绿僵菌对小麦纹枯病菌的抑制作用研究

在实验室条件下,研究了金龟子绿僵菌（Metarhizium anisopliae）对小麦纹枯病菌（Rhizoctonia cerealis）的拮抗作用及其机理。结果表明,金龟子绿僵菌与小麦纹枯病菌对峙培养以及在培养基中加入金龟子绿僵菌孢子悬浮液,对小麦纹枯病菌菌丝生长均有较好的抑制作用。测定了培养不同天数的金龟子绿僵菌Ma55发酵液对小麦纹枯病菌菌丝生长、菌核产生量及菌核萌发率的影响。结果表明,液体振荡培养25 d的金龟子绿僵菌Ma55发酵液对小麦纹枯病菌的菌丝生长、菌核产生量及菌核萌发具有显著的抑制作用,且Ma55发酵液中的抑菌活性物质具有较好的热稳定性。在光学显微镜下,未观察到Ma55对小麦纹枯病菌的重寄生现象,但发现金龟子绿僵菌与小麦纹枯病菌对峙培养处小麦纹枯病菌营养菌丝的细胞质变稀薄、菌丝部分消解或断裂。上述结果显示,金龟子绿僵菌对小麦纹枯病菌的拮抗机制主要是营养竞争、空间竞争及抗生作用等。

Inhititory Mechanisms of Metarhizium anisopliae Against Rhizoctonia cerealis

The inhibition and mechanism of Metarhizium anisopliae against Rhizoctonia cerealis was studied in vitro by applying dual-culture,cup-plate test and microscopy,respectively.The results showed that in dual-culture tests and cupplate tests,the tested M.anisopliae had strong antagonism against the tested R.cerealis.It suggested that the inhibitory effects of the tested M.anisopliae on the tested R.cerealis were significant when it was dual-cultured and when its conidia suspension was applied into the PDA media.Using metabolic liquid of Ma55,which was cultured in different time,the inhibitions to hyphal growth,scierotium-fonnation number and sclerotium weight,sclerotiiim-genninating rate were studied,too.The results showed that the metabolic liquid cultured 25 d has significant inhibitory effect on hyphal growth,sclerotium number and sclerotium-germinating rate.The lest indicated that the culture filtrates of Ma55 contained a thermal stable antifungal compound.It was also observed that the hyphal of Metarhizium anisopliae and Rhizoctonia cerealis has no hyper parasitism,but the hyphal of Rhizoctonia cerealis was lysed,broken and their cytoplasm became thinning on dual culture.The results mentioned above indicated that the inhibitory effects of Metarhizium anisopliae against the pathogen of wheat sharp eyespot were produced mostly by nutrition competition,space competition and antibiosis.