This study examined the difference of competition,hyperparasitism,antibiosis and disease prevention effect of several Trichoderma strains against Fusarium oxysporium f.sp.cucumerinum.The high effective strains were screened for providing theoretical basis for Trichoderma controling soil borne diseases.The results of confrontation culture experiment showed that the tested Trichoderma strains restrained the spread of F.oxysporum mycelia.Among which,the Trichoderma harzianum TH strain had the strongest competition,its mycelia inhibition rate was 67.70％.Trichoderma strains could parasitize in the hyphae of F.oxysporum through clinging,intertwining and penetrating,and finally cause breakage of the hyphae and leakage of the cell contents.The metabolic substances from different Trichoderma strains obtained through a sterile membrane filtration had obvious antibiotic effect.The inhibition zone diameter of TH strain metabolites reached 3.9 cm with a mycelia growth inhibition rate of 57.19％ and spore germination inhibition rate of 68.35％.The results of pot experiment showed that cucumber fusarium wilt was controlled at different levels by the application of Trichoderma strains during seedling period.The TH strain had the strongest effect on disease prevention of 64.34 ％ in control efficiency,Trichoderma viride TV strain behaved the highest promotion effect on cucumber seedling growth.The fresh weight of overground part and underground part of cucumber seedlings increased 42.81％ and 86.92％,respectively.%比较不同木霉菌株对黄瓜枯萎病菌的竞争作用、重寄生作用、抗生作用和防病作用的差异,筛选出高效菌株,为利用木霉菌防治土传病害提供理论依据.通过与致病菌对峙培养,研究竞争作用.结果表明:供试木霉菌能限制黄瓜枯萎病菌的菌丝扩展,哈茨木霉(Trichoderma harzianum)TH菌株竞争作用最强,菌丝扩展抑制率为67.70％.试验发现木霉菌株能够通过紧贴、缠绕、穿透等方式寄生于黄瓜枯萎病菌的菌丝上,最后引起菌丝断裂,细胞内容物外泄.通过无菌滤膜过滤获得的不同木霉菌代谢产物抗生作用明显,TH菌株代谢产物的抑菌圈直径达到3.9 cm,对黄瓜枯萎病菌的菌丝生长和孢子萌发的抑制率分别为57.19％和68.35％.盆栽试验结果显示,育苗时施加木霉菌株不同程度控制苗期黄瓜枯萎病的发生,TH菌株防病作用最强,防效为64.34％,绿色木霉(Trichoderma viride)TV菌株促进黄瓜生长作用最强,地上部分和地下部分鲜质量分别增加42.81％和86.92％.
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