香蕉炭疽菌拮抗菌HSL3-29的分离鉴定及防治效果

Isolation, identification, and biocontrol effect of a bacterial strain HSL3-29 against Colletotrichum musae

摘要:

【背景】香蕉炭疽病是由香蕉炭疽菌(Colletotrichum musae)侵染引起的真菌性病害，严重制约香蕉产业的发展。【目的】从广西壮族自治区红树林土样中筛选出对香蕉炭疽病有拮抗效果的生防细菌，并评价发酵液的防治效果。【方法】采用平板稀释法分离菌株，以Colletotrichum musae为指示菌，利用平板对峙法筛选具有拮抗效果的菌株；通过形态特征、生理生化特征及16S rRNA基因序列分析确定其分类地位；采用单因素控制法研究其生物学特性；对峙生长法评价其生物活性；离体法测定其发酵液的防效。【结果】筛选获得一株对香蕉炭疽菌具有较强拮抗效果的菌株HSL3-29，其皿内抑制活性为81.83%，并且对其他6种病原真菌具有不同程度的抑制作用，抗菌谱较广。根据该菌的形态特征、生理生化特征及16S rRNA基因序列分析，初步鉴定菌株HSL3-29为Bacillus amyloliquefaciens。该菌株的对数生长期为4−24 h；对氨苄青霉素和万古霉素敏感；具有显著的耐高温能力，并且在高盐的环境中仍能存活。发酵液对香蕉炭疽病的防控效果为39.4%。【结论】分离筛选到一株对香蕉炭疽菌有拮抗活性的细菌，为进一步开发香蕉炭疽病的生防菌剂提供了菌种资源。

Abstract:

[Background] Banana anthracnose is a fungal disease caused by Colletotrichum musae, which seriously restricts the development of the banana industry. [Objective] To screen the biocontrol bacteria against Colletotrichum musae from mangrove soil samples in Guangxi Zhuang Autonomous Region, and evaluate the biocontrol effect of the fermentation broth. [Methods] The biocontrol bacteria were isolated by dilution plate method, and a plate confrontation experiment was conducted to screen out the strains with antagonistic effects on C. musae. The bacterial strain was identified based on morphological characteristics, physiological and biochemical properties, and 16S rRNA sequencing results. The biological characteristics of the strain screened out were studied by single factor experiments. The antagonistic activity was evaluated based on the mycelial growth rate. The biocontrol effect of the fermentation broth was examined with detached banana. [Results] A strain HSL3-29 was isolated from mangrove soil. It had a strong antagonistic effect against C. musae, with the inhibition rate of 81.83%. HSL3-29 had a broad antimicrobial spectrum, with inhibitory effects on other six plant pathogenic fungal species. HSL3-29 was identified as Bacillus amyloliquefaciens. The strain entered the logarithmic growth stage during 4–24 h. It was sensitive to ampicillin and vancomycin, had tolerance to high temperatures, and could survive in high salt environments. The fermentation broth of the strain showed the biocontrol effect up to 39.4% on the banana fruits infected with anthracnose. [Conclusion] A strain of B. amyloliquefaciens with strong antagonism to C. musae was isolated, which provided strain resources for the development of biocontrol agents for banana anthracnose.