Effects of Different Sources of Armillaria mellea Co-Cultivation on the Quality and Soil Microecology of Gastrodia elata

To investigate the effects of different Armillaria mellea (A. mellea) sources on Gastrodia elata (GE) yield, quality, and soil microecology, five A. mellea of difference sources (M1–M5) were co-cultivated with Zhaotong GE at two sites. M5 co-cultivation produced the highest yields (fresh weight) at both Xiaocaoba, Yiliang (XCB) and Wanchang, Zhenxiong (ZXWC), reaching 3239 g/m2 and 2550 g/m2. For quality, M1 resulted in the highest total gastrodin and parishin content at XCB, while M3 was superior at ZXWC. Post-cultivation, soil pH increased across all treatments. Soil nutrients increased with M1 and M2 at XCB, and with M4 at ZXWC. In GE rhizosphere soil samples, Proteobacteria, Acidobacteria, and Actinobacteria were dominant bacterial phyla, with Proteobacteria abundance decreasing. The dominant fungal phyla were Ascomycota, Basidiomycota, and Mucoromycota; Basidiomycota abundance increased in all soils, while Ascomycota increased only with M1 and M2. M3-treated soils had the highest Gram-negative bacteria abundance, and M1-treated soils were enriched with saprotrophic fungi. This study has several limitations. The conclusions were drawn indirectly with the host (GE) as the focus, and the A. mellea were not identified to clarify potential genetic differences. Future research should integrate fungal omics analyses for a more in-depth investigation.