甘蔗鞭黑粉菌拮抗菌鉴定及特性研究

Identification and characterization of sugarcane Sporisorium scitamineum antagonists

摘要:

由甘蔗鞭黑粉菌(Sporisorium scitamineum)引起的黑穗病是造成糖料蔗减产的主要病害，筛选环境适应性强、抑菌效果好的拮抗菌是实现该病害有效防控的重要措施。【目的】从蔗田土壤样品中分离鉴定甘蔗鞭黑粉菌拮抗菌株，为高效防控甘蔗黑穗病提供优质生防菌资源。【方法】采用平板对峙法分离筛选拮抗菌株，通过形态学观察、生理生化试验及16S rRNA基因序列分析确定其分类地位，盆栽及田间小区试验相结合，验证菌株对甘蔗黑穗病的防控效果。【结果】获得3株具有明显拮抗效果的细菌，经鉴定GB-3、GH16-3为贝莱斯芽孢杆菌(Bacillus velezensis)，GH16-8为解淀粉芽孢杆菌(Bacillus amyloliquefaciens)，抑菌圈直径分别为(30.00±1.07) mm、(44.00±1.21) mm和(18.00±0.89) mm，抑菌率分别为16.12%、31.92%和5.91%；对黑穗病盆栽防效分别为74.33%、76.57%、69.07%，田间防效分别为20.08%、55.59%、50.08%。3株菌均具有一定的溶磷能力，可耐受极端盐碱环境，对多种植物病原细菌和真菌具有较好的抑制效果，产吲哚乙酸(indole-3-acetic acid,IAA)产量分别为2.12、1.30和1.22 mg/L，施用后甘蔗株高分别提高28.25%、17.09%和23.31%。【结论】GH16-3菌株的环境适应性强，促生效果明显，对甘蔗黑穗病防效较好，具有潜在的应用价值。

Abstract:

Sugarcane smut caused by Sporisorium scitamineum is one of the major diseases affecting the development of China’s sugar industry,and biocontrol is currently the most efficient and safe means,which necessitates the screening of antagonists with strong environmental adaptability and inhibitory effects.[Objective] To isolate and identify the strains with good antagonistic effects against S.scitamineum from soil and provide high-quality biocontrol strain resources for the efficient prevention and control of sugarcane smut.[Methods]The antagonists were isolated by the plate confrontation assay,and their taxonomic status was determined by morphological observation,physiological and biochemical tests,and 16S rRNA gene sequencing.The pot and field experiments were conducted to study the inhibition effects of the antagonists on sugarcane smut.[Results] Three strains of bacteria with significant antagonistic effects were obtained.Strains GB-3 and GH16-3 were identified as Bacillus velezensis and GH16-8 as B.amyloliquefaciens,with the inhibition zone diameters of (30.00±1.07),(44.00±1.21),and (18.00±0.89) mm and the inhibition rates of 16.12%,31.92%,and 5.91%,respectively.The inhibition effects of the three strains against sugarcane smut were 74.33%,76.57%,and 69.07% in pots and 20.08%,55.59%,and 50.08% in fields,respectively.All the three strains had phosphorus-solubilizing ability,tolerance to extreme salt-alkaline environments,and inhibitory effects on a variety of phytopathogenic bacteria and fungi,with the indole-3-acetic acid (IAA) yields of 2.12,1.30,and 1.22 mg/L,respectively.The application of the three strains increased the sugarcane plant height by 28.25%,17.09%,and 23.31%,respectively.[Conclusion] Strain GH16-3 has strong environmental adaptability,growth-promoting effect,and prevention effect against sugarcane smut,demonstrating a promising application prospect.