Mycological Progress

, Volume 17, Issue 1–2, pp 45–63 | Cite as

An ultrastructural study of spore wall development and septal pores in species of the Pachyphlodes (Pezizaceae, Pezizales) lineage, with a description of the new species Pachyphlodes annagardnerae

  • R. A. Healy
  • H. T. Horner
  • G. Bonito
  • D. J. McLaughlin
  • M. E. Smith
Original Article


Pachyphlodes (Pezizaceae) is a genus of truffle-like fungi that is distributed across the Northern Hemisphere. These fungi form ectomycorrhizae primarily with trees in the Fagaceae family, and occasionally with other host plants. The genus Plicariella (= Scabropezia) is phylogenetically inferred as an ally of, or within, the Pachyphlodes lineage. Despite molecular phylogenetic analyses that show the close relationships of species in these two genera, morphological differences in ascomata shape and color, spore ornamentation, and ascus shape are profound. Here, we studied spore wall development to better understand affinities within the PachyphlodesPlicariella lineages. Electron microscopy studies indicate that the initial spore wall development is similar across six Pachyphlodes species and a Plicariella species, despite striking differences in mature spore ornamentation among species. Ultrastructural analyses reveal that differences in spore ornamentation among Pachyphlodes species are due to unique developmental events at the final stages of spore wall deposition. Septal pore ultrastructure in Pachyphlodes species is similar to other Pezizaceae that have been studied. Molecular analyses of the five species studied indicate that four of them have not been previously described. The new species Pachyphlodes annagardnerae is here described, and the ultrastructural features of species of Pachyphlodes, Plicariella, and other Pezizales are compared and discussed.


Ascospore development Truffle-like fungi Pachyphloeus Plicariella Septa Taxonomy 



We thank the following herbaria and their curators for specimen loans that were instrumental to this study: BG, CUP, FH, K, MA, NY, OSC, S, and SOC. The FLAS herbarium provided critical support for this work. Richard Kay generously translated the Latin description of P. ligericus. The following people contributed specimens and samples that were used in this study: Julio Cabero, Michael Castellano, Efren Cázares, Aurelia Paz Conde, Roy Halling, Carol Hobart, Debbie Klein, Alicia Knudson, Esther McLaughlin, Jean-Baptiste Perez, Branislav Peric, Lois H. Tiffany, and Nicolas Van Vooren. Lois Tiffany was a valued mentor for the ultrastructural portion of this project. Funding for RAH came from the Gilman Fund at Iowa State University, the Iowa Science Foundation, the Iowa Department of Natural Resources, the Minnesota Department of Natural Resources, The Society of Systematic Biologists, and The University of Minnesota Doctoral Dissertation Fellowship. Funding for MES was provided by NSF grant DEB-1354802, with additional support from the Institute for Food and Agricultural Sciences (IFAS) at the University of Florida.


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Copyright information

© German Mycological Society and Springer-Verlag GmbH Germany 2017

Authors and Affiliations

  1. 1.Department of Plant Pathology, Fifield HallUniversity of FloridaGainesvilleUSA
  2. 2.Department of Genetics, Development and Cell Biology, Bessey HallIowa State UniversityAmesUSA
  3. 3.Department of Plant, Molecular Plant Sciences BuildingMichigan State UniversityEast LansingUSA
  4. 4.Department of Plant BiologyUniversity of MinnesotaSt. PaulUSA

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