Authors: Joshua Stubbs, Annette Lewis, Kendall Holcomb, Barbara Suassuna Schincariol
Mentors: Geoffery Zhan
Insitution: Utah Valley University
Does Greater Phylogenetic Distance Affect Competition Outcomes in Fungal Communities?
Annette Lewis, Kendall Holcomb, Bárbara Suassuna Schincariol, Josh Stubbs, Geoffery Zahn PhD
Fungi play a critical role in decomposition, affecting nutrient cycling at a global scale. Saprotrophic fungi competitively decompose dead organic matter. However, the role of phylogenetic relatedness on interspecific competition in fungal communities has not received much attention. The theory of phylogenetic over-dispersion suggests that species within a community tend to be less related than expected by chance, therefore limiting competition due to functional redundancy. Similarly, Darwin’s naturalization hypothesis suggests that taxonomically distinct invaders might experience reduced competition and resistance. In this study, we chose three different saprotrophic fungal species with varying relatedness: Aspergillus niger and Fusarium keratoplasticum (from the same family), and Pleurotus ostreatus (from a different phylum). These species were chosen based on decomposition abilities and phylogenetic distances. These species were cultured and placed in seven combinations to assess their ability to decompose and compete as individual fungal populations and as combined communities (e.g., A, B, A+B, B+C, and A+B+C). Each species was placed near a sterilized piece of paper such that competition was evaluated by analyzing the paper coverage in Petri dishes over three weeks. Each Petri dish was analyzed individually based on the average percentage of paper covered and, within combined communities, the percentage of paper each species covered. Interactions between each species and the percentage of the paper covered was recorded for further analysis. Assessing paper coverage allows for the observation of any potential competitive inhibition of decomposition. We hypothesize that decomposing and competitive abilities would be the strongest with A. niger. Despite the fast growth rate of A. niger individually, preliminary results suggest that it was outcompeted when paired with other species. This research highlights the potential nuances in fungal community interactions influenced by phylogenetic relationships, shedding light on the principles of phylogenetic overdispersion and Darwin’s naturalization hypothesis.