Physiological Study On Drought Tolerance Of Xinjiang Wild Walnut

Xinjiang wild walnut are rare wild plant resources in China,it is a direct ancestor of cultivated walnuts.It is mainly distributed in Yewugou Nature Reserve,Gongli County,Yili,Xinjiang.In this paper,12 types of Xinjiang wild walnuts were studied and compared with 4 varieties of cultivated walnuts,the trend of 20physiological indicators under drought stress was analyzed,according to the principal component analysis and the membership function,the drought tolerance was evaluated comprehensively,the main results were as follows:（1）With the prolongation of drought stress time,The RWC,Chl content,Pn,Gs,Tr,Fv/Fm,q P,and ETR of all types and varieties decreased continuously,and increased after rehydration.（2）With the prolongation of drought stress time,The REC,MDA content,H₂O₂content,O₂^-·production rate,Pro content,and Fo of all types and varieties all increased continuously,and decreased after rehydration.（3）With the prolongation of drought stress time,Ci of all types and varieties dropped first and then rose,and then fell after rehydration.（4）With the prolongation of drought stress time,the SS content of various types and varieties showed two kinds of changes.Among them,the small ellipse,iron shell,ellipse and flat bottom round shape continuously rise,and then recover after reducing moisture;other types and varieties rise first and then fall,and then recover after rising.（5）With the prolongation of drought stress time,the SP content of all types and varieties showed three trends.Among them,the small ellipse,iron shell,ellipse,spindle,small round,and triangular shape continue to rise,after the restoration of moisture,they drop;the round bottom,heart shape,oval,Xinxin 2rise first Drop,increase after the recovery of moisture;other types,varieties,then drop after the first rise,restore moisture and then decline.（6）With the prolongation of drought stress time,the SOD activity of various types and varieties showed two trends.Among them,small ellipse,iron shell,ellipse,flat-bottomed round,heart-shaped,thin-shelled,needle-shaped,Ili cultivation,Xinwen 185,rising,other types,varieties rose first and then decreased After water,SOD activity of all types and varieties showed a decreasing trend.（7）With the prolongation of drought stress time,the POD activity of each type and variety showed two trends.Among them,the spindle type,three-angle type,thin shell type,pointed type,Yili cultivation,Hotan thin skin,Xinxin No.2 dropped first and then rose,while other types and varieties continued to rise,and after restoration of water,the type and variety of POD Activity began to decline.（8）With the prolongation of drought stress time,the CAT activity of each type and variety showed two trends.Among them,small ellipse,iron shell,ellipse,flat bottom round,heart shape,pointed fruit,spindle type,thin shell type rising,re-water after the decline;other types,varieties rose first and then fall,restore CAT activity increased after water.（9）Through the principal component analysis,20 individual indicators were synthesized into 7independent comprehensive indicators.The first 7 principal components represented 88.399%of the total data information.At the same time,7 drought tolerance indicators were selected for the subordination through principal component analysis.Function comprehensive evaluation,drought resistance size:Tip fruit type>Iron shell type>Ili cultivation>Xinxin 2>Oval type>Small round type>Oval type>Flat round type>Spindle type>Triangular type>Wada thin skin>Spiked type>Heart type>Small Ellipse type>Shell type>Xinwen 185.