Effects Of Water Stress On Volatile Flavor Of Cabernet Sauvignon Grape

In order to study the effect of water stress on the flavor substances of Cabernet sauvignon grape,taking 3 years-old wine grapes as experimental material,using a soilless cultivation pattern with "cup"shape training system on grapevine development,according to the water before dawn bits of ?b set four water stress gradient,yet without stress(CK),mild stress(T1),moderate stress(T2)and severe stress(T3),to research the influence of different water stress to grape volatile substances,to fragrance related gene and the influence of the quality.The results showed that:1.Water stress can promote the decrease of aldehydes in different degrees.In the process of fruit development,there are 3 kinds of aldehydes that can be detected.The three kinds of 2-hexanal,E,E-2,4-hexanal and 3-methylbutanal have raw,grassy flavor,aroma characteristics of grapes are not mature.water stress can make the three material presents decline of different degrees,and excessive water stress can inhibit the decrease of aldehydes.2.In the process of fruit development,there are 5 kinds of alcohols that can be detected in this study.2-hexenol is first rise and then decline,and the other alcohols,1-hexanol,2-pentanol,2-hexanol,1-heptanol are gradually increasing,and 2-hexenol can be reduced by T1 treatment.The content of alcohol content,T1 treatment can significantly increase the content of 1-hexanol,2-pentanol,2-hexanol.T2 treatment can significantly increase the content of 1-heptanol,indicating that moderate water stress can promote the accumulation of 1-hexanol,2-pentanol,2-hexanol,1-heptanol,and the excessive water stress inhibits the synthesis of these substances.3.Water stress can significantly increase the expression level of Vvlis,CCDl,HPLA and Vv-Ecar gene,and the 3 genes of Vvlis,CCD1 and Vv-Ecar under T1 treatment are the largest.The expression of HPLA gene is the largest under the treatment of T2.The results showed that moderate water stress had the best effect on the expression of genes related to volatile flavor compounds in grape fruits.4.Proper water stress can promote the improvement of fruit quality,while severe stress is not conducive to the formation of fruit quality.Based on principal component analysis to study the effect of water stress of fruit quality of Cabernet sauvignon grape,water stress has large influence on total phenol,tannin,sugar,and organic acid,the influence of the anthocyanins,soluble solids,reducing sugar,hundred grain weight are little.In a word,water stress has large influence to soluble solids,reducing sugar,anthocyanins,sugar acid,times of tannin and total phenol,at the same time,these quality traits that evaluate the influence of water stress to grape quality of Cabernet sauvignon are important indicators.