Date of Graduation

Spring 2024

Degree

Master of Science in Biology

Department

Biology

Committee Chair

Avery Russell

Abstract

Flowers host diverse communities of epiphytic bacteria, which can impact floral functions, pollinator interactions, and overall plant fitness. However, little is known about how the abundance of these bacteria change as flowers age, and how these shifts may correlate with floral longevity. In this study I investigate the change in bacterial abundance across the lifespan of a flower from anthesis (opening of bud to flower) to senescence (wilting of flower) and to explore the potential implications for floral longevity. We tracked the age of the flowers by determining the average age to senescence in flowers of 8 plant species over two field seasons. Flower buds were tagged prior to anthesis, allowing us to track flower lifespan from the moment of bud opening, which marked the start of their anthesis, to the onset of visible wilting, indicating the initiation of senescence, we determined the abundance of culturable bacteria on flower surfaces through plate counting and measured how environmental temperature, humidity, and precipitation influenced these patterns. Our results showed that flowers accumulate bacteria as they age, with shorter-lived flowers generally amassing bacteria more rapidly than longer-lived ones. However, contrary to expectations, epiphytic bacterial abundance did not correlate with flower longevity, suggesting that epiphytic bacteria may not directly influence floral longevity. Instead, environmental conditions played a prominent role; higher temperatures were associated with reduced bacterial abundance, while increased humidity supported both greater bacterial abundance and extended floral lifespan. These findings indicate that bacterial abundance on flowers may be shaped by external factors with no direct impact on flower longevity, highlighting the complex interplay between floral aging, and environmental conditions.

Keywords

Culturable bacteria, epiphytic bacteria, flower longevity, bacterial abundance, interactions, flower senescence, temperature, precipitation

Subject Categories

Ecology and Evolutionary Biology | Environmental Microbiology and Microbial Ecology

Copyright

© Rita Nkem Afagwu

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