Date of Completion

2021

Document Type

Honors College Thesis

Department

Biology

Thesis Type

Honors College

First Advisor

Alison K. Brody

Keywords

mycorrhizae, floral rewards, nectar

Abstract

Most plants associate with mycorrhizal fungi in a relationship known as ‘mycorrhizae,’ where fungi colonize plant roots and exchange nutrients and water for photosynthetic sugars from their host plant. In addition to fungi, most flowering plants associate with animal pollinators to reproduce. Mycorrhizal fungi can influence plant-pollinator interactions by affecting plant floral traits important to pollinator attraction, yet the mechanisms of this relationship are not understood. We hypothesized an indirect pathway linking mycorrhizae to host plant reproductive fitness through changes to floral rewards important to pollinators, and we further predicted mycorrhizal effects to depend on the host-plant genotype. To study this, we examined floral reward and berry production over five cultivars of highbush blueberry (Vaccinium corymbosum; Ericaceae) plants treated with a commercial fungal inoculum. We measured variables of 1) nectar and pollen quantity, 2) nectar sugar and caloric content, 3) berry quantity, 4) berry sugar content, 5) seed set, and 6) the proportion of root cells colonized by mycorrhizal fungi. We found mycorrhizal treatment to increase nectar production for one cultivar and alter berry production in cultivar-dependent ways. We conclude that nectar production may be a direct link by which mycorrhizal partners may indirectly alter pollinator behavior, and that response to inoculation is genotype-dependent.

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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