以固氮菌和解磷菌筛选拮抗作物病害的细菌组合

用选择性培养基从土壤分离筛选了22 种具有固N或解P能力的细菌，不进行纯化，分组混合接种于15种液体培养基,进行继代培养，每代培养48 h.第12代时,各细菌组合的菌类数目及比例达到稳定状态,共获得15个细菌组合,各组合均含有2～3种细菌.对茄黄萎病病原菌(Verticillium dahliae)、棉花立枯病病原菌(Rhizoctonia solani)和黄瓜角斑病病原菌(Pseudomonas syringae)等9种植物病原菌进行平皿抑菌试验,筛选出7个具有抑菌作用的细菌组合,进一步从植株盆栽试验中筛选出6个有防病作用的组合,其中C₇和C₁₅表现出最明显的抑菌防病效果.C₁₅保持了固N能力,C₄、C₅、C₇、C₉、C₁₄和C₁₅保持了解P能力.结果表明,这是一条可获得具有协同作用的、稳定的多功能生防菌剂的途径.

Screening of mixed crop disease-resistant bacterial inoculants from N2-fixing and P-solubilzing bacterial isolates

In this paper,a total of 22 bacterial isolates capable of fixing nitrogen and/or solubilizing phosphorus were inoculated,and mixed incubated in 15 liquid media.The isolates were obtained from soil with selective media,and not purified.After grown for 48 hours,the mixed cultures were continuously inoculated to the same media,and then incubated under the same conditions.The procedures were repeated for 12 times,and 15 stable bacterial mixtures(SBM) were obtained.Each SBM was purified,which contained two or three bacterial species.Agar plate bacteriostasis test showed that 6 mixed cultures of the SBM exhibited significant inhibition effects to one or more plant pathogens of Verticillium dahliae,Rhizoctonia solani,and Pseudomonas syringae.It was found that C_7 and C_(15) were the two SBM with most obvious antibiological effect.SMB C_(15) had the ability of nitrogen fixation,and C_4,C_5,C_7,C_9,C_(14) and C_(15) showed the ability of phosphorus solubilization.These results suggested a possible approach to develop stable,synergistic,and multi-functional antibiological agents.