Degree Name

MS (Master of Science)

Program

Biology

Date of Award

8-2013

Committee Chair or Co-Chairs

Foster Levy

Committee Members

Jamey Donaldson, Aruna Kilaru, Timothy McDowell, Alan Windham

Abstract

A population of the rare Southern Appalachian endemic species Lilium grayi, (Gray’s lily) Roan Mountain, TN/NC was monitored for 2 years to determine the cause and impact of an early season collapse. High concentrations of the Lilium spp. host-specific fungal phytopathogen, Pseudocercosporella inconspicua (G. Winter) U. Braun were associated with 19/20 symptomatic and 0/30 asymptomatic plants. Strength of the association between pathogen and disease and the replication of disease symptoms in 4/4 healthy hosts showed that P. inconspicua was the causal agent of the disease referred to as lily leaf spot. Disease had a severe impact on the population with 59% of mature and 98% of adolescent plants undergoing early senescence. Only 32% of mature plants produced capsules and they were frequently diseased. A recurring spatiotemporal pattern typical of an infectious disease suggested that the lily leaf spot disease is capable of causing sequential annual epidemics of unknown long-term consequences to the stability of the host population.

Document Type

Thesis - Open Access

Copyright

Copyright by the authors.

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