香蕉枯萎病拮抗菌筛选及其抑菌活性

为获得对香蕉枯萎病菌具有稳定拮抗作用的微生物菌株,分别从海南省临高县南宝镇新营农场、皇桐村及美台镇美梅村采集感病土壤和健康土壤进行微生物分离,并以香蕉枯萎病菌4号小种(Fusarium oxysporum f.sp.cubense Race 4)等9种病原菌为靶标菌株,采用平板对峙法和含药介质法对拮抗菌的抑菌活性进行评价,同时根据形态特征、培养特征及生理生化特征和16S rDNA序列分析对其进行鉴定。结果表明:6个土壤样品中共分离得到具有拮抗作用的细菌93株和放线菌133株,其中T3-G-59菌株对9种病原菌具有广谱抗性,菌丝生长抑制率为43.58%~86.43%,孢子萌发抑制率为42.22%~81.11%,其中对香蕉枯萎病菌4号小种的菌丝生长和孢子萌发抑制率分别为86.43%和81.00%,经鉴定该菌株为多产色链霉菌Streptomyces polychromogenes,表明该多产色链霉菌T3-G-59菌株具有应用于香蕉枯萎病生物防治的潜力。

Screening and antibacterial activity of antagonistic bacteria against banana Fusarium wilt disease

In order to obtain the antagonistic strains against Fusarium oxysporum f. sp. cubense of banana, microbial strains from healthy soil and diseased soil in three different places in Hainan Province were separated and screened, and F. oxysporum f. sp. cubense Race 4 and other eight kinds of pathogens were taken as indicative strains to evaluate the antibacterial activity of antagonistic bacteria by using plate confrontation and drug-containing medium methods. The results showed that 93 strains of antagonistic bacteria and 133 strains of actinomycetes were obtained from six soil samples. The strain T3-G-59 had strong and stable control effect to nine kinds of pathogens, with an inhibition rate of 43.58%-86.43% against mycelium growth, and an inhibition rate of 42.22%-81.11% against spore germination, including an inhibition rate of 86.43% and 81.00% against mycelium growth and spore germination of Race 4, respectively. Based on the morphological characteristics, cultural characteristics, physiological and biochemical characteristics, and 16S rDNA sequence analysis, the strain T3-G-59 was identified as Streptomyces polychromogenes. These results indicated that the S. polychromogenes strain could provide new resources for the biological control of banana Fusarium wilt disease.