Preliminary Study On Saline-alkali Tolerance Of 10 Table Grape Varieties Introduced Into Xinjiang At Seedling Stage

Xinjiang has excellent geographical and climatic conditions,which is suitable for grape planting,but the soil salinization in this area is more serious,which limits the development of grape industry.Therefore,the screening of salt-tolerant table grapes is of great significance to promote the development of grape industry in Xinjiang.In this study,10 table grape varieties introduced in Xinjiang were taken as the research objects,and the growth indexes and microstructure of grapes after 30 days of saline-alkali stress were observed through pot control experiment.The physiological and biochemical indexes,photosynthesis characteristics were measured,so as to provide a theoretical basis for the further popularization and application of 10 table grape varieties introduced in Xinjiang.The results are as follows:（1）With the increase of saline-alkali concentration,the saline-alkali damage index of 10 grape varieties increased,and the growth of shoot length,stem length and diameter,leaf length and width decreased.Under high concentration of saline-alkali stress,the growth of stem diameter decreased by73.88%in‘Crimson Rose’,and the smallest was‘Blackcrunchy Seedless’,only 30.48%.（2）Observation of leaf anatomical structure of 10 grape varieties showed that under high concentration of saline-alkali stress,the thickness of upper and lower epidermis,palisade tissue,spongy tissue and leaf thickness increased,palisade/spongy tissue decreased,cell tense ratio decreased,and spongy ratio increased.The biggest decline in palisade/spongy tissue is‘Wagamichi’,reaching 22.68%.The smallest decline in palisade/spongy tissue is‘Shine Muscat’,only 3.87%.（3）Comparing the physiological and biochemical changes of 10 grape varieties,it was found that with the increase of stress intensity,root activity and leaf relative water content decreased,relative conductivity,MDA and proline content increased,and superoxide dismutase activity increased first then decreased or had been increasing.The largest increase in relative electrical conductivity of leaves and roots was‘Wagamichi’,which was 58.66%and 18.81%,respectively.（4）The diurnal variations of photosynthesis and fluorescence of 10 grape varieties under saline-alkali stress were determined.It was found that the diurnal variations of net photosynthetic rates of‘Blackcrunchy Seedles’and‘Zitianwuhe’showed a‘single peak’curve,and those of the other eight varieties showed a‘double peak’curve.The highest peak value appeared at 11:00 a day.Among the eight varieties with photosynthetic midday depression,‘Crimson Rose’,‘Wagamichi’,‘Sweet Sapphire’and‘Summer Black’were mainly limited by non-stomatal factors,while‘Silk Road Red Rose’,‘Shine Muscat’,‘Zaoxiawuhe’and‘Hutai 8’were mainly limited by stomatal factors.With the increase of saline-alkali stress concentration,SPAD value,net photosynthetic rate,stomatal conductance,intercellular CO₂concentration,transpiration rate,water use efficiency,initial fluorescence,the maximum fluorescence,actual photochemical efficiency of PSII,the maximum efficiency of PSII photochemistry decreased,and non-photochemical quenching coefficient increased.（5）The principal component analysis of 34 indexes of 10 grape varieties was carried out,and 6principal components were extracted,and the cumulative contribution rate was 85.73%.Finally,the comprehensive score of saline-alkali resistance of each variety was obtained.According to the comprehensive score,10 table grape varieties were sorted:‘Blackcrunchy Seedless’>‘Zitianwuhe’>‘Zaoxiawuhe’>‘Crimson Rose’>‘Silk Road Red Rose’>‘Shine Muscat’>‘Hutai 8’>‘Summer Black’>‘Sweet Sapphire’>‘Wagamichi’.