一株疫病拮抗青霉P.st10菌株的抗菌活性及其对辣椒疫病的盆栽防效

筛选得到一株疫霉菌的拮抗青霉Penicillium striatisporumP.st10。该菌株强烈抑制疫霉菌及核盘菌的菌丝生长。无菌滤液抑制辣椒疫霉孢子囊的形成及孢子囊、游动孢子的萌发,且能杀死菌丝细胞。该菌株在辣椒根际有很强的定殖能力,有机肥对其定殖有增强作用,接种后40d在根际的青霉菌数量,青霉处理为0.76×104cfu/g,而青霉菌肥处理为2.55×104cfu/g。盆栽试验显示:处理7d后,土壤只接种辣椒疫霉对照发病率为93%;同时接种青霉培养滤液和辣椒疫霉处理为16%;接种青霉培养滤液、新鲜菌丝和辣椒疫霉处理为15%。

Antifungal Activity of Penicillium striatisporum Strain P.st10 and Its Inhibition against Pepper Blight Caused by Phytophthora spp

Penicillium striatisporum strain P.st10 was showed to be highly antagonistic against mycelial growth of Phytophthora spp.and Sclerotinia sclerotiorum, while not antagonistic to other tested plant pathogens in plate tests.Investigation of antagonistic mechanism under light microscope showed that the dilution of filtrate from liquid fermentation of the fungus inhibited pathogen by leading to hyphal abnormality,inhibiting germination of spores,and suppressing formation and germination of sporangium of P.capsici.P.striatisporum could colonize in pepper rhizosphere.Organic fertilizer could improve the colonization ability.The rate of pepper blight disease reduced notably when soil was treated with the mycelium of the strain and its filtrate in pot test.