Effect Of Hypoxia Stress On Growth And Yield Of Melon (Cucumis Melon L.)

Twelve varieties were selected to study difference of tolerance to hypoxia stressin this paper. And Wangwen 2 and Xiyu 1 were adopted to research physiologicalresponse to hypoxia stress. The results were as follows:The growth and chlorophyll content of all varieties were inhibited to variousdegrees undr hypoxia stress after 9 days. The height of Xingyun 52, Jinhui 1 andWangwen 2 was not marked different than that of control. But the height of Xiyu1,Chenglu,Xinmi 13 and Chunlei declined significantly by 45.34%-58.39%.The biomassofシゲナス,Wangwen 2,アンテスand Xingyun 52 declined less but that ofマリナ,Chunlei and Chenglu declined significantly than that of control. The root activities ofXingyun 52 and Wangwen 2 increased by 56.48% and 44.71%, and that of Chunlei,Xiyu 1 and Xinmi 13 significantly declined than that of control. Three varieties ofXingyun 52, Wangwen 2 andアンテスhad resistance to hypoxia stress. However Xiyu 1,マリナand Xinmi 13 were sensitive to hypoxia stress.Two varieties of different tolerance of Wangwen 2 and Xiyu 1 were selected tostudy mechanism of different hypoxia tolerance. The contents of MDA and proline werehigher than that of control of two varieties in hypoxia stress,and the MDA content ofXiyu 1 was greatly higher than that of Wangwen 2.It showed that more harm producedto cell membrane of Xiyu 1.The activities of SOD, POD and CAT were induced inhypoxia. During the earlier stage of treatment(0-50 days), the activities of SOD, PODand CAT to Wangwen 2 were higher than that of Xiyu 1; but that were declined in 50-60days. It indicated the senescence was the main stress to Wangwen 2 but not hypoxia in later stage. The activities of SOD and POD still rose in Xiyu 1, which showed the harmof hypoxia stress continued. The total contents of nitrogen, phosphorus and potassium ofWangwen 2 in leaves were less than that of control in hypoxia stress. The same to thetotal contents of phosphorus and potassium to Xiyu 1.But Xiyu 1's total content ofnitrogen was higher than that of control. At last, the growth was slower and the yieldwas significantly declined to Xiyu 1 in hypoxia stress. This indicated that somephysiological changes could enhance hypoxia resistance to melon, which were moreproline content, less MDA content and smaller range declined of mineral element duringthe whole treatment and higher activities of antioxidative enzymes in earlier treatmentstage but lower in later.