Diversity of phyllospheric and endophytic culturable microorganisms in Androsace tapete of the Qinghai-Tibetan Plateau

Abstract:

[Background] Androsace tapete is the representative cushion plant species on the Qinghai-Tibetan Plateau, and the phyllospheric and intrafoliar microorganisms are important for this species to adapt to the extreme environment and are also a unique resource. [Objective] To investigate the diversity of phyllospheric and endophytic culturable microorganisms in A. tapete and the differences in the microorganisms between living and dead individuals. [Methods] Phyllospheric and intrafoliar bacteria, yeasts, and filamentous fungi were isolated from A. tapete in three different regions by pure culture, purified, and identified based on 16S rRNA and ITS sequence analysis. [Results] A total of 350 phyllospheric strains (49 species in 22 genera) were identified, with the dominant species of Penicillium sajarovii, and 274 endophytic culturable strains (45 species in 19 genera) were screened out, with the dominant species of Bacillus mycoides. The two shared the dominant Penicillium. The difference in alpha diversity between phyllospheric and intrafoliar microorganisms of A. tapete and between the living and dead individuals was mostly not significant. The communities shared some members, but there was significant spatial heterogeneity in species composition. [Conclusion] There are abundant culturable phyllospheric and intrafoliar microbial resources in A. tapete, and the species composition was remarkably different between living and dead individuals and between different parts of the leaf, and the selection preferences of microorganisms for different environments result in different community patterns. However, the microbial communities from different sources shared a high proportion of strains, and the heterotrophic mode and ecological niche of these shared strains are not fixed. The heterotrophic pattern and the niches of the shared strains are not fixed. They can survive by both symbiosis and saprophytism, and the living space has no clear boundary. The purified strains can be used for the development and utilization of functional strains.