Yield And Physiological Characters Of Cucumber Varieties Ang Heat Resistant Difference On Its Seed Germination And Seedling Growth

Heat stress is one of the main environmental factors affecting the yield and quality of cucumber. Therefore, selecting heat-resistant varieties is one of the important goals in cucumber breeding. In this paper, we use 40 different cucumber varieties to study the mechanism of high temperature on the seed and seedling growth and development. The results of germation index and actice oxygen metabolism are as follows:The seed germination was inhibited by high temperature,and differences among varieties were obvious. In the temperature of 42℃, the germination rate, germination potential and bud length dropped significantly, cucumber seedlings appeared obvious spindling. Based on the result of seedling performance, we get 16 heat-resistant materials.The Results of actice oxygen metabolism showed that in heat stress conditins, the leaf cell accumulated MDA. The activity of SOD, POD and CAT was higher than heat-sensitive varieties.Under high temperature stress (42℃), the MDA and PRO content of heat resistance varietie were lower than heat sensitive varieties. the GSH content increased in order to keep harmful toxins into harmless substances then excreted them in vitro. Moreover, in heat resistant varieties, higher AsA-GSH cycle efficiency and GSH content is essential to detoxic the actice oxygen.The comparative experiment of heat-resistant cucumber present excellent characters, papilla, without edges, long fruit and short melon. High yield (8.97t/ha) and excellent quality are adapt to the Wenzhou local residents’ consumption habits. Therefore, YMT can replace WZZHG as new heat-resistant varieties in Wenzhou.