Identification Of Fusarium Wilt Of Melon Seedlings Inoculated System And Its Application

Fusarium Wilt(Fusarium oxysporum f. sp. Melonis) is an important soil-borne disease, has occurred throughout China. Inoculated at the seedling stage can be used as a method of quickly wilt resistance identification. At present, a reliable system of melon seedling inoculation technique has not been established. So this study first established and improved the identification system of Fusarium wilt of melon seedlings, and then identified the resistance evaluation and studied different grafting methods on Fusarium wilt of melon.The disease resistance of melon to Fusarium wilt was identified with different concentrations of pathogen spores(1×105,1×106,1×107 spore·mL-1) at different seeding stages(cotyledon stage,2 true leaves stage and 4 true leaves stage) by root dipping inoculation. The results indicated that the best concentration for inoculation was 1×106 spore·mL-1 at two leaves stage. Because selection pressure was moderate, the disease index in the 70 or so, and the performance of disease susceptibility was significantly different. And the best time for resistance evaluation was 10 days after inoculation, which would help save time and manpower.The sreening tests of 18 melon common cultivars in production showed that 'Xinjinxuelian','Changxiangyu','Yugu','Chunhui' and 'Milv' had high resistance to melon Fusarium wilt. And the sreening tests of 18 squash cultivars showed that all varieties were highly resistant to Fusarium wilt of melon.Experiment with different grafting methods, the use of plug, root pruning and dock, showed that grafting significantly improved the ability of resistance to Fusarium wilt of melon. However, different grafting methods on resistance to Fusarium wilt were no significant difference. Through the physiological metabolism of self-rooted and grafted seedlings both inoculated with Fusarium wilt, root activity, chlorophyll, MDA and relative conductivity of grafted plants were no significant difference with the control. SOD, POD, PAL activity in the roots of grafted plants were significantly higher than the control.