球孢白僵菌对3种苹果病原真菌的抑制作用

摘要

为了研究球孢白僵菌(Beauveria bassiana)对果树病原真菌的抑菌活性,在实验室条件下,测定了球孢白僵菌BD-B180菌株对苹果腐烂病菌(Valsa mali Miyabe et Yamada)、苹果轮纹病菌(Physalospora piricola Nose)、苹果斑点落叶病菌(Alternaria mali Roberts)3种苹果病原菌的抑制作用.结果表明,对峙培养中,球孢白僵菌BD-B180对3种病原菌均有抑制作用,其中,对苹果斑点落叶病菌的抑制效果最好,其次为苹果轮纹病菌和苹果腐烂病菌,最高抑制率分别为45.08％、41.35％和39.74％.在加入BD-B180孢子悬浮液的PDA培养基上接种苹果病原真菌,3种真菌菌丝生长均受到不同程度的抑制,抑制程度随孢子浓度的增加而增强.当孢子悬浮液浓度为2.49×107 cfu/mL时,对苹果轮纹病菌的抑菌效果最佳,最高抑制率达90.81％,对苹果斑点落叶病菌和苹果腐烂病菌的最高抑制率分别为77.14％和52.78％.BD-B180发酵液的抑菌效果随着发酵天数的增加而增强,振荡培养20 d的发酵液对苹果轮纹病菌、苹果斑点落叶病菌和苹果腐烂病菌的最高抑制率分别为59.76％、66.42％和68.33％.说明利用球孢白僵菌开发抗果树病原菌活性物质具有较大的潜力.%To study the antimicrobial activity of Beauveria bassiana against pathogenic fungi of fruit tree,in vitro antagonism of the Beauveria bassiana strain BD-B180 was tested against Valsa mali Miyabe et Yamada,Physalospora piricola Nose,and Alternaria mali Roberts in laboratory.The results showed that B.bassiana BD-B180 had a certain inhibition against the three kinds of pathogenic fungi by confront culture and showed the best inhibition effect on A.mali Roberts.The highest inhibition rate to mycelia growth of A.mali Roberts,P.piricola Nose,and V.mali Miyabe et Yamada by BD-B180 reached 45.08％,41.35％,and 39.74％ respectively.On the PDA plate mixed with BD-B180 conidia suspension,different doses of conidia had different inhibitory effects,with inhibition rate linearly correlated to inoculums.On the PDA plate mixed with 2.49 × 107 cfu/mL of BD-B180 conidia,BD-B180 had the best inhibition effect on P.piricola Nose with the highest inhibition rate of 90.81％,and the highest inhibition rates on A.mali Roberts and V.mali Miyabe et Yamada were 77.14％ and 52.78％ respectively.The sterile fermented broth of BD-B180 also displayed inhibition,with inhibition rate linearly correlated to metabolite concentration.The highest inhibition rates to mycelia growth of P.piricola Nose,A.mali Roberts and V.mali Miyabe et Yamada by BD-B180 fermented broth cultured for 20 d reached 59.76％,66.42％ and 68.33％,respectively.It indicates that developing active substances anti-fruit tree pathogens from B.bassiana has great potential.