Decline in Morel Production upon Continuous Cropping Is Related to Changes in Soil Mycobiome

Abstract

The black morel Morchella sextelata (Morchellaceae, Pezizales) is a valuable edible mushroom that can be cultivated on a large scale, but a severe yield decline is observed during continuous cropping. The effect of long-term cropping on soil-borne diseases and the dysbiosis of the microbiome and how these biotic factors affect the morel yield are not well understood. To help fill this knowledge gap, we designed an indoor experiment to investigate the influence of black morel cropping regimes on soil physicochemical properties, richness and distribution of fungal community, and morel primordial production. In this study, we employed rDNA metabarcoding and microbial network analysis to evaluate the effect of non-continuous and continuous cropping regimes on the fungal community during three developmental stages of black morel production, namely, the bare soil mycelium, mushroom conidial, and primordial stages. The results showed that during the first year, M. sextelata mycelium overwhelmed the resident soil fungal community by reducing the alpha diversity and niche breadth of soil fungal patterns by a greater amount compared to the continuous cropping regime, leading to high crop yield of 12.39 ± 6.09/quadrat but less complex soil mycobiome. To sustain continuous cropping, exogenous nutrition bags and morel mycelial spawn were consecutively added to the soil. The additional nutrient input stimulated the growth of fungal saprotrophic decomposers. The degrading activity of soil saprotrophs, including M.sextelata, caused a significant increase in soil nutrient content. This led to an inhibitory effect on the formation of morel primordia, resulting in a sharp decline to 0.29 ± 0.25/quadrat and 0.17 ± 0.24/quadrat, respectively, in the final morel cropping. Our findings provided a dynamic overview of the soil fungal community during morel mushroom production, allowing us to identify beneficial and detrimental fungal taxa in the soil mycobiome involved in morel cultivation. The information acquired from this study can be applied to mitigate the adverse impact of continuous cropping on the yield of black morel.

The cultivation regimes of Morchella sextelata trigger shifts in the community assemblage and ecological traits of soil bacteria

“…Samples were collected at three stages: bare soil (BS), conidial (CD), and fruiting body primordium (PD). All soil preparation, inoculation procedures, and sample collection procedures were performed as previously described by Zhang et al (2023b) . The primordium yield was estimated by counting the number of morel primordia per 6 × 6 cm grid.…”

“…All soil samples were immediately frozen in liquid N and stored at −80°C until further processing. Soil physicochemical characteristics, including soil pH, organic matter content, total N, alkali-hydro N, total phosphorus, available phosphorus, and total potassium, were measured according to previously established protocols ( Zhang et al, 2023b ).…”

“…This increase in nutrient content is attributed to the decomposition of the raw substrate within ENB. Additionally, imbalances within the soil mycobiome have been observed in systems characterized by continuous cropping ( Zhang et al, 2023b ).…”

Dynamics of the soil microbial community associated with Morchella cultivation: diversity, assembly mechanism and yield prediction

“…Pseudomonas species can promote mycelial growth, increase yield, and directly interact with mushrooms during the primordium stage to induce primordium formation (Cho et al, 2003 ; Kim et al, 2008 ; Zarenejad et al, 2012 ). Members of Burkholderiaceae can promote ascocarp growth during the fruiting stage (Zhang Y. et al, 2023 ). However, the soil substrate in cultivated mushrooms transmits potential pathogenic fungal taxa, including Aspergillus, Fusarium, Penicillium , and Trichoderma , leading to a decrease in yield and quality (Lo Cantore and Iacobellis, 2014 ).…”

Effects of exogenous self-made active humic acid manure on physical and chemical properties and soil bacteria of continuous cropping obstacle soil in Capsicum annuum L

“…Soil microbial biomass, diversity, and microbiota play a crucial role in continuous cropping. Changes in soil microorganisms directly affect crop growth (Zhang et al 2023). Research has shown that applying organic manure or crop residue can increase the utilization of carbon sources by soil microorganisms in paddy elds (Tang et al 2020).…”