Date of Completion

2021

Document Type

Honors College Thesis

Department

Biology

Thesis Type

College of Arts and Science Honors, Honors College

First Advisor

Alison Brody

Abstract

Plant-fungal partnerships can affect a variety of plant reproductive traits, and some of these traits may affect pollinator behavior. Mycorrhizal fungi reside in plant roots and provide nutrients in exchange for photosynthetic carbon. In some cases, plants with greater fungal colonization have enhanced reproductive traits such as floral displays and floral rewards, which may influence pollinator behavior. The purpose of this study was to evaluate whether colonization with mycorrhizal fungi affects pollinator visitation to highbush blueberry plants. To investigate this relationship, we observed pollinator visitation to highbush blueberry plants that either had or had not been inoculated at planting several years earlier. Observations were conducted at two locations in Vermont during summer 2020: the George D. Aiken Forestry Sciences Laboratory in Burlington, Vermont and Waterman Orchards in Johnson, Vermont. Inoculated plants received more total visits than control plants at both sites (146:86 visits at Aiken Labs; 414:387 visits at Waterman Orchards). However, large bumblebees spent on average 22% longer per flower on flowers of control plants than inoculated plants at Aiken Labs (F1,22=4.614; p=0.043), and, at Waterman Orchards, smaller bodied, orange bumblebees visited on average 74% more flowers on inoculated plants than control plants (F1,8=6.658; p=0.0326). Large-bodied bumblebees spent longer per plant on plants with higher fungal colonization at Waterman Orchards, but they spent longer per plant on plants with lower fungal colonization at Aiken Labs. Our results provide evidence that fungal communities may influence plant investment in flowers and floral rewards in ways that matter for pollinator decision making, which could have important implications for plant fitness.

Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.

Available for download on Wednesday, May 18, 2022

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