Abstract:In this study, with melon variety ‘Hamilü’ as material, we studied the seed vigor indexes, physiological and biochemical changes, and controlling bacterial fruit blotch of different dryheat treatments (temperature: 70 ℃, 75 ℃, 80 ℃; time: 24 h, 48 h, 72 h). The results as followed: (1) the seed germination indexes and seedling rate of melon significantly decreased with the increase treatment of temperature and time. However, the treatments of 70 ℃ for 24 h and 48 h had no significant effect on seed germination index (except vigor index) and seedling rate. (2) Compared with the control, SOD activity, soluble sugar and proline contents of melon germ increased. At the same temperature, SOD activity and soluble sugar content showed a increasing trend, while proline content decreased with the increase of time treatments; on the other hand, the POD, APX activities and soluble protein content decreased with the increase of temperature and time treatments. Compared with the control, CAT activity decreased of 70 ℃ treatment and increased of 75 ℃ and 80 ℃ treatments, but they were decreased with the increase of time treatments. Compared with the control, changes of O-·2 production rate of 70 ℃ and 75 ℃ treatments had no significant difference, but it increased with the increase of time treatment under 80 ℃ treatment. (3) Compared with the control, seed inoculated Acidovorax citrulli of melon seedlings significantly decreased with the increase of temperature and time treatments. Comprehensive analysis showed that the proper dryheat treatments and times caused enhances in antioxidant enzyme activities and osmotic adjustment substance contents, decreases in O-·2 production rate, as well as increased seed germination indexes and seedling rate. Meanwhile, the results showed that 70 ℃ for 48 h was the effective and safe treatment for melon seeds.