Diversity and antibacterial activity of endophytic bacteria in roots and stems of Dendrobium officinale with different cultivation patterns

Abstract:

[Objective] To explore the potential microbial resources and functions, this study analyzed the diversity of endophytic bacteria in the roots and stems of Dendrobium officinale cultivated on trunks and in greenhouses. [Methods] The composition and distribution of the endophytic bacterial community were analyzed by Illumina MiSeq High-throughput sequencing. Meanwhile, the endophytic bacteria were isolated using the traditional culture method and identified by 16S rRNA gene sequence analysis. The Kirby-Bauer test was used for detecting antimicrobial activity. [Results] The results showed that the culture-independent bacteria mainly belonged to Pseudomonas (30.52%), followed by Mycobacterium (10.22%) and Brachybacterium (8.32%). The abundance and diversity of endophytic bacteria of Dendrobium officinale cultivated on trunks were higher than that cultivated in greenhouse. The endophytic bacteria of Dendrobium officinale in root showed more abundance and diversity than in the stems. Bacillus (18.37%) accounted for the highest proportion of the culturable endophytic bacteria, followed by Curtobacterium (8.16%). Meanwhile, 8 strains showed antimicrobial activity against at least one pathogen in this study. [Conclusion] The result demonstrated that there was a huge resource of endophytic bacteria in the Dendrobium officinale. The distribution of the endophytic bacterial community was influenced by the difference of cultivation patterns and tissues. In addition, the strains with antimicrobial activity could be used as biological control of pathogenic bacteria. This study provides a diverse endophytic microbial resource of Dendrobium for further exploring and utilizing.