Screening And Identification Of Salt Tolerant Mutants Of Cucumber

The available land resource is very limited,but the problem of soil salinization is always threatening our limited available soil resources.About 6%of the world's land is plagued by salinization,especially in arid and semi-arid areas.Soil salinization has a great impact on crop yield due to the high ion concentration,soil compaction,and reduced fertility.In recent years,the area of protected cultivation has expanded rapidly,leading to the gradual expansion of salinized land area,which limits the future development of agriculture in more and more areas around the world.Cucumber is a salt-sensitive vegetable crop widely cultivated,so the soil salinization of the facility has a significant impact on the yield and quality of the cucumber.In this study,the salt tolerant cucumber materials were screened from the 'Changchun Miqi' cucumber mutant library through treating with salt stress.The salt tolerance in gemination stage was evaluated based on the germination rate,germination potential,relative germination rate,and radicle growth status.On the basis of this,we further analyzed the morphological indexes and physiological indexes of cucumber mutant seedlings under salt stress(plant height,root length,stem diameter,fresh weight on the ground,fresh weight of the ground,stem number,SOD activity,POD activity,CAT activity,chlorophyll a content,chlorophyll b content,carotenoid content,soluble protein content).Finally,cucumber mutant materials with a high salt tolerance were screened.The results are as follows:1.A total of 973 mutant materials were classified into salt-tolerant,intermediate and salt-sensitive types based on seed germination experiment under salt treatment.Among them,95 materials showed salt-tolerance,152 had moderate salt tolerance,and the rest were salt-sensitive materials.And 34 salt-tolerant materials were selected from 95 materials for seedling screening.2.The salt-tolerant materials during germination stage were evaluated further in the stage of seedling stage.The external morphology,physiological and biochemical indexes were measured and compared.Combined with the membership index of each single index and the average membership degree,a total of four salt-tolerant mutant materials,numbered 263,345,459,741 were obtained.