香蕉枯萎病拮抗内生细菌的分离鉴定及防治效果初探

从抗（耐）枯萎病香蕉品种桂蕉 9 号植株根部分离到一株对香蕉枯萎病致病菌 4 号生理小种（FOC4）平板拮 抗抑制率为 85.7%的内生细菌，命名为 GKT04。形态特征、生理生化特征鉴定及 16S rDNA 和 recA 基因序列比对结果 表明，该菌株为解淀粉芽孢杆菌（Bacillus amyloliquefaciens），GenBank 登录号为 KY328743。盆栽试验表明，经菌株 GKT04 处理的香蕉幼苗 64 d 后病情指数比对照降低了 49.23%。菌株 GKT04 最适生长温度为 30 ℃，最适 pH 为 6.0。 菌株 GKT04 发酵上清液可以明显抑制 FOC4 菌落的生长，对 FOC4 菌落生长抑制率为 33.33%，可使 FOC4 孢子萌发率 降低 71.41%。

Isolation,Identification and Control Effect of Antagonistic Endophytic Bacterium Against Fusarium Wilt

Strain GKT04, an endophytic bacterium with an inhibition rate of 85.7% against FOC4 was isolated from the root of Guijiao 9 with resistance or tolerance to Fusarium wilt. The identification of morphological, physiological and biochemical properties, and sequence homology analysis of 16S rDNA and the gene recA showed that this strain was Bacillus amyloliquefaciens and its GenBank accession number was KY328743. Pot experiments indicated that 64 days after being inoculated Fusarium oxysporum f sp. cubense, the disease index of banana seedlings reduced by 49.23%, compared with the control. The optimum growth temperature and pH was 30 ℃ and 6.0 respectively. The pathogen hyphae with suspension obviously inhibited the mycelia growth and the spore germination of Fusarium oxysporum f.sp. cubense, with an inhibitory rate of 33.33% , which reduced the germination rate of FOC4 spores by 71.41%.