| Abstract Detail
Poster Session Koch, Rachel [1], Wilson, Andrew [2], Aime, M. Catherine [1]. The recent speciation of gasteromycete Guyanagaster necrorhiza suggests endemism. A new genus and species of gasteromycete, Guyanagaster necrorhiza, was discovered in tropical rainforests of Guyana’s Pakaraima Mountains. Phylogenetic analyses indicate that Guyanagaster necrorhiza is most closely related to species in the mushroom-forming genus Armillaria, and specifically to the broadly distributed Neotropical species A. puiggarii, which is also found in the Pakaraima Mountains. Although the Pakaraima Mountains are high in fungal diversity, Guyanagaster is the only known gasteromycete genus thus far thought to be endemic. Molecular clock analyses place the beginning of diversification of Guyanagaster from Armillaria at about 14 million years ago. This relatively recent divergence supports our hypothesis that G. necrorhiza is restricted to the  Guiana Shield in northern South America. This hypothesis is also supported by both population genetics analyses—showing G. necrorhiza has limited spore dispersal capabilities—and certain morphological features such as a gelatinous gleba, which precludes G. necrorhiza from wind dispersal, and the absence of strong odors common to other sequestrate fungi suggest it is not mammal dispersed. These characteristics along with its limited distribution suggest that G. necrorhiza is specifically adapted for this rainforest habitat, but the selective forces behind the gasteroid morphology (dispersal vectors, adaptation to climate, etc.) for this species remain unknown.
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1 - Purdue University, Botany and Plant Pathology, 915 West State Street, West Lafayette, IN, 47907, USA
2 - Chicago Botanic Department, Plant Science and Conservation, 1000 Lake Cook Rd, Glencoe, IL, 60022
Keywords:
Systematics
Gasteromycetes
Guyana.
Presentation Type: Offered Paper - Poster
Session: P3
Location: Lincoln Room/Kellogg Hotel and Conference Center
Date: Monday, June 9th, 2014
Time: 8:00 PM
Number: P3006
Abstract ID:114
Candidate for Awards:Graduate Student Poster Presentation Award |
