Abstract Detail

Mycological Section

Kielsmeier-Cook, Joshua [1], Toapanta, Cristina E. [2], Ordonez, Maria E. [2], Blanchette, Robert A. [3].

Amazonian Xylariaceous fungi: exploring the diversity of an important group of tropical decomposers.

Fungi are one of the most species-rich groups of organisms on the globe and recent work indicates that the vast majority of fungal species remain undescribed. In contrast to the rich history of mycological research in temperate latitudes, ecosystems known to host global maxima of species diversity, i.e. tropical forests of the Neotropics, lack basic foundational investigations. Neotropical forests represent approximately 20% of the globe's remaining forest cover and are important components of the global carbon, water, and oxygen cycles. Fungi are critical components of these ecosystems, recycling the vast majority of organic material bound in leaf litter and woody material. Yasuní National Park, located in eastern Ecuador, is one of the globe's most diverse locations harboring greater angiosperm tree diversity in one hectare than all of North America. Our investigation of 150 collections of Ascomycota made at Yasuní Research Station, operated by the Pontificia Universidad Católica del Ecuador, has focused on Xylariaceous fungi as dominant components of the mycoflora involved in decomposition. For all samples, a portion of the fruit body was preserved in a saturated saline solution containing 20% DMSO until DNA extractions could be performed. Culturing onto MEA + antibiotics was also attempted for all samples and collections were dried and deposited in the collaborating herbarium. A phylogenetic analysis of 78 Xylaria species was conducted via a concordant multi-gene approach using sequences of the α-actin, β-tubulin, and RPB2 genes. Multiple sequence alignments for each gene was conducted in Clustal Omega v. 1.2.1, model selection was performed in jModelTest v. 2.1.7, and a Bayesian phylogenetic analysis was performed in MrBayes v. 3.2.2. The results of this analysis indicate that the 78 samples cluster into 34 species hypotheses (SH) as defined by >97% ITS sequence identity. Of these 34 SHs, only 13 SHs clustered with named Xylaria species. The remaining 21 SHs may represent sequences from previously described but unsequenced species or may represent new species. Current work is underway to morphologically characterize these SHs and deduce their relationships with published Xylaria epithets. This research will serve to increase our understanding of the taxonomy of this important genus in tropical rainforests and provide new information on their role as endophytes, saprotrophs, and symbionts within this species-rich ecosystem.

1 - University of Minnesota, Plant Pathology, 495 Borlaug Hall, 1991 Upper Buford Circle, St. Paul, MN, 55108, USA
2 - Pontificia Universidad Catolica del Ecuador, School of Biological Sciences, Av. 12 octubre 1076, Quito, Ecuador
3 - University of Minnesota, Department of Plant Pathology, 1991 Upper Buford Circle, 495 Borlaug Hall, Department of Plant Pathology, St. Paul, MN, 55108, United States

Keywords:
Xylaria
Fungi
Amazon
Fungal phylogeny
Ecuador
biodiversity
wood decay fungi
Ascomycota.

Presentation Type: Oral Paper:Papers for Sections
Session: 67
Location: Salon 1/The Shaw Conference Centre
Date: Wednesday, July 29th, 2015
Time: 3:00 PM
Number: 67007
Abstract ID:581
Candidate for Awards:MSA Best Oral Presentation Award by a Graduate Student