Abstract:

To investigate the natural germination environment and rhizosphere microbial status of Dendrobium denneanum seedlings in Malipo, high-throughput sequencing was employed to analyze the microbial diversity and community composition differences between the rhizosphere soil of one-year-old seedlings and nearby non-germinated seedling soil. The results indicated that compared to non-germinated Dendrobium denneanum seedling soil, the diversity of bacterial and fungal communities in one-year-old Dendrobium denneanum seedling rhizosphere soil significantly decreased. At the phylum level, Proteobacteria ranked the first in bacterial abundance (SCK: 29.48%, A1: 40.23%), followed by Bacteroidota (SCK: 33.73%, A1: 19.12%), with Acidobacteriota and Planctomycetota occupying the third and fourth positions, respectively. Among fungi, Ascomycota showed the highest abundance (SCK: 45.23%, A1: 37.43%), followed by unclassified Mortierellomycota (SCK: 31.89%, A1: 48.35%), while Ciliophora and Basidiomycota ranked third and fourth. Variation analysis revealed that significant differences were found in microbial community composition between the two soil samples (bacteria: R²=0.900, P=0.001; fungi: R²=0.963, P=0.001). Soil environmental factors such as organic matter, total nitrogen, and Ca exhibited significant correlations with beneficial microbes like Mortierella and Sphingomonas. These findings provide scientific insights for developing microbial resources related to Dendrobium denneanum seed germination and analyzing interactions between orchid plants and microorganisms.

Key words: Dendrobium aurantiacum, natural seedlings, nurturing environment, rhizosphere microorganisms, diversity