Assessing local adaptations in a widespread forest fungus by in vitro growth experiments

Abstract

Climate change is altering many aspects of local selection regimes. Which aspects of changing environments causing the strongest selective force, differ widely across species. Strong climatic and topographical heterogeneity makes Norway an ideal area to study the relative importance of environmental factors potentially decisive for local adaptation. The main aim of this study is therefore to investigate to which extent climatic variability and habitat (substrate) requirements lead to evolution of local adaptation in the widespread and ecologically important wood-decay fungus Fomitopsis pinicola. By testing specific hypotheses aimed to evaluate the ability for local adaptation in F. pinicola, this study found that different responses to abiotic factors can be linked to local climate. Further, sporocarps sampled from the two most common hosts, Alnus incana and Picea abies revealed significantly different rate of decay when comparing mass loss of wood chips made from A. incana and P. abies. The relationship between growth and decay was negatively correlated, indicative of an underlying trade-off. Thus, this study suggests that climatic variation and substrate requirements affects the phenotype of F. pinicola.