Search for: All records

Auricularia auricula-judae is a saprobic European jelly fungus with traditional culinary and medicinal significance, often said to resemble a human ear. It was originally named Tremella auricula by Linnaeus and has been moved to different genera since, but its specific epithet was also changed from auricula to auricula-judae by Bulliard in 1789, which is not normally a valid nomenclatural alteration. However, due to the practice of name sanctioning in the mycological nomenclatural code, this change has been accepted. This article outlines the nomenclatural and cultural history of the controversial name Auricularia auricula-judae and suggests its return to the original specific epithet auricula, as well as the designation of an epitype specimen. 

Fungus-farming ants cultivate multiple lineages of fungi for food, but, because fungal cultivar relationships are largely unresolved, the history of fungus-ant coevolution remains poorly known. We designed probes targeting >2000 gene regions to generate a dated evolutionary tree for 475 fungi and combined it with a similarly generated tree for 276 ants. We found that fungus-ant agriculture originated ~66 million years ago when the end-of-Cretaceous asteroid impact temporarily interrupted photosynthesis, causing global mass extinctions but favoring the proliferation of fungi. Subsequently, ~27 million years ago, one ancestral fungal cultivar population became domesticated, i.e., obligately mutualistic, when seasonally dry habitats expanded in South America, likely isolating the cultivar population from its free-living, wet forest–dwelling conspecifics. By revealing these and other major transitions in fungus-ant coevolution, our results clarify the historical processes that shaped a model system for nonhuman agriculture. 

Summary In the hyperdiverse fungi, the process of speciation is virtually unknown, including for the > 20 000 species of ectomycorrhizal mutualists. To understand this process, we investigated patterns of genome‐wide differentiation in the ectomycorrhizal porcini mushroom, Boletus edulis , a globally distributed species complex with broad ecological amplitude. By whole‐genome sequencing 160 individuals from across the Northern Hemisphere, we genotyped 792 923 single nucleotide polymorphisms to characterize patterns of genome‐wide differentiation and to identify the adaptive processes shaping global population structure. We show that B. edulis exhibits contrasting patterns of genomic divergence between continents, with multiple lineages present across North America, while a single lineage dominates Europe. These geographical lineages are inferred to have diverged 1.62–2.66 million years ago, during a period of climatic upheaval and the onset of glaciation in the Pliocene–Pleistocene boundary. High levels of genomic differentiation were observed among lineages despite evidence of substantial and ongoing introgression. Genome scans, demographic inference, and ecological niche models suggest that genomic differentiation is maintained by environmental adaptation, not physical isolation. Our study uncovers striking patterns of genome‐wide differentiation on a global scale and emphasizes the importance of local adaptation and ecologically mediated divergence, rather than prezygotic barriers such as allopatry or genomic incompatibility, in fungal population differentiation.