Research On Response Mechanism Of Water-controlling With Drip Irrigated Regulation Quality For Brewing Grapes At Cold Arid Irrigation District Of Hexi

Drip irrigated experiment for regulated deficit of water was carried out at base in Wuwei of Gansu Province from May to October,2014.In oder to obtain mechanism of water-controlling with drip irrigated regulation quality,save water for brewing grapes and provide irrigation system of high quality with theoretical basis,soil moisture,physiological and biochemical characteristics,endogenous hormoneq,characteristics of changes in quality and their mautul correlation were studied under different water gradient-controlling levels.The results of the experiment were showed as follows:(1)Fluctuation amplitude of soil moisture increases with the advance of growth period.The germination period under the condition of water stress,soil moisture bewteen 0 to 100 cm in mid-enlargement period show obvious "rewatering compensation" effect.Soil moisture at 80 or 100 cm on moderate water deficit(60～65% field moisture)of new shoot period response is most sensitive.The moderate moisture gradient control in this period can significantly reduce the flowering period of each soil moisture,affect blossom and fruit of grapes,after severe drought stress(50～55% field moisture),0 to 80 cm in time also appeared rewatering compensation phenomenon.Fruit enlargement period of severe water deficit,soil moisture at coloring maturity period showed a flat elevated recovery trend.Coloring maturity period,severe water regulation ability to reduce the moisture content is far greater than the moderate stress level,it is not conducive to fruit ripe.(2)Water regulaton of field moisture can significantly improve activity of antioxidant enzymes SOD、CAT at later stage of birth in the flowering stage from50% to 55%.It enhanced the defense function of membranous system,severe water deficit of the enlargement period reduce the activity of SOD to some extent,it is not conducive to grape adaptation under drought stress.Grape severe water stress in early and middle stage,the late between 60% to 65% of field capacity water regulation level for the best irrigation mode guarantees of membrane lipids from MDA damage.Germination period of regulated deficit irrigation,the content of Pro significantly increase in maturity period,regulate cell osmotic potential in time,prevent cell dehydration.Full irrigation(80% to 85% field moisture)in expanding stage lead to Pro level in a downward trend,reducing the resistance of grape.(3)ABA generation and accumulation in grape leaves of sever water deficit during the whole growth period was significantly higher than moderate water stress.it can better reduce stomatal conductance,induce stomatal closure reduce leaf transpiration,quickly adapt to drought stress.The content of IAA is the most sensitive to field moisture from 50% to 55%deficit gradient after germination period of severe water stress.IAA generation amount is the largest.It is most conducive to the development of fruit.(4)The germination period is the best water deficit stage.The addition of anthocyanin is maximum between 50% to 55% of field moisture.After moderate water deficit,longitudinal diameter in the late growth stage increased greatly.The new shoot growth period of severe RDI,fruit total sugar generation at least,60% to 65% field moisture irrigation could significantly increase the grape spike weight.Field moisture from 60% to 65% irrigation in flowering period can significantly improve the content of tannin,phenol in fruit,rich fruit aroma flavor.Severe water deficit,tartaric acid under the fastest growth rate.Expanding period of 80～85% field moisture gradient irrigation can improve sugar accumulation,but it will lead to the continued decline of tannin content;after moderate water stress,fruit diameter growth rate is more and more big with the growth development.The maturity period of moderate deficit is most conducive to increase fruit organic acid and anthocyanin content of grape and improve grape flavor and color.The middle growth period of moderate water deficit can effectively reduce the fruit titration acid accumulation.Each growth period of water stress were to some extent reduce the content of dry matter.The new shoot growth period of severe water deficit,acid,tannin,phenolic,anthocyanin,vertical and horizontal diameter,panicle weight were associated with a significantly positive related to soil moisture,soil moisture and grape quality exists an extremely significant correlation.(5)During the period of moderate regualation deficit of germination,the activity of SOD increased significantly.Acid and SOD activity between soil moisture changes are in direct proportion.Total sugars,anthocyanin was positively correlated with ABA,ABA as the variation of soil moisture with the increase or decrease,fruit total sugar,acid content is the highest,fruit sweet sour taste is the most suitable,content of anthocyanin is highest,skin color and lustre is good,dry matter and panicle weight are high,this period is the optimal deficit period to enhance grape fruit quality.Flowering period of moderate water stress,IAA content decreased significantly with the decreasing of soil moisture,dry matter and transverse diameter is smaller.Tannin and CAT activity showed a significant negative correlation,tannins,phenols content was highest,fruit aroma,flavor is the best.