芽胞杆菌JK05的鉴定及其对香蕉、玉米的促生和生防潜能研究

解淀粉芽胞杆菌、枯草芽胞杆菌和苏云金芽胞杆菌等是重要的有益微生物,被广泛应用于植物病虫的生物防治。前期分离获得1株芽胞杆菌JK05,对其形态、生理生化特征、16S rRNA和gyrA基因序列进行分析,将其鉴定为解淀粉芽胞杆菌植生亚种Bacillus amyloliquefaciens subsp. plantarum。对峙培养实验结果显示,JK05菌株对多种植物病原镰刀菌具有拮抗作用。植物生长促进实验表明,JK05菌株对香蕉和玉米生长具有明显促进作用。盆栽实验结果显示,JK05菌株对香蕉枯萎病具有良好的防治效果。采用特异引物对JK05菌株基因组DNA进行PCR扩增,其可扩增到表面活性素（surfactin）、丰原素（fengycin）、伊枯草菌素A（iturin A）等抗生素合成基因。综上,JK05菌株具有良好的生防潜力,有望应用于生物农药和微生物肥料。

Identification of Bacillus JK05, Analysis of Its Biocontrol Potential and Roles in Plant Growth Promotion of Banana (Musa spp.) and Maize (Zea mays L.)

Bacillus strains, including Bacillus amyloliquefaciens, B. subtilis and B. thuringiensis, are important beneficial microbes, which have been applied for the biocontrol of plant diseases and pests. We isolated a Bacillus strain named JK05 previously, and it was identified as Bacillus amyloliquefaciens subsp. plantarum based on its morphological characterization, physiological, and biochemical properties as well as 16S rRNA and gyrA gene seqences analysis. The confrontation assay showed that JK05 had antifungal activities against a number of fungal phytopathogens. Plant growth promotion assay revealed that JK05 played roles in promoting plant growth of maize (Zea mays L.) and banana (Musa spp.). The pot assay demonstrated that JK05 possessed a prominent effect on the control of Fusarium wilt of banana caused by F. oxysporum f. sp. cubense. The PCR assay performed using the specific primers for genes related to the antibiotic biosynthesis revealed that the genome of JK05 contained the genes responsible for the synthesis of surfactin, fengycin and iturin A. The results suggested that JK05 had an excellent biocontrol potential, which could be applied as biopesticides and biofertilizers.