Purdue University Graduate School
Browse

New species and records of Xylariaceae and their allies from Guyana with emphasis on elucidating the biology and ecology of Xylaria karyophthora, a putative pathogen of Greenheart (Chlorocardium spp.) seeds

Download (3.97 MB)
thesis
posted on 2024-10-21, 00:10 authored by Dillon R HusbandsDillon R Husbands

 Over the last two decades, mycoflorostic studies undertaken in Guyanese forests have uncovered hundreds of new fungal species and genera. One of the recovered fungal families was the Xylariaceae, although most were not identified to species. Members of this family play ecological roles as decomposers, endophytes, and pathogens of vascular plants and grass species.  In addition, this group is increasingly recognized as a significant source of novel metabolic products with potential for applications in medicine, agriculture, and industrial biofuel. Given its  potential, we took a more targeted approach to the documentation of this group. Our sampling  efforts drawing on more than two decades of field collections yielded ca. 90 species in 12 genera, including a putative pathogen, Xylaria karyophthora of the seeds of Chlorocardium spp (Greenheart). Despite the significance of Greenheart to the Guyanese economy, little is known  about the biology and ecology of this fungus. Due to the lack of available resources to study this  fungus, our objectives were two-fold: first, to sequence and annotate the genome of X.  karyophthora to provide a resource for genome-centric explorations, and to use this genome to  infer the biology and ecology of this fungus. We focused on identifying and characterizing  secretomes, viz. carbohydrate-active enzymes (CAZymes) and secondary metabolites  biosynthetic gene clusters (SMBGCs) to infer the nutritional strategy of this fungus. Our results  suggest that X. karyophthora has the capacity to act as both an endophyte and a pathogen. To  make further inferences about the population, we used SSR markers to elucidate the genetic  diversity and population structure of X. karyophthora. X. karyophthora populations have high  genetic diversity, potentially exploiting both outcrossing and inbreeding reproductive strategies, and demonstrate a pattern consistent with human-mediated spread. This work will contribute  information on new species and records of Xylariaceous fungi and their allies from Guyana with  particular emphasis on unraveling the epidemiology, genetic diversity, and population structure  of X. karyophthora 

History

Degree Type

  • Doctor of Philosophy

Department

  • Botany and Plant Pathology

Campus location

  • West Lafayette

Advisor/Supervisor/Committee Chair

M. Catherine Aime

Additional Committee Member 2

Christian D. Cruz

Additional Committee Member 3

Stephen B. Goodwin

Additional Committee Member 4

Matthew A. Smith

Usage metrics

    Categories

    Licence

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC