Single-ascospore culture of Morchella sp. M21-48-1 on MA media (left) and ascocarp of M21-48-1, source of the ascospore sample (right). [Image credit: Melissa Cravero]

Morchella sp. M21-48-1

Morchella sp. M21-48-1 was sequenced as part of the DOE-SFA project “Bacterial-Fungal Interactions and Their Role in Soil Functioning” which aims to explore the taxonomic and functional breadth of the fungal microbiome, as well as examine signatures of genome adaptations to a BFI lifestyle. In this project, we are sequencing the genome of fungal species that establish particular interactions with soil bacteria.

True morels (Morchella spp.) are edible mushrooms highly prized worldwide for their unique taste. Harvested in the wild in most countries, this fungus can however be cultivated in crops or indoors, although its culture remains unstable in terms of yields. To produce ascocarps, morels must undergo sexual reproduction. Most of the morel species are heterothallic, but secondary and primary homothallism have also been described (Du and Yang, 2021; Chai et al., 2022). In heterothallic species, only one mating type (MAT1-1 or MAT1-2 idiomorph) is present in each ascospore. In homothallic specimens, a single ascospore contains both mating types and is thus self-fertile.

Morchella sp. M21-48-1 was generated from a single ascospore. This mycelial isolate is part of an important collection originating from morel fruiting bodies sampled in multiple places in Switzerland since 2019, in order to assess for the first-time morel's biodiversity in the country. The whole genome of this single ascospore isolate is used as part of an investigation on sexual reproductive strategies in morels. It also provides important taxonomic information about a putative new Swiss lineage.

References

Du XH, Yang ZL. Mating Systems in True Morels (Morchella). Microbiol Mol Biol Rev. 2021 Aug 18;85(3):e0022020. doi: 10.1128/MMBR.00220-20. Epub 2021 Jul 28.
Chai H, Liu P, Ma Y, Chen W, Tao N, Zhao Y. Organization and Unconventional Integration of the Mating-Type Loci in Morchella Species. J Fungi (Basel). 2022 Jul 19;8(7):746. doi: 10.3390/jof8070746.