Investigation of the Impact of Soil Physicochemical Properties and Microbial Communities on the Successful Cultivation of Morchella in Greenhouses

Morels (Morchella spp.) are medicinal and edible mushrooms, renowned for their distinctive taste and appearance. Due to the low yields and difficulty of foraging wild morels, artificial cultivation has significant economic value. Outdoor cultivation yields are influenced by factors such as weather and diseases, which can result in crop instability or failure, thereby causing losses to farmers. Previous studies have typically concentrated on either the fungal or bacterial communities. In this study, we investigated the ecological relationships between morel growth and both the fungi and bacteria in soil, analyzed over multiple trophic levels. We investigated three soil types: soil in which morel death was observed (DM), soil in which no morels emerged (UM), and soil that is suitable for normal fruiting (NM). We used high-throughput ITS and 16S rDNA amplicon sequencing, alongside assessment of soil physicochemical properties, to investigate factors contributing to morel emergence and death. The results indicated that the richness and diversity of both fungal and bacterial communities in the normal fruiting soil (NM) were significantly higher than those in the non-fruiting soils (DM and UM). The bacterial community was primarily composed of Proteobacteria and Bacteroidota, while the fungal community was dominated by Ascomycota and Mucoromycota. Furthermore, Morchella was significantly enriched in NM, indicating that it had successfully colonized and could develop into fruiting bodies. The morel mycelium in NM effectively utilized external nutrient bags, enhancing the soil nitrogen and organic matter content while reducing the consumption of available phosphorus and potassium. LEfSe and random forest analyses identified Pedobacter and Massilia as biomarkers of NM, potentially associated with the symbiosis of Morchella, which may promote its growth. Furthermore, the construction of the fungal-bacterial co-occurrence network revealed that the NM soil exhibited a higher number of nodes and greater network stability, suggesting that its complex microbial community structure may play a crucial role in the successful cultivation of Morchella. Our results indicate that the failures in morel production were due to inadequate management practices. Elevated greenhouse temperatures may have promoted pathogen proliferation, hindering the effective utilization of external nutrient bags by morel mycelium. Consequently, the mycelium was unable to accumulate nutrients efficiently, leading to the inability of Morchella to fruit or resulting in developmental failures. This study offers valuable insights into the interactions between morel mycelium and soil microorganisms, elucidating the reasons for morel cultivation failure and suggesting strategies for optimizing morel cultivation.