从毛乌素沙地采集的10份土样中共分离到细菌320株,将分离到的细菌菌株与兰花炭疽病病原菌胶胞炭疽菌进行生长对峙试验。初筛获得拮抗菌57株。复筛后得到筛选自毛乌素沙地土壤生物结皮样品的5A5-3对病原菌具有较高的抑菌活性。对其进行形态特征观察和生理生化试验及16S rDNA序列相似性分析,结果表明:菌株5A5-3与Bacillus velezensis标准菌株(CR-502,AY603658)的16S rDNA序列相似度达100%,最终将菌株5A5-3鉴定为Bacillus velezensis。

Rhododendron changii is a monotypic species in China. This study isolated and obtained 10 same mycorrhizal fungi strains from Rhododendron changii and identified them by traditional classification method of morphology in conjunction with 18S rDNA sequence analysis. The results of identification suggest that this mycorrhizal fungi is Meliniomyces variabilis' sibling species.