Study On The Effect Of Temperature Treatment On The Heat-durability Of Cabbage Seedling

High temperature is the most unfavorable factor in vegetable production. It seriously influences the quality and output of vegetable and is a basic reason for the shortage of vegetables in summer and autumn seasons. Therefore, studies on heat-durability of vegetables are paid to great importance. Up to now there are few reports on the heat-durability of cabbage. Because cabbage is of strong adaptability and anti-adversity, they are easily cultivated, so it has become an important vegetable in China and occupy an important status in anniversary supply of vegetables. The seedling of autumn cabbage is bred in summer when it is hot and rainy, which results in the bad quantity and less anti-adversity of cabbage seedlings, and seriously influences the subsequent yield and quality. Therefore, adopting certain cultivation method to enhance heat-durability of seedlings is of great importance in cabbage production.The material used in the experiment are three cabbages species(Xiaguang, Xiyuan NO. 4, Jingfeng NO.1), They are applied with two temperature treatment methods(different temperature pretreatment and heat-activation treatment) respectively, using the response surface design (including temperature and time two factors). According to the test of seedling heat-damage index, quantitative analyses have been achieve for the heat-durability of cabbage seedlings, and it has been measured for the heat-related physiological and biochemical indexes of three cabbage species in nine combined treatments. Consequently, the physiological and biochemical changes in cabbage seeds after temperature treating are systematically studied. Furthermore, the mechanisms that affect heat-durability of cabbage seedlings are discussed. By the experiment, the best temperature and time treat combinations are acquired for the improvement of cabbage seedling heat-durability, which may provide to cabbage production.1. The result indicates: after treating with temperature, all indexes have positive relation with heat-durability of cabbage seeds such as vitality, proline content, dissolubility protein content, binding water content, SOD activity, POD activity, CAT activity etc, all of them increase as the heat-damage index reducing; those have negative relation with heat-durability such as electrolyte pervasion, MDA content etc. all go down as heat-damage index. The statistics show that,temperature and treat time have remarkable regressive relations with physiological and biochemical index that related with heat-durability of cabbage.2. The influence on heat-durability of cabbage seedling is temperature>time, and temperature has remarkable influence on heat-damage index.3. The result shows that, heat-durability among three species has big difference under the same temperature treatment , the heat-durability is Xiaguang>Xiyuan No. 4>Jingfeng No. l.and after temperature treating , the heat-damage index of these three species is Xiaguang