Intercropping Reduces Morel Yield but Boosts Soil Microbial Diversity

A new study published in BMC Ecology and Evolution reveals that while intercropping morels with herbaceous plants significantly reduces fungal yield, it simultaneously enhances soil microbial diversity and alters the transcriptional profile of the fungus. The research, led by Zihan Gao and colleagues, investigates the ecological mechanisms behind the effects of companion plants on Morchella cultivation, a practice often hindered by continuous cropping obstacles linked to soil degradation. By comparing monoculture systems with intercropping setups involving Poa pratensis and Vicia sativa, the study provides a detailed look at the trade-offs between productivity and ecological health in fungal farming systems.

The study established three distinct cultivation treatments to assess these dynamics: a control group consisting of Morchella monoculture, a treatment intercropped with Poa pratensis, and a treatment intercropped with Vicia sativa. Researchers analyzed soil physicochemical properties, microbial community composition using 16S rRNA and ITS amplicon sequencing, and the fruiting body transcriptomes of the morels via RNA-seq.

The results indicated a clear trade-off between yield and soil ecological conditions. Intercropping reduced Morchella yield by 23.7% in the Vicia sativa treatment and by 36.9% in the Poa pratensis treatment compared to the monoculture control. Despite this reduction in harvestable yield, the intercropping treatments significantly increased soil available potassium and promoted the growth of the companion plants. This suggests that while the fungus competes for resources, the presence of herbaceous plants improves certain soil nutrient availabilities, potentially mitigating some aspects of soil degradation associated with continuous cropping.

Microbial community analysis revealed substantial shifts in the soil microbiota. Intercropping decreased the relative abundance of Ascomycota, a phylum that includes Morchella itself, reducing the fungal abundance to approximately one-quarter of control levels. Conversely, the treatments increased fungal alpha-diversity and enriched specific taxa such as Mortierella and Rhizopus. Bacterial communities also underwent significant changes, with the abundance of Pseudomonas increasing 3.3-fold in the Poa pratensis treatment and 3.8-fold in the Vicia sativa treatment. These shifts indicate that the introduction of herbaceous plants reconfigures the microbial landscape, potentially altering the competitive environment for the morels.

Transcriptomic analysis further illuminated how Morchella responds to these environmental changes. The study identified 572 upregulated differentially expressed genes in the Poa pratensis treatment and 1,090 in the Vicia sativa treatment. Commonly upregulated genes were enriched in Gene Ontology terms related to monocarboxylic acid metabolism, iron ion transport, and carbohydrate binding. Additionally, these genes were associated with KEGG pathways including fructose and mannose metabolism and nitrogen metabolism. Treatment-specific responses included the enrichment of oxidation-reduction processes in the Poa pratensis treatment and symbiont attachment and biofilm formation in the Vicia sativa treatment, suggesting distinct adaptive strategies depending on the companion plant species.

The findings highlight a complex interplay between resource competition and environmental optimization. Although intercropping enhanced soil ecological conditions and microbial functional diversity, it did not translate into yield improvement, pointing to significant ecological trade-offs. The continuous upregulation of genes associated with chromatin assembly and metabolic pathway activation across the treatment gradient suggests that the fungus is actively adapting to the altered soil environment. These insights provide a foundation for understanding host-microbe-plant interactions in fungal cultivation systems, emphasizing the need to balance ecological benefits with productivity outcomes in agricultural practices.

The study underscores the importance of considering both microbial and transcriptomic responses when designing intercropping systems for fungi. By revealing the specific genetic and microbial shifts induced by herbaceous companions, the research offers valuable data for optimizing cultivation strategies.

It demonstrates that the impact of companion plants extends beyond simple resource competition to include complex regulatory responses in the fungus and the soil microbiome.

Subject of Research: Effects of herbaceous intercropping on Morchella yield, soil microbiota, and transcriptomic responses

Article Title: Herbaceous intercropping reshapes soil microbial communities and induces transcriptomic responses in Morchella

Article References: Gao, Z., Song, Q., Yin, W., Li, Y., Fan, C., Wang, L., Qiao, Y., & Liang, J. (2026). Herbaceous intercropping reshapes soil microbial communities and induces transcriptomic responses in Morchella. BMC Ecology and Evolution. https://doi.org/10.1186/s12862-026-02578-w

Image Credits: AI Generated

DOI: 10.1186/s12862-026-02578-w

Keywords: Morchella, Intercropping, Soil Microbiome, Transcriptomics, Fungal Cultivation, Poa pratensis, Vicia sativa, BMC Ecology and Evolution, Herbaceous, reshapes, soil, microbial