Rhizosphere Fungal Communities of Staple Bamboo Species Consumed by Giant Pandas in the Longxi–Hongkou National Nature Reserve, Southern Minshan Mountains

Staple-food bamboos are fundamental to giant panda habitats, with rhizosphere fungi influencing bamboo growth and soil processes. Using Illumina MiSeq high-throughput sequencing, we characterized the rhizosphere fungal communities of four staple-food bamboo species (Chimonobambusa purpurea, Indocalamus longiauritus, Chimonobambusa szechuanensis, and Phyllostachys nidularia) in the Longxi–Hongkou National Nature Reserve, southern Minshan Mountains. Across samples, 13 phyla, 49 classes, 113 orders, 245 families, and 485 genera were detected. Unique fungal operational taxonomic units (OTUs) accounted for 66.83–79.24% of OTUs within bamboo samples, whereas only 14 OTUs (0.50% of the pooled OTU union) were shared by all four species. Fungal diversity and richness varied among hosts, with C. szechuanensis exhibiting the highest Shannon, Simpson, and Chao1 values. Dominant genera also differed among bamboo species: Archaeorhizomyces in I. longiauritus, Cryptococcus in P. nidularia, Tetracladium in C. purpurea, and Lactarius in C. szechuanensis. The high abundance of Mortierella in the rhizosphere of C. purpurea is consistent with certain previously reported plant-beneficial taxa, suggesting potential ecological relevance that warrants further validation; the high abundance of Gibberella in P. nidularia identifies a taxon of interest for subsequent disease monitoring and species-level identification. However, these findings require further verification through cultivation, functional analysis, and pathogenicity tests.