中文摘要：

烟草黑胫病是烟草生产中危害最严重的土传病害之一，生物防治具有抗病和环保的作用，获得高效拮抗菌株是进行生物防治研究的基础。本研究采用平板对峙法，在烟草黑胫病发生严重的田块中选取健康烟株，从其根际土壤中分离筛选到12株对烟草黑胫病病原菌Phytophthora parasitica var．nicotianae具有拈抗效果的菌株，抑菌率59．4％～71．1％。选择抑菌率最高的C-5菌株进行试验。经鉴定C-5菌株为多粘类芽孢杆菌（Paenibaci Uuspolymyxa）。抗菌谱试验结果表明：C-5菌株不仅对黑胫病病原菌有较强的拮抗作用，同时对甜瓜、黄瓜枯萎病病原菌和辣椒疫病病原菌也具有拮抗作用。苗期盆栽试验结果表明：利用C-5菌株发酵制备的微生物有机肥能抑制烟草黑胫病的发生，苗期防治率达80％。本文首次报道了多粘类芽胞杆菌菌株对烟草疫霉有拮抗作用。

英文摘要：

Tobacco black shank is one of the most serious soil-borne diseases in tobacco production. Biological control has been proved effective and environment-friendly, but screening of antagonists against pathogens is the basic work in bio-controlling. Twelve strains of bacteria antagonist against Phytophthora parasitica var. nicotianae were isolated by using the plate-confrontation method from rhizosphere soils under healthy tobacco plants in tobacco fields seriously infected with the pathogen. The averaged inhabiting rates of the antagonists ranged from 59.4% to 71. 1%. The best performer Strain C-5, which was identified as Paenibacillus polymyxa （C-5） based on biochemica1 tests and 16S rRNA sequence similarity, was then selected for further experiments. Results from antibiotic spec- trum experiments show that Strain C-5 was also effective in inhibiting other plant pathogen such as Fusarium osypo- runrn f. sp rnelonis , Fusarium osyporum f. sp cucumerinum and P. capsici. Pot experiments show that application of bio-organic fertilizer supplemented with Strain C-5 suppressed the incidence of tobacco black shank by 80% as compared with the control. To our knowledge, this is the first report on the microbiological antagonism of Strain Paenibacillus against Phytophthora parasitica var. nicotianae.