植物土传病原菌拮抗细菌的筛选与鉴定

从作物根际土壤中分离到1056株细菌，筛选出7个具有较强拮抗活性的菌株。室内测定对水稻纹枯病菌、辣椒疫病菌、瓜果腐霉、油菜菌核病菌、棉花枯萎病菌、茄根腐病菌、棉花黄萎病菌、番茄青枯病菌、甘蓝黑腐病菌等重要土传病原菌有较强拮抗作用；温室盆栽试验对番茄青枯病表现出较好防效，其中以BOH2和OH11效果较为明显，防效分别为90．9％和86．4％。通过形态观察、生理生化试验和16SrDNA序列分析，确定OH11为产酶溶杆菌。BOH3为荧光假单胞菌，其余5个菌株为不同芽孢杆菌。

Selection and Identification of Antagonistic Bacteria against Soil-borne Plant Pathogens

Totally 1056 bacterial strains were isolated from different plant rhizosphere soils, of which 7 strains showed antibiosis activity to phytopathogenic fungi, such as Rhizoctonia solani, Phytophthora capsici , Pythium aphanidermatum , Sclerotinia sclerotiorum , Fusarium oxysporium f. sp. vasinfectum, Fusarium solani, Verticillium dahliae, Ralstonia solanacearum and Xanthomonas campestris pv. campestris. Green house tests revealed that strain BOH2 and OH11 were most effective on controlling tomato bacterial wilt with the control efficiencies of 90.9% and 86.4%, respectively. Based on the phenotypic characteristics and analysis of the 16S rDNA fragment, OHll was identified as Lysobacter enzymogenes, BOH3 was Pseudomonas fluorescens and others were Bacillus spp.