巨龙竹组培苗污染优势内生菌的分离与鉴定

Isolation and identification of advantaged endophyte in polluted Dendrocalamus sinicus plantlets

【目的】对引起巨龙竹组培苗污染的优势内生菌进行分离与鉴定,为后期巨龙竹组织培养基的优化及预防巨龙竹组织培养过程中内生菌污染提供科学依据。【方法】采用NA培养基分离纯化菌株,然后通过菌体的形态结构观察、生理生化试验及16SrDNA序列同源性分析,对引起巨龙竹组培苗污染的优势内生菌进行鉴定。【结果】引起巨龙竹组培苗污染的优势内生菌为SWFU03菌株,其形态特征及生理生化试验结果与芽孢杆菌属(Bacillus)坚强芽孢杆菌(Bacillusfirmus)的生理生化特征基本相同;16SrDNA序列分析结果表明,菌株SWFU03与坚强芽孢杆菌(GQ903389.1)在同一系统发育分支,其同源性为99.11%。【结论】引起巨龙竹组培苗污染的优势内生菌菌株SWFU03为坚强芽孢杆菌。

【Objective】The advantaged endogenous bacteria, which caused contamination of Dendrocalamus sinicus plantlets, was isolated and identified so as to provide scientific references for optimizing later tissue culture media of Dendrocalamus sinicus and pollution prevention during its tissue culture. 【Method】Using the improved NA culture medium to isolate and identify the strain, the bacterial species were identified by morphology observation, physiological and biochemical tests and the sequence analysis of the 16S rDNA. 【Result】The results from physiological and biochemical tests showed that the morphological characteristics of the strain SWFU03 （advantaged endogenous bacteria） matched the descriptions of Bacillus firmus. The sequence analysis of 16S rDNA indicated that this strain had the same embranchment with the Bacillus firmus XJSL1-10 in the phylogenetic tree with the homology of 99.11%. 【Conclusion】The SWFU01 strain was identified as Bacillus firmus.