Effects Of Exogenous Betaine On Osmotic Adjustment And Cold Resistance Ability Of Cucumber Seedlings

Cucumber(Cucumis sativus L.)originated in the subtropical part of the gourd family,is one of the large scale cultivation of vegetable crops,but also the northern winter and spring production facility vegetable cultivators.Cucumber is a typical cold-sensitive plants are very sensitive to low temperature,so vulnerable in the production of low-temperature damage,causing the yield and quality are affected.Betaine commonly found in plants is very major osmolyte,whose main role is to improve the resilience of the plant.In this study,North China cucumber variety"Jinyou One",the South China type cucumber variety"Jinglonglvfei"for materials to be applied foliar spray and root administered two kinds of exogenous betaine solution,research betaine for hypothermia Stress infiltration and cold resistance ability of cucumber seedlings,aimed initially proved exogenous administration of betaine to improve the mechanism of cold resistance of cucumber and osmotic adjustment,and provide a theoretical basis for the production practice.Obtain the following main results:1.Exogenous Betaine improves to some extent,cold resistance of cucumber seedlings to root application 40mmol/L for the best deal,leaves impose 10mmol/L treatment is the best,root exogenous is better than leaves exogenous.For different types of cucumber varieties,after betaine treatment,different types of varieties performance results,which improve the degree of southern type cucumber variety"Jinglonglvfei"Chilling capacity than North China cucumber variety"Jinyou One".2.Under low temperature stress,cucumber chilling injury index and osmotic adjustment ability was a significant negative correlation,and the two species consistent performance.Exogenous Betaine treatment cucumber seedlings osmotic potential and osmotic adjustment significantly enhanced,can effectively reduce the conductivity and MDA,proline content increased.3.Under low temperature stress,exogenous betaine treatment of cucumber leaves can reduce the magnitude of significantly reduced water potential,osmotic adjustment related to K~+,the level of accumulation of soluble sugar,soluble protein,SOD enzyme,POD enzyme,CAT enzyme,free amino acid content of the significantly increased,and these trends are consistent osmotic significantly decreased Na~+content,thereby increasing the cell water potential of cucumber seedlings,indicating that exogenous betaine may affect osmoticgulation content related substances.4.Under low temperature stress,exogenous betaine of cucumber seedlings,leaf betaine dehydrogenase activity of cucumber seedlings rising cucumber seedlings endogenous betaine content is gradually increased,consistent with both trends.Root Glycinebetaine to T40(40mmol/L)for the best deal,Which is root exogenous is better than leaves exogenous so that endogenous betaine content rose to its highest value and betaine dehydrogenase activity reaches a maximum spraying beet base is L10(10mmol/L)is the best treatment.5.Under low temperature stress,two varieties of cucumber seedling height,root exogenous and leaves exogenous were decreased,after solution treatment with different concentrations of betaine,two varieties of cucumber seedling plant height are rise,which T40(40mmol/L)treatment is best in root exogenous and L10(10mmol/L)treatment is best in leaves exogenous.Under low temperature stress,significantly increased the yield of cucumber exogenous betaine treatment,which T40(40mmol/L)treatment is best in root exogenous and L10(10mmol/L)reatment is best in leaves exogenous.