Species of Russula from a drumlin archipelago in the northeastern USA

Background

Since December 2012, a fungal inventory has been conducted at the Boston Harbor Islands National Park Area (BHI), the only drumlin archipelago in the USA (Haelewaters et al. 2018). This documentation resulted in over 900 collections, of which 313 have been identified to species level, accounting for 172 species. For identification, DNA was isolated from rice grain-sized pieces of fruiting bodies and sequenced the internal transcribed spacer (ITS) “barcode” region of the ribosomal DNA.

Problem

The genus Russula (Fungi, Basidiomycota, Agaricomycetes) is composed of 750 species, of which 334 species are reported from the USA. Because of their interrelationships with woody plants and mycophagous fauna, Russula species are important components of woodland ecosystems. Unfortunately, many taxa are poorly known, due to short, incomplete diagnoses of taxa; the lack of extensive studies of the genus Russula in North America; and the lack of molecular data. In addition, through both legacy taxonomic assignment and common misidentification, many sequences from North America are mislabeled as European species.

Goals

The goals of this master’s project are: (1) to provide detailed data on species of the genus Russula at the BHI; (2) to record information about their distribution, habitat, and dates of fruiting; and (3) to provide documentation for these species via voucher specimens that will be deposited at the Farlow Herbarium. To date, 40 collections of Russula have been sampled at BHI, of which 11 are identified to species level, good for 7 species. Interestingly, the ITS sequences of a majority of these Russula collections are <97% similar to any Russula sequence available in NCBI GenBank, suggesting that we could be dealing with either undescribed species or species that have been described but never sequenced. This master’s project is necessary for accurate identification of BHI collections for which the ITS sequence is <97% similar to any Russula sequence, including comparison with existing description and types as well as multi-locus sequencing for phylogenetic placement.

References

Adamčík S, Looney B, Caboň M, Jančovičová S, Adamčíková K, Avis PG, Barajas M, Bhatt RP, Corrales A, Das K, Hampe F, Ghosh A, Gates G, Kälviäinen V, Khalid AN, Kiran M, De Lange R, Lee H, Lim YW, Kong A, Manz C, Ovrebo C, Saba M, Taipale T, Verbeken A, Wisitrassameewong K, Buyck B. 2019. The quest for a globally comprehensible Russula language. Fungal Diversity 99: 369-449. https://doi.org/10.1007/s13225-019-00437-2

Buyck B, Jančovičová S, Adamčík S. 2015. The study of Russula in the western United States. Cryptogamie, Mycologie 36(2): 193-211. https://doi.org/10.7872/crym/v36.iss2.2015.193

Haelewaters D, Dirks AC, Kappler LA, Quijada L, Vandegrift R, Buyck B, Pfister DH. 2018. A preliminary checklist of fungi at the Boston Harbor Islands. Northeastern Naturalist 25(Special Issue 9): 45-76. https://doi.org/10.1656/045.025.s904 [pdf]

Looney BP. 2014. Molecular annotation of type specimens of Russula species described by W.A. Murrill from the southeast United States. Mycotaxon 129(2): 255-268. https://doi.org/10.5248/129.255 [pdf]