Tuber eburneum and Tuber mujicii: New pine-associated Tuber species from eastern North America

ABSTRACT

The ectomycorrhizal truffle genus Tuber is widespread and diverse. Recent sampling of ascomata, ectomycorrhizal root tips, and environmental sequences has resulted in the identification of many Tuber species that cannot be assigned to described species and require formal description. Using morphological and molecular phylogenetic analysis, we describe two North American Tuber species associated with pines (Pinus spp.). Tuber eburneum, sp. nov., is an early-diverging taxon in the Melanosporum clade that differs substantially from all other taxa in that clade due to its light-colored peridium and gleba, lack of peridial warts, and peridial hairs that are ornamented with small, irregular protrusions. Tuber mujicii, sp. nov., is a whitish truffle species in the Puberulum clade. Although T. mujicii is morphologically similar to many related taxa, it can be distinguished by a combination of characters, including peridium color, spore size, number of ascospores per ascus, and number of reticulations across the spore surface.

KEYWORDS:

• Eastern North America
• ectomycorrhizal fungi
• Pezizales
• truffle
• Tuberaceae
• 2 new taxa

ACKNOWLEDGMENTS

We wish to thank the staff at the University of Florida’s Ordway-Swisher Biological Station for facilitating access to collecting sites; Laurel Kaminsky, Arthur Grupe, and Alija Mujic for their help with the collection and documentation of Tuber mujicii in Florida; Maria Dunlavey and the US Forest Service for facilitating access and granting permission to collect specimens in Nantahala and Pisgah national forests; and Kyle Pursel and the Highlands-Cashiers Land Trust for coordinating permission to collect specimens on their properties. Collections in the Great Smoky Mountains National Park were made under Permit No. GRSM-2021-SCI-2516, and we thank Dr. Brandon Matheny and Rachel Sweeny for providing valuable guidance on collection locations. We also thank Steve Lekwa of the Story County Conservation Board for permission to collect truffles in Story County Parks, and Dr. Jack Horner and staff at the Microscopy and NanoImaging Facility at Iowa State University for facilitating the imaging of T. eburneum. Collections Manager Nicole Reynolds from the FLAS herbarium provided assistance in accessioning herbarium specimens from this study.

DISCLOSURE STATEMENT

No potential conflict of interest was reported by the author(s).

SUPPLEMENTARY MATERIAL

Supplemental data for this article can be accessed on the publisher’s Web site.

Additional information

Funding

This work was supported by a US National Science Foundation grant (DEB-1946445 to M.E.S., R.A.H., and G.B.), a US National Science Foundation Graduate Research Fellowship (no. 2019277707 to B.R.L.), the United States Department of Agriculture National Institute of Food and Agriculture (USDA NIFA) (NIFA 1011527 and Hatch Project 1001991 to R.A.H.), and an Iowa Science Foundation award (ISF no. 13-02 to R.A.H.).