玉米茎基腐病生防菌的筛选及应用

Screening and application of bio-control bacterium against corn stalk rot caused by Fusarium graminearum

【目的】拟针对禾谷镰孢进行生防菌的筛选和应用研究,以期为玉米茎基腐病生防菌剂的研制奠定基础。【方法】通过对峙培养法对玉米茎基腐病的主要致病菌禾谷镰孢进行玉米内生生防细菌的筛选,从玉米主栽品种九单48幼苗内部获得一株具有较强抑菌效果的内生生防细菌(简称48SJ7-1);基于传统鉴定、16S rRNA基因序列测定及系统发育分析,对48SJ7-1进行鉴定;并通过盆栽试验测定该生防菌株的防效。【结果】菌株48SJ7-1经鉴定为甲基营养型芽孢杆菌,GenBank登录号为KU377993,48SJ7-1盆栽防效为68.47%,与对照药剂2%戊唑醇悬浮种衣剂差异不显著。【结论】48SJ7-1对玉米茎基腐病的主要致病菌禾谷镰孢有较好防效,对玉米生长还有明显的促进作用,而且表观上无药害发生。

[Objective] To study the screening and application antagonisms of Fusarium graminearum in order to lay the foundation for use of bio-control agents for corn stalk rot. [Methods] The antagonism of F. graminearum were screened from corn endophytic bacteria using the confrontation culture method. A bacterial strain （named as 48SJ7-1） which showed inhibition to F. graminearum was obtained. The bacterial strain was identified according to its physiological and biochemical characteristics and a 16s rRNA gene sequence analysis; and its effect on corn stalk rot caused by F. graminearum was determined by pot experiment. [Results] Strain 48SJ7-1 was identified as Bacillus methylotrophicus （accession no. KU377993）. In pot experiments, application of 48SJ7-1 reduced corn stalk rot by 68.47% compared to the non-treated control, and there was no statistically significant difference with the 2% tebuconazole FSC treated plants. [Conclusion] F. graminearum, the main pathogenic fungi of corn stalk rot, can be effectively controlled by 48SJ7-1. The potting results showed that 48SJ7-1 could promote maize growth and no phytotoxicity was observed.