Effects Of Soil Different Drought Conditions On The Growth And Related Physiological Characteristics Of Grape Cutting Seedlings

Turpan is specialize as high temperature,less rainfall,less plant diseases and insect pests,adapt to the grapes(Vitis vinifera L.)growth and development,is main producing areas with raisins in China.In recent years,with the increase of land reclamation and industrial water demand,the deficit of water resources used in agroforestry in Turpan area is becoming more and more prominent,therefore,can screening and breeding of grape cultivars with cold resistance and high yield quality has important practical and theoretical significance for the sustainable development of the grape industry.This study takes Turpan main cultivated grape cultivars 5BB,Thompson seedless,Centennial seedless,Flame seedless,Huozhouheiyu and SP9715 annual cuttings as research object,used pot-cultivated water treatment method,firstly studied the changes trend of main vine growth,drought damage index,leaf relative electronic conductivity,leaf water potential and total chlorophyll content of 6 grape cultivars under the natural drought treatment,and preliminary identified drought resistance ability of 6 grape cultivars by membership function comprehensive evaluation method,secondly selected two grape cultivars Thompson Seedless(drought resistance cultivar)and Flame seedless(drought sensitive cultivar)as the test materials,used pot simulated drought treatment method,study the effects of soil different drought stress on leaf relative electronic conductivity,relative water content,photosynthetic pigment content and chlorophyll fluorescence parameters.The main results obtained are as follows:1.With the extension of the natural drought treatment days,the main vine growth of 6 grape cultivars also showed a decreasing trend.After natural drought treatment 18 days,5BB have a maximum total growth,value is 20.32 cm,the second is Thompson Seedless,Flame Seedless have a minimum total growth,value is 12.62 cm.The order of drought damage index of 6 grape cultivars are Flame Seedless>Centennial Seedless>Huozhouheiyu>SP9715>Thompson Seedless>5BB.2.The leaf relative electronic conductivity of 6 grape cultivars expressed slowly uptrend with the increasing of drought treatment days.Natural drought treatment time was in 6 days,all of grape cultivars are not subject to drought injury;treatment for 12 days,all grape cultivars are subject to different degrees drought injury except 5bb,among them flame seedless’s leaf relative electronic conductivity is the highest,than the control high 68.77%;after 18 days drought treatment,6 grape cultivars almost all are subject to drought harm.3.With the increase in the natural drought treatment days,leaf water potential of 6 grape cultivars were also slowly decreased.Compared with 0 day,the decline degrees of leaf water potential of 5BB in 18th day is minimum,followed by Thompson Seedless,Centennial Seedless decline the highest,the difference is-15.27 bar.4.The total chlorophyll content of 6 grape cultivars were slowly reduced with increasing of drought treatment days.Compared with 0 day treatment,there were no significant difference on total chlorophyll content of all grape cultivars after 6 days drought treatment,but the drought treatment to 12th days,all of grape cultivars5 leaf total chlorophyll content began to decrease significantly,and drought treatments to the 18th day,the chlorophyll content of 5BB is the highest,compared with control treatment than low 0.71 mg/g,total chlorophyll content of Flame Seedless is lowest,value is 0.718 mg/g,the difference with the control for 1.34 mg/g and low 65.06%.5.The research results on Thompson Seedless and Flame Seedless cultivars with simulated drought treatment shows that the leaf relative water content of Flame Seedless under T1,T2 and T3 treatments were significantly lower than those control(CK),but there were no significant difference on leaf relative water content of Thompson Seedless under T1 and T2 treatment compared with CK,and it’s T3 treatment is significantly lower than CK.6.With the decrease of soil relative water content,the photochemical quantum efficiency(Fm/Fv),the actual quantum efficiency of PS II(OPS Ⅱ)and photochemical quenching coefficient(QP)of two grape cultivars had a slow decline,and the electron transfer rate(ETR)showed trend as decreased after increased,among all treatments the T2 treatment have maximum ETR,the ETR of Flame Seedless and Thompson Seedless under T2 treatment are 2.486 + 0.088,0.794 + 0.050,respectively.In short,the drought resistance strength order of 6 grape cultivars is 5bb>Thompson Seedless>Huozhou heiyu>SP9715>Centennial Seedless>Flame Seedless.