Evidence that the gemmae of Papulaspora sepedonioides are neotenous perithecia in the Melanosporales

• Author(s) / Creator(s)

  • Tsuneda, A.
  • Davey, M.L.
  • Currah, R.S.

• Papulaspora sepedonioides produces large multicellular gemmae with several, thick-walled central cells enclosed within a sheath of smaller thinwalled cells. Phylogenetic analysis of the large subunit rDNA indicates P. sepedonioides has affinities to the Melanosporales (Hypocreomycetidae). The development of gemmae in P. sepedonioides was characterized by light and scanning and transmission electron microscopy and was similar to previous ontogenetic studies of ascoma development in the Melanosporales. However instead of giving rise to ascogenous tissues the central cells of the incipient gemma became darkly pigmented, thick walled and filled with lipid globules while the contents of the sheath cells autolysed, leaving them empty and deflated at maturity. Both central cells and pre-autolytic sheath cells produced both germ tubes and new gemmae primordia, suggesting microcyclic conidiogenesis occurs in this species. Mature gemmae were nondeciduous or seceded by schizolytic secession and appear to have both perennating and disseminative potential. The evolution of these neotenous perithecial propagules may be driven by life-history and ecological factors selecting for functional versatility.

• Date created

  2008

• Subjects / Keywords

  • Ultrastructure
  • Boreal fungus
  • Microcyclic conidiogenesis
  • Papulospore
  • Aborted ascoma
  • Ascoma development
  • Conidium development

• Type of Item

  Article (Published)

• DOI

  https://doi.org/10.7939/R3P27D

• License

  Copyright 2008 by The Mycological Society of America, Lawrence, KS 66044-8897