Influences of low temperature stress on different varieties of tomato growth and physiological and bio-chemical index

[Objective]Low temperature stress resistance of tomato varieties which were Tangfen 108,Tang—hong 109, Dongnong 728,Fenguan NO.1,zhongza NO.9 were studied to provide reference for cultivation and cold tolerance breeding of tomato in winter.[Methods]The experiments were carried out at 15 ℃/5℃ and 20 ℃/10 ℃,and at 25 ℃/15 ℃ as check,the illumination intensity was 4000 lx,the treatment time was 15 d.The changes of growth,physiologi-cal and biochemical indexes of tomato seedlings were measured including root activity,chlorophyt,SOD activity,MDA, soluble sugar,POD activity,relative conductivity,proline.[Results]The result showed that the growth index and dry matter of all tomato varieties decreased under low temperature stress.While the changes of physiological and biochemi-cal indexes were different,root activity,chlorophyll,SOD activity decreased,while MDA,soluble sugart,POD activity, relative conductivity and the proline increased with the temperature decreased.[Conclusion]Low temperature stress promoted the increase of MDA,proline and POD activity,and the changes were closely related to cold resistance of dif-ferent tomato varieties.The five tomato varieties cold resistance were listed in an order of Tangfen 108,Dongnon 728, Tanghong109,zhongza NO.9,fenguan NO.1.