Selection Of Related Indexes And Establishment Of Evaluation Method For Cold Resistance Of Vitis Vinifera L.

Vitis vinifera has very high economic value,the evaluation of cold resistance of Vitis vinifera has important guiding significance for grape cultivation and production.The cold resistance of grape during winter is a complex physiological and biochemical process.The evaluation results of a single index have certain one-sidedness and limitations,and it is difficult to accurately reflect the cold resistance of grape.In order to accurately identify the cold resistance of existing Vitis vinifera varieties and intraspecic hybrids,an efficient and simple comprehensive evaluation method is needed.Based on this,this study took the annual dormant branches of 20 Vitis vinifera varieties as experimental materials,identified their cold resistance by four evaluation methods,and conducted correlation analysis between physiological and biochemical indexes related to cold resistance and semi-lethal temperature obtained by different evaluation methods,screened out six representative indexes of cold resistance,and combined the membership function method with the weight of each index.To establish a comprehensive cold resistance evaluation method for Vitis vinifera The main results are as follows:（1）The results of cold resistance identification of Vitis vinifera by different evaluation methods are not completely consistent.The results of EL identification showed that the top 3cold resistance were Ecolly,Meili and Riesling,and the low semi-lethal temperature(LT₅₀)values was-19.42℃,-17.76℃and-17.44℃,respectively.The results of differential thermal analysis（DTA）showed that the top 3 cold resistance of buds were Ecolly,Meili and Italian Riesling,and the semi-lethal temperature(HTE₅₀)values were-10.6℃,-10.5℃and-9.8℃,respectively.The top 3 cold resistance of branches were Ecolly,Meili and Italian Riesling respectively,the HTE₅₀ values were-11.6℃,-11.2℃and-11.1℃,respectively.The results of 2,3,5-triphenyltetrazole chloride staining（TTC）showed that the top 3 in cold resistance were Italian Riesling,Ecolly and Riesling,with LT₅₀ values of-23.74℃,-21.07℃and-20.48℃,respectively.The results of recovery growth method（RG）showed that the top 3cold resistance were Ecolly,Italian Riesling and Meili,with LT₅₀ values of-20.71℃,-20.33℃and-19.67℃,respectively.（2）The membership function comprehensive evaluation method can accurately evaluate the cold resistance of Vitis vinifera Bound water（X1）,soluble total sugar（X2）,proline（X3）,malondialdehyde（X4）,catalase（X5）and ascorbic acid（X6）were the six indexes with the highest correlation coefficient of cold resistance,and their weights were 18.08%,16.74%,17.22%,15.71%,15.17%and 17.09%,respectively.The weight of each index was combined with the membership function method to calculate the cold resistance composite index（CI）,referring to the formula:CI=18.08×RX1+16.74×RX2+17.22×RX3+15.71×RX4+15.17×RX5+17.09×RX6.Where,RX is the membership value of each index.The correlation coefficients between cold resistance index of Vitis vinifera and semi-lethal temperature measured by EL（branch）,DTA（bud）,DTA（branch）,TTC（branch）and RG（branch）methods were-0.938,-0.739,-0.808,-0.709 and-0.763,respectively.