Study on Physiological Characters of Three Different Cold-resistant Tomato Strains

[Objective] The aim was to study cold-resistant indexes and physiological characters of three different cold-resistant tomato strains selected under natural conditions.[Method] With 21-28 days tomato seedlings as tested materials,through simulating external environment conditions by the cold treatment in lab,the survival ratio and growth status of seedlings were identified;by studying the morphological change of vitro leaves after cold treatment and determining the relative conductivity,the cold-resistant degree of different tomato strains was identified and the correlation between conductivity and survival rate was analyzed;the variation of soluble sugar and proline content in plant of tomato was determined under the condition of cold stress.[Result] The results showed that leaf morphological changes,size of conductivity and growth status of different tomato strains after cold treatment have significant differences;the variation of soluble sugar contents in plant has significant differences,while the variation of proline content has no significant differences.[Conclusion] There is a certain correlation between conductivity and survival rate of different tomato leaves under cold treatment conditions,and plant cold tolerance is related to accumulation of soluble sugar content.