Library

eCommons

 

FUSARIUM GRAMINEARUM AT THE INTERSECTION OF WHEAT AND WILD GRASS COMMUNITIES

Simple item page
dc.contributor.authorFulcher, Michael
dc.contributor.chairBergstrom, Gary Carlton
dc.contributor.committeeMemberPower, Alison G.
dc.contributor.committeeMemberEvanega, Sarah Nell
dc.date.accessioned2019-10-15T15:30:28Z
dc.date.available2019-12-05T07:00:32Z
dc.date.issued2019-05-30
dc.description.abstractFusarium graminearum poses a significant challenge to the production of staple cereal crops around the world and causes animal and human health risks by contaminating grain with toxin. Primarily understood as an agricultural pathogen, F. graminearum is also associated with dozens of non-cultivated or wild hosts. The pathogen’s relationship with wild hosts is poorly understood and may have an underestimated influence on epidemiology and evolution. This dissertation broadly examined the population biology and ecology of F. graminearum at the interface of wheat and grass communities. A field survey associated pathogen incidence in grasses with cumulative host density and rainfall. Two distinct Fusarium communities differing in diversity and structure were connected to variation in annual and regional environmental conditions. Fusarium graminearum population structure was characterized using microsatellite markers and loci associated with the production of toxin variants. Three sympatric North American populations were present in New York, but in remote, fragmented host communities, extensive admixture was detected between populations with different toxin production profiles. Wild grasses in non-agricultural settings supported a different balance of populations than was found in wheat fields, and even small pockets of wild hosts provided overwintering sites for a large number of diverse isolates. The competency of six common grasses and wheat were contrasted in controlled experiments, and though several grasses were less suitable than wheat during some stages in the pathogen life cycle, the majority were comparable as hosts. Isolates derived from wheat and grasses were phenotyped for fitness related traits and displayed a difference in mean asexual reproductive traits. Conidia length appeared to be under selection, and evidence of a trade-off with mycelial growth was observed. Cumulatively, these studies implicated regional environmental factors as the driving forces behind the epidemiology, community ecology and population structure of F. graminearum, highlighted the potential for inoculum produced on grasses to contribute to crop infections, and suggested wild grasses may play a greater role in promoting pathogen diversity than previously recognized.
dc.identifier.doihttps://doi.org/10.7298/pejv-3t90
dc.identifier.otherFulcher_cornellgrad_0058F_11416
dc.identifier.otherhttp://dissertations.umi.com/cornellgrad:11416
dc.identifier.otherbibid: 11050348
dc.identifier.urihttps://hdl.handle.net/1813/67366
dc.language.isoen_US
dc.subjectdisease ecology
dc.subjectfungal ecology
dc.subjectfungal population biology
dc.subjectFusarium
dc.subjectwild hosts
dc.subjectPlant pathology
dc.titleFUSARIUM GRAMINEARUM AT THE INTERSECTION OF WHEAT AND WILD GRASS COMMUNITIES
dc.typedissertation or thesis
dcterms.licensehttps://hdl.handle.net/1813/59810
thesis.degree.disciplinePlant Pathology and Plant-Microbe Biology
thesis.degree.grantorCornell University
thesis.degree.levelDoctor of Philosophy
thesis.degree.namePh.D., Plant Pathology and Plant-Microbe Biology

Files

Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
Fulcher_cornellgrad_0058F_11416.pdf
Size:
4.24 MB
Format:
Adobe Portable Document Format
Download

Collections

Cornell Theses and Dissertations