Effect Of Cold Inducement On Physiological Characters Of Cucumber Seedling In Cold Stress

With the cucumber materials Jinyou No.3(cold tolerance),Jinyou No.1(middle variety) and Jinyan No.4(cold sensitive),the effects of cold inducement on physiological characters of cucumber seedling in cold stress solution were studied. The inducement temperatures included 10℃/5℃(day/night),12℃/7℃(day/night) and 14℃/9℃(day/night),and major indexes comprised SOD activity, POD activity, CAT activity, electrolytical leakage, MDA content, soluble sugar content, proline content, soluble protein content and chlorophyll content. The main results were as follows:1. The lamina of cucumber seedling could maintain higher SOD, POD and CAT activity through cold acclimation with feasible temperature. Different treatment with different temperature would lead to different result. In the mass, the impact of treatments, 12℃/7℃and 14℃/9℃, were better than the treatment 10℃/5℃.Different varieties, under the same inducement temperature, appeared similar change trend, however, in different extent. The cold-sensitive cucumber seedling had greater change.2. Through suitable cold inducement, the leaf of cucumber kept lower MDA content and electrolytic leakage. Such result would be appeared under the treatment with 12℃/7℃,1 days, and the treatment with 14℃/9℃,1-2days.3. Feasible cold inducement could increase the contents of soluble sugar, proline and soluble protein in cold stress. The same effects were appeared in the three different treatments,10℃/5℃,12℃/7℃and 14℃/9℃,including 1 to 4 days treatment.4. Jinyou No.3 and Jinyou No.1 ,with the optimal condition, 12℃/7℃,2-3days. Jinyan No.4 ,with the optimal condition,14℃/9℃, 2-3days.