| Muskmelon Fusarium wilt is a typical soil borne fungal disease,which is a devastating disease in production.When the temperature and humidity conditions are appropriate,the pathogen will quickly produce spores and infect crops.If it cannot be controlled in time,it will seriously affect the yield and quality of muskmelon.In this paper,the pathogen isolation and identification,biological characteristics and disease control of Denglonghong Muskmelon in Wuyuan County,Bayannur City,Inner Mongolia were studied.The main results are as follows:1.Diseased plants were found on Denglonghong Muskmelon in longxingchang Town,Wuyuan County,Bayannur City.The symptoms are that the leaves gradually wilt from the base to the top,accompanied by chlorosis and leaf edge necrosis.Stem base constricted.Rhizome browning,root vascular bundle Tissue Browning,blackening and necrosis.The symptoms are similar to those of Melon Wilt.The pathogen was obtained by single spore isolation.The aerial hyphae of the isolated pathogen were white,while the hyphae were purple and white cotton wadding,and dense.The small conidia are slender oval or spindle shaped,colorless and transparent,and the size is 10.4(2.0 ～ 19.5)μm × 3.0(2.0～3.9)μm.2.Koch’s rule and molecular identification showed that the pathogen was Fusarium oxysporum,and the strains were named XG2 and XG4.After inoculation with strain XG2,the incidence rate of watermelon,Muskmelon,cucumber and Zucchini Seedlings were 60%,80%,80% and 20% respectively;After inoculation with strain XG4,the incidence rate of watermelon,Muskmelon,cucumber and Zucchini Seedlings were 70%,90%,70% and 30% respectively.The ability of the two strains to infect watermelon,muskmelon and cucumber was stronger than that of zucchini,indicating that Fusarium oxysporum,the pathogen of Muskmelon Fusarium Wilt in Wuyuan County,Inner Mongolia,was melon specific(F oxysporum Schl f sp,melonis Snyder&Hansen).3.Strains XG2 and XG4 grew in low sugar medium with diameters of 60 mm and57 mm on the fifth day,respectively,50 mm and 51 mm on the fifth day in urea medium.The medium with different nutrients had a great effect on the mycelial growth of pathogenic fungi.The optimum temperature for mycelial growth of pathogenic fungi was25 ℃;The pathogen can grow at pH 5～9,and the optimum growth pH is 8;There was no significant difference in the growth of pathogens between light and dark conditions.In the constant temperature incubator with light,the light conditions had a certain effect on the formation of mycelial purple pigment of strain XG4.4.The indoor toxicity test of four plant-derived agents on strains XG2 and XG4 showed that the plant immune inducer had the best inhibitory effect on the growth of pathogenic fungus colony,and the antibacterial rate was 41.3%.The EC50 of Osthol to strains XG2 and XG4 were 0.147 g/L and 0.122 g/L respectively,and the recommended inhibitory concentration was 80 mg / L.The pot experiment of four kinds of Fungicides on Muskmelon Fusarium wilt showed that plant immune inducers jm1,JM2,JM3 and Osthol had certain control effects on Muskmelon Fusarium wilt,and the relative control effects were 48.0%,61.4%,15.1% and 65.3% respectively.It shows that botanical fungicide have the potential to control Muskmelon Fusarium wilt,which can be further studied in the field production of muskmelon... |
PDF Full Text Request