Biodiversity of Tricholoma matsutake (syn. T. nauseosum) and its related species based on repetitive DNA and genomics

Tricholoma matsutake and its related species are ectomycorrhizal Agaricomycetes that produce prized mushrooms collectively called “ matsutake”. These mushrooms are mainly distributed in the Northern Hemisphere. In this review, we describe both the pioneering work and recent advances in our understanding of the distribution and evolution of matsutake, with a special focus on genomic studies. Deoxyribonucleic acid (DNA) sequence analyses revealed that Tricholoma caligatum was the earliest species within this group, followed by Tricholoma fulvocastaneum, the cluster with Tricholoma ilkkae, Tricholoma dulciolens, and Tricholoma bakamatsutake, and finally the cluster with Tricholoma murrillianum, Tricholoma mesoamericanum, Tricholoma anatolicum, and Tricholoma matsutake. Although analyses based on mobile DNAs and whole-genome sequences revealed a similar clustering pattern, there are distinct differences in the distribution of mobile DNAs and genomic structure of Tricholoma bakamatsutake and Tricholoma matsutake. Furthermore, repetitive DNA can be used as markers to distinguish among strains and populations of Tricholoma matsutake from different geographical regions, including identifying dispersals of basidiospores. “Telomere-to-telomere genome sequencing” analyses unearthed that both Tricholoma matsutake and Tricholoma bakamatsutake underwent explosive multiplications of retrotransposons within their genomes but with different mobile DNA elements expanded between them. Contrastingly, the structure of the mating loci between Tricholoma matsutake and Tricholoma bakamatsutake is highly conserved.