野生大豆内生芽孢杆菌BHL3501的鉴定及对大豆胞囊线虫的抑制作用

目的]鉴定野生大豆内生芽孢杆菌BHL3501并研究其对大豆胞囊线虫的抑制作用。方法]通过形态学特征、生理生化特征及16S rDNA分析,鉴定了从野生大豆根中分离筛选到的1株具有杀线虫活力的内生细菌BHL3501,并研究了BHL3501菌株代谢物不同倍数稀释液对大豆胞囊线虫卵孵化及2龄幼虫活力的影响。结果]BHL3501菌株初步鉴定为芽孢杆菌Bacillus sp.。其发酵原液处理24h后对大豆胞囊线虫卵孵化的相对抑制率为98.3%;10倍稀释液处理下相对抑制率为79.5%,均与无菌水对照差异显著。发酵原液处理24 h后,2龄幼虫的校正死亡率为93.1%,各稀释浓度处理均与无菌水对照差异显著。结论]BHL3501代谢物对大豆胞囊线虫卵孵化有强烈的抑制作用,对其2龄幼虫有较强的毒杀作用。

Identification of Endophytic Bacillus BHL3501 from Wild Soybean and its Inhibitory Effect against Soybean Cyst Nematode

Objective] The paper was to identify endophytic bacillus BHL3501 from wild soybean and its inhibitory effect against soybean cyst nematode.Method] Through morphological characteristic,physiological and biochemical characteristics,and 16S rDNA analysis,a strain of endophytic bacteria BHL3501 with nematicidal activity isolated and screened from the root of wild soybean was identified,the effects of BHL3501 metabolite solutions with different dilution multiples on egg hatching and activity of 2nd instar juvenile of soybean cyst nematode were also studied.Result] BHL3501 strain was preliminarily identified to be Bacillus sp..The relative inhibition rate of its original fermentation broth on egg hatching of soybean cyst nematode after 24 h was 98.3%;the relative inhibition rate under 10-time diluted solution treatment was 79.5%,which had significant difference with sterile water control.The correct mortality rate of 2nd instar juvenile was 93.1% after treated by original fermentation broth for 24 h,the treatments of all diluted solutions had significant difference with sterile water control.Conclusion] BHL3501 metabolites had strong inhibitory effect against egg hatching of soybean cyst nematode,which also had strong toxic effect against its 2nd instar juvenile.