山东省保护地土壤黄瓜菌核病拮抗细菌的分离与鉴定

Isolation and Identification of Antagonistic Bacteria Against Sclerotinia sclerrotium (Lib)de bary from Greenhouse Soil in Shandong,China

利用点接法从山东省9个地市的保护地黄瓜菌核病病株根际土壤中初步筛选到21株拮抗细菌,其分布率与田间发病率呈正相关,经平板对峙培养复筛出4株对黄瓜菌核病菌具有强烈抑制作用的细菌。该4个菌株均具有明显的抑菌宽带,其中菌株BSH-4对黄瓜菌核病菌的抑制率最高为91.1%,抑菌带宽度为18.5mm;4个菌株对黄瓜猝倒病菌、蔓枯病菌、枯萎病菌和立枯病菌,番茄早疫病菌、辣椒疫病病菌、茄子绵疫病菌等7种常见蔬菜土传病害的致病菌均表现出不同程度的抑制作用。根据菌株的菌体形态、培养性状、生理生化特性等指标,初步确定4菌株中1株为多粘类芽孢杆菌(Paenibacillus polymyxa),1株为枯草芽孢杆菌(Bacillus subtilis),2株为短小芽孢杆菌(Bacillus pumilus)。

21 strains of antagonistic bacteria were isolated from the rhizosphere soil of cucumber infected by S. sclerrotium （Lib）de bary in sheltered field in 9 districts of Shandong province, China. There was a positive relationship between the disease severity and the quantity of antagonistic bacteria. In dual culture test, the four strains of BL01, BL02, BSH-4 and ZB13 showed strong inhibition ofS. sclerrotium. In addition, the visible inhibition zone indicated that they inhibited the pathogenic fungi by producing active substances. BSH-4 had the strongest inhibition, with the inhibition rate up to 91.1%, and its inhibition zone was 18.5 mm. All the 4 strains showed a broadly antagonistic spectrum and activity against 7 pathogens such as Pythium spp, Didymella bryoniae, Fusarium oxysporum, Rhizoctonia solani, A lternaria solanl, Phytophthora capsici and Phytophthora parasitica. According to their morphological, physiological and biochemical characteristics, the four active strains were identified, and BL01 was Paenibacillus polymyxa, BL02 was Bacillus subtilis, both BSH-4 and ZB13 were Bacillus pumilus.