巴旦木细菌性穿孔病菌的生物学特性及抑菌药剂筛选

Study on the biological characteristics of the pathogen of bacterial perforation of alternaria alternata in Xinjiang and the screening of laboratory agents

【目的】研究巴旦木细菌性穿孔病病原菌的生物学特性,筛选出室内抑菌效果较好的防控药剂,为病害田间防控药剂的筛选提供理论依据和备选药剂。【方法】供试8种培养基采用紫外分光光度计法,测定病原菌在不同温度、培养基、碳源、氮源、pH和NaCl浓度条件下的生长速率;运用滤纸片抑菌圈法比较12种不同药剂的抑菌效果。【结果】最适病原菌生长的培养基为LB,最适生长温度为28℃,在以甘露醇为碳源和酵母膏为氮源时生长量最好;病原菌在pH为5~10均能生长,最适pH为7.5,致死温度为50℃;在供试的12种药剂中,0.3%四霉素和1.2%的中生菌素抑菌效果最好,EC_(50)分别为2.925、6.474 mg/L,其次是3%噻霉酮和53.8%氢氧化铜,EC_(50)分别为20.245、50.947 mg/L,80%波尔多液和30%噻唑锌对病原菌的抑制效果相对较差,当浓度达到10000 mg/L以上才能抑制病原菌。【结论】6种供试培养基中最适合病原菌生长的为LB培养基,最适合温度为28℃,最适pH为7.5,8种供试碳源中,最适合碳源为甘露醇,8种供试氮源中,最适合氮源为酵母膏,12种供试药剂室内毒力测定表明:0.3%四霉素的毒力最强,其次为1.2%中生菌素和3%噻霉酮,3种防治药剂较好。

【Objective】To clarify the biological characteristics of pathogens of almond bacterial shot hole,and screen out efficient antibacterial agent,so as to provide theoretical basis and alternative agents for the screening of field control agents.【Methods】The results showed that the optimum medium for pathogen growth was LB,among the 8 tested media,the growth rate of pathogens under different temperatures,culture media,carbon and nitrogen source,pH and NaCl concentration was measured by UV spectrophotometer and the antibacterial effects of 12 different selected agents were compared by filter paper bacteriostatic circle method.【Results】The optimum growth temperature was 28℃,and the growth was the best when mannitol was used as carbon source and yeast extract as nitrogen source;the pathogen could grow at pH 5-10.the optimum pH was 7.5 and the lethal temperature was 50℃;the toxicity test showed that 0.3%tetramycin and 1.2% mesobiotic had the best antibacterial effect,with EC_(50) of 2.925 and 6.474 mg/L respectively,followed by 3% thiamycin and 53.8% copper hydroxide,EC_(50) of 20.245 and 50.947 mg/L respectively,and 80% Bordeaux solution and 30% thiazole zinc had relatively poor inhibitory effect on pathogenic bacteria.When the concentration reached more than 10,000 mg/L,the pathogen could be inhibited among the 12 agents.【Conclusion】Among the six tested mediums,LB medium is the most suitable for the growth of pathogens,with the most suitable temperature at 28℃ and the most suitable pH of 7.5.Mannitol is the most suitable carbon source among the 8 tested carbon sources,and yeast extract is the most suitable nitrogen source among the 8 tested nitrogen sources.The indoor toxicity test of 12 tested reagents shows that 0.3%tetramycin has the strongest toxicity,followed by 1.2% mesobiotic and 3% thiamycin.