【摘要】 为了研制出有效的黄芪根腐病生物防治产品,本研究利用从疏勒河流域盐碱土壤中分离出对其致病菌有良好防治作用的放线菌进行多菌复配,以期提高生防菌对黄芪根腐病的防效。采用平板对峙法和生长速率法筛选高效生防菌,并对其进行形态特征、生理生化和16S rRNA基因序列鉴定,并采用盆栽试验对黄芪根腐病的防治效果进行测试。结果表明:从供试的244株放线菌中,经初筛有11株放线菌对黄芪根腐病菌的抑菌率均高于50%,复筛后对黄芪根腐病菌的抑菌率为7%～57%。结合筛选效果和菌株间亲和性试验,将菌株DA4-3-12、DA8-4-10和221作为复合菌的研究对象。经鉴定,菌株DA4-3-12和221为Streptomyces alboflavus,DA8-4-10为Streptomyces alanosinicus。单一菌株DA4-3-12、DA8-4-10和221及其不同组合混合菌株(DA4-3-12+DA8-4-10、DA4-3-12+221、DA8-4-10+221、DA4-3-12+DA8-4-10+221)对黄芪根腐病均有防治效果,其防效分别为60%、46%、70%、55%、70%、64%、72%,以混合菌株DA4-3-12+DA8-4-10+221的效果最为理想,混合菌株中各菌株间通过协同作用充分发挥其生防效果,且抑菌谱较广。更多还原

【Abstract】 To develop effective biocontrol products for controlling the root rot of Astragalus membranaceus,actinomycete strains with excellent prevention and controlling effects to pathogenic bacteria were isolated from the saline-alkali soil of Shule River basin,which were further combined into compound agents to improve the anti-bacterial effect on root rot of A. membranaceus.The plate-to-limulus method and growth rate method were used to screen high-efficiency biocontrol actinomycete strains. Morphological characteristics,physiological and biochemical characteristics,and 16 S rRNA DNA sequence analysis were used to identify strains. After that,a pot experiment was conducted to test the controlling effect on root rot of A. membranaceus. The results showed that among the total 244 tested strains of actinomycetes,11 strains had inhibitory rates of more than 50% against the root rot disease. After rescreening,the inhibitory rate was 7%-57%.Combined with the screening effect and the inter-strain affinity test,the strains DA4-3-12,DA8-4-10 and 221 were used as the research targets for the compound strains. The strains DA4-3-12 and 221 were identified as Streptomyces alboflavus and strain DA8-4-10 as Streptomyces alanosinicus. Single strains DA4-3-12,DA8-4-10 and 221 and their compound strains in different combinations( DA4-3-12 + DA8-4-10,DA4-3-12 + 221,DA8-4-10 + 221,DA4-3-12 + DA8-4-10 +221) all had controlling effects on root rot of A. membranaceus,and their control efficiencies were 60%,46%,70%,55%,70%,64%,and 72% respectively. Among them,the compound DA4-3-12+DA8-4-10+221 had the best controlling effect. The synergistic effects of various strains in the mixed strains were fully expressed,with wide antimicrobial spectrum.更多还原