Hyphal connection increases net resource utilization of saprotrophic fungal mycelia by improving local performance: A case study of the cord-forming basidiomycete, Phanerochaete velutina

To identify the functional advantages of hyphal connections in fungal mycelial networks, we evaluated the wood decaying abilities of the mycelia of a saprotrophic basidiomycete, Phanerochaete velutina, in soil dishes with wood baits. The dishes were surrounded by water, allowing the mycelia to access water. Dishes with two or three baits were placed adjacent to or distant from each other, representing the ease of creating hyphal bridges between the two dishes. After 8 months of incubation, the weight loss of the wood bait was significantly larger in the adjacent pairs of dishes compared to the distant pairs. Mycelia in the adjacent dishes had higher chances to access the water and thus increase water content of the wood, which was the primary factor related to wood weight loss. These results suggest that hyphal connections increase decay ability of P. velutina possibly due to water transfer across the mycelial network.