Pathogenicity Test Of Fusarium Oxysporum F.sp. Melonis And Control Technology Of Melon Wilt Disease

Mycosphaerella melonis is one of the most destructive disease in production. We have obtained six isolates from Mycosphaerella melonis grown on PDA plates, their cultural traits including colony color, texture and growth rate and the size of macroconidia are more difference from Fusarium oxysporum f.sp. niveum. Pathogenicity test in seedling stage can not differentiate from the pathogenicity variation of Mycosphaerella melonis. The result of pathogenicity test in adult was indicated that formae speciales and physiological race of isolates from Mycosphaerella melonisare differentiate in differential host and differential cultivars, but the isolates from Mycosphaerella melonis contain Fusarium oxysporum f.sp. niveum. Pcr assay which primers were derived from the differentiation of internal transcribed space (ITS) regions, can prove that difference isolates from Mycosphaerella melonis have no Fusarium oxysporum f.sp. niveum. PCR assay have provided a theoretical basis for controlling Mycosphaerella melonis in our production.The result of toxicity measurement in indoor and chemical control in field indicated that 3% Messenger granule was more effective than general fungicide and used to control Mycosphaerella melonis instead of chemical fungicide, the experiment of grafting, which used the native melon one, Yongkang and Japanese as stock combinating with cion such as Haimi No.3, was showed that can improve resistance to blight and had no difference from self-grafted in survive rate, yield and quality. The native melon one, Yongkang and Japanese used as stock were applied popularly in production and control Mycosphaerella melonis radically.