Cucumber(Cucumis sativus L.)is a worldwide vegetable.It's also one of the main vegetable cultivations in our country.Cucumber seedlings are easily affected by drought stress.Water shortage could seriously affect the growth of cucumber yield and quality.Drought is the recurrent factors affecting vegetable production,crop drought resistance mechanism research is increasingly attention.With exogenous substances to alleviate drought stress on crop damage research more and more,such as salicylic acid,betaine,oxa...