The Mechanism Of Cold Resistant Of Typical Wine Grape In Ningxia Province

Wine grape is a characteristic crop in Ningxia.The eastern foot of Helan Mountain in Ningxia is one of the best wine grape producing areas in the world.Wine grape likes warm weather and can't grow well in cold area.Therefore,the grape trees are buried into the soil in the area north of 35 ° n in China,so that the grape trees can live through the winter safely.So,how to improve the cold resistance abilities of grape trees and choose the right time to bury grape trees into the soil has become a very important problem to be solved.Based on the actual situation of the production area,three sets of experiments including different loading capacity,different age of the tree and different stages of natural cold acclimation were designed,to study the effects of low temperature on both the micro physical structure and the physiological and biochemical indexes of wine grape under different treatments.On this basis,the mechanism of cold resistance abilities of wine grape was discussed.The main results and discussion are as follows:There is a significant difference between the effect of different loading capacity on the micro physical structure of one-year old grape branches,and it is not the smaller the loading capacity is,the stronger the cold resistance abilities of grape branches will be,but with the right amount of loading capacity,the cold resistance abilities of grape branches can be improved.Different loading capacity also has a similar effect on the physiological and biochemical indexes of one-year old grape branches.Under the artificial freezing treatment,there was no significant linear correlation between the relative conductivity and the loading capacity.But generally,the higher the loading capacity is,the higher semi lethal temperature grape branches can reach;the total soluble sugar content shows a trend of decreasing slightly at first,then rising and then falling,but the peak temperature of each treatment is different.There is a more obvious linear relationship between the loading capacity and the growth of soluble sugar.With the increase of loading capacity,the growth of soluble sugar also increases gradually,but there is no significant difference between the increase of soluble sugar of 5 kg treatment and 6 kg(CK)treatment;the content of MDA generally increases at first and then decreases.Higher loading capacity leads to the greater growth of MDA content in the whole freezing process,and also the bigger quantity of the maximum MDA content;Three kinds of anti-adversity enzymes work together to resist the low temperature adversity,and the anti-adversity enzyme activities of different loading capacity grape branches are significantly improved,and the overall activity increases with the loading capacity.The trend of activities increases first and then decrease.Applying the principal component analysis method to analyze the physiological and biochemical indexes of the branches,and combining the physical microstructure and the physiological and biochemical data of the branches,it can be concluded that the cold resistance of the branches is the best when the loading capacity is 5 kg,so it can be determined that the most suitable loading capacity of wine grape with the best cold resistance abilities is 5 kg.There is a significant difference between the effect of tree age on the micro physical structure of grape branches,and it is not that the smaller or larger the tree age is,the stronger the cold resistance abilities of the branches will be,but an optimal tree age has the best cold resistance abilities.Before that,the cold resistance abilities of the branches increase gradually,and after reaching the best tree age,the cold resistance abilities begin to fall.There is a similar effect of tree age on the physiological and biochemical indexes of grape branches as well.Under the artificial freezing treatment,the relative conductivity combined with the semi lethal temperature,shows that the larger the tree age is,the lower the semi lethal temperature is;the soluble sugar content shows the trend of rising at first then declining,But the turning points are different.It shows that with the increase of the tree age,the growth of soluble sugar content of branches has a trend of increasing first and then decreasing,and the inflection point is 10 years old;MDA content generally shows a trend of increasing at first then decreasing.With the increase of tree age,the maximum value of MDA content shows a trend of increasing at first then decreasing.The inflection point is 10 years old,and the growth of MDA content has the same trend.Three kinds of anti-adversity enzymes work together to resist the low temperature adversity,and the anti-adversity enzyme activities of grape branches of different tree ages all increased.Generally speaking,there is a trend that the activities of anti-adversity enzyme increases at first and then decreases with the increase of tree age.Applying the principal component analysis method to analyze the physiological and biochemical indexes of the branches,and combining the physical microstructure and the physiological and biochemical data of the branches,it can be concluded that the cold resistance abilities of the branches is the best when the tree age is 10-15 years.Therefore,it can be determined that the best tree age is 10-15 years when considering the best cold resistance abilities.With the increase of natural cold acclimation time,as for the physical anatomy structure,the cold resistance of the one-year old branches of the two varieties is increasing,the cold resistance abilities of Bei Hong is stronger than that of Cabernet Sauvignon,and the response to natural cold acclimation of Bei Hong is also stronger than that of Cabernet Sauvignon.In the process of cold acclimation,the relative conductivities of the two varieties decreased to a certain range and began to fluctuate.It can be concluded from the range of change that the response of Cabernet Sauvignon to cold acclimation is stronger than that of Bei Hong,and there is no significant difference in cold resistance abilities between the two varieties at the later stage of cold acclimation;the content of soluble sugar decreases at first then increases,In terms of the increase of soluble sugar content,the response of Cabernet Sauvignon to cold acclimation is stronger than that of Bei Hong,but the soluble sugar content of Bei Hong is higher than that of Cabernet Sauvignon in most periods,that is to say,the cold resistance of Bei Hong is stronger than that of Cabernet Sauvignon;the MDA content shows different changes.In the early stage of cold acclimation,Bei Hong appeared the response to low temperature stress.With the increase of cold acclimation time,it gradually began to respond to cold acclimation and gradually improved its cold resistance.In the early stage,Cabernet Sauvignon appeared a faster response to cold acclimation,but in the middle and late stage of cold acclimation,due to the low temperature,the self-regulation ability of plants could not continue to resist low temperature stress,so there was a response to low temperature stress at first;Three kinds of anti-adversity enzymes work together to resist the low temperature adversity,and the antiadversity enzyme activities of grape branches in different cold acclimation periods were increased,and the increase of Bei Hong was higher than that of Cabernet Sauvignon,which could be concluded that the overall cold resistance abilities of Bei Hong is stronger than that of Cabernet Sauvignon.The results showed that under the same cold acclimation condition,the response of Bei Hong to cold acclimation is higher than that of Cabernet Sauvignon,and the overall cold resistance abilities of Bei Hong was stronger than that of Cabernet Sauvignon.In terms of burial time,the best burial time for Cabernet Sauvignon is in late September.