treatment temperature;The relative conductivity,soluble protein,soluble sugar content and other indexes showed an increasing trend,but the trends were different.The proline content,POD activity and CAT activity of branches increased at first and then decreased.The content of malondialdehyde increased firstly,then decreased and then increased.4.The results showed that the order of drought resistance of the leaves of the four grape varieties is:’Musca’ > ’Heibaladuo’ > ’Zaoheibao’ > ’Molixiang’;the order of cold resistance of the four grape branches is: ’Molixiang’ > ’Zaoheibao’ > ’Heibaladuo’ > ’Muscat’.