Effects Of S3307 On Physiologocal And Biochemical Characteristics Of Cucumber (Cucumis Sativus L.) Seedlings Under Salt-Stress

Cucumber seedlings(Cucumis sativus L.)of two cultivars(Jinchun No.3,tolerant to salt-stress;Jinza No.4,sensitive to salt-stress) sensitive significantly to salt-stress was selected as material in this study by mensutating modal index, osmotic adjustment, membrane lipid peroxidation ,enzyme activity and endogenesis hormone content in cucumber seedlings to research the effects of S3307 soaked on salt-stress and affecting mechanism.And the same time, the difference of two cucumber cultivars are comparied.The results showed that:The results indicated that the seedlings height of which seed soaked by S3307 were decreased ,while the leaves area, activities of roots,fresh weight and dry weightof top ,fresh weight and dry weightof root of soaking seedling were increased.The alleviation effect to salt-stress are not the same in two cucumbers,Jinza No.4 is more than Jinchun No.3.All the three concentration of S3307 prouduce alleviation effect on inhibition of vucumber seedling under salt stress,but the concentration of 20 mg·L-1 is best.Under satl-stress,relative water content of seedling leaves which was soaked seed by S3307 were improved,however,the diffetence was not distinct between two cultivsrs.The contents of soluble sugar in seedlings soaked by S3307of concentration 20mg/L was higher than the control during the 10th day to the 15th day.It was showed that the S3307 have expansive effect about soluble sugar of cucumber seedlings.Medium and higher concenteation S3307 promoted the contents of proline of Jinza No.4 under the salt-sress.The accumulate extents of proline and soluble sugar to Jinza No.4 were higher than that of Jinchun No.3.It is showed that S3307 have the obvious adjustments to the sensitive cultivars than the tolerant cultivars.Under salt-stress the soaked seedling membrane damagede degree was lower obviously than the seedling without soaked.Membrane lipid per- oxidation production MDA come into being tardily,the contents of MDA low and change in the parochial bound.The activity of SOD was increaed,the activity of POD and CAT decreased tardily.It may be the close connection with the metabolize adjustment.After the trail,it is showed that S3307 have well effect in sensitive variety than the tolerant variety.The best concentration of S3307 is 20 mg·L-1.Under the salt-stress the activity of resistant oxidation enzyme to Jinchun No.3 was higher than the Jinza No.4.The results indicated that the content of ABA of seedling soaked in S3307 increased under salt-stress,while the content of IAA and GA3 are reduced.Under the salt-stress the soaked seedling GA3/ABA occurred improved tardily then descend. On quinquefoliolate stage leaves,the ratio of GA3/ABA in the same level no matter what concentration soaked,or under the contrast. The IAA/ABA variational current of Jinchun No.3 and Jinza No.4 put up nuance,however there was differential advance during the long time.To quinquefoliolate stage,the various hormone level are in the same plane.It is more important that the relative content and balance of hormone than single hormone in aspect of seedling development.