Differential Analysis Of Resistance To Drought And Salt Stress In Different Strawberry Varieties

Strawberry(Fragaria× Ananas Duch.)is a perennial herb with high nutritional value and is deeply loved by many consumers.Strawberry roots are widely distributed in the shallow soil,which is easy to cause water deficit under drought conditions.Moreover,strawberry is mainly cultivated in protected facilities,and improper management of water and fertilizer is easy to cause soil salinization and reduce strawberry fruit varieties and yield.In this experiment,20 varieties of strawberry were propagated by creeping and seedling pressing,and 20 varieties of strawberry were subjected to drought and Na Cl stress respectively.By analyzing the differences of their phenotypes and related physiological indexes,three strawberry varieties with different drought resistance were screened out from20 varieties of strawberry: ‘Sweet Charlie’,‘Huangxiang’ and ‘Yanli’,and then the drought resistance was evaluated in detail after drought and re-treatment.Four varieties with different resistance to salt stress were screened out: ‘Ningfeng’,‘Toyonoka’,‘Tochiotome’ and ‘Snow White’,and then their salt tolerance was evaluated in detail by single concentration salt treatment.By measuring the physiological indexes related to stress resistance of various varieties,the membership function is used to comprehensively evaluate the stress resistance differences of various varieties,and the results are as follows:(1)With the extension of drought stress time,the chlorophyll content and photosynthetic parameters(Pn,Gs,Ci and Tr)of the three types of strawberries showed varying degrees of decline,with ‘Huangxiang’ showing the largest decrease and ‘Sweet Charlie’ showing the smallest decrease;RWC also decreased with the prolongation of drought time,with a smaller decrease in ‘Sweet Charlie’.The MDA and proline content in strawberry leaves significantly increased compared to the control.‘Sweet Charlie’ had the lowest MDA content,while‘Huangxiang’ had the highest MDA content.The overall activity of protective enzymes SODand CAT showed a trend of first increasing and then decreasing.‘Sweet Charlie’strawberry had a relatively higher activity,and after rehydration,the activity of each protective enzyme decreased,By measuring the physiological and biochemical indicators related to drought resistance of three types of strawberries,the membership function was used to comprehensively evaluate the drought resistance ability of the three varieties of strawberries,which ranked from high to low as ‘Sweet Charlie’ >‘Yanli’ > ‘Huangxiang’.(2)With the extension of salt stress treatment time,the chlorophyll,photosynthetic parameters,and RWC of the four strawberry varieties showed varying degrees of decline,with ‘Ningfeng’ and ‘Toyonoka’ showing lower degrees of decline than the other two varieties;Under 150mmol/L salt stress,the proline content of ‘Ningfeng’ and ‘Toyonoka’was significantly higher than the other two varieties,and the MDA content was lower than the other two varieties;The antioxidant enzyme activity showed a trend of increasing first and then decreasing.The SOD activities of ‘Ningfeng’ and ‘Toyonoka’ were significantly higher than those of other varieties,and the salt resistance performance of ‘Tochiotome’ was in the middle position.The physiological and biochemical indicators related to salt tolerance of different strawberry varieties under salt stress were comprehensively analyzed using membership functions.The comprehensive ranking of salt tolerance ability was as follows:‘Toyonoka’ > ‘Ningfeng’ > ‘Tochiotome’ > ‘Snow White’.