Date Awarded

2024

Document Type

Thesis

Degree Name

Master of Science (M.Sc.)

Department

Biology

Advisor

Joshua Puzey

Committee Member

Harmony Dalgleish

Committee Member

Ron Smith

Committee Member

Michael D. Lamar

Abstract

This study examines the influence of plant hybridization, environmental factors, and long-term neighborhood effects on A. exaltata and A. syriaca soil and phyllosphere microbiomes. Our approach is an in situ study of milkweed plants in natural hybrid zones and their associated microbiomes. Our approach captured variation in genotype, leaf and soil nutrients, and geographic location to distinguish the varying influences on plant-associated microbiomes. Our analyses demonstrated that inter-species hybridization influences the number of taxa in phyllosphere microbiomes while having a limited influence on the composition of soil and phyllosphere microbiomes. Instead of genotype explaining variation in microbiome composition we found that environmental factors and geographic distance, as a proxy for long-term neighborhood effects, strongly influenced the composition of plant-associated microbiomes. Specifically, soil organic matter, cation exchange capacity, and soil pH were important factors influencing plant-associated microbiomes in milkweed. Overall, we found that plant-associated microbiomes of milkweed plants A. syriaca and A. exaltata are dominated by environmental factors and neighborhood effects, while plant host species and hybridization appears to influence the prevalence of rare or specialized microbes. Future research is needed to understand the specific mechanisms influencing rare microbial taxa in plant-associated microbiomes, as well as the mechanisms of environment factors influencing plant-associated microbiome composition.

DOI

https://dx.doi.org/10.21220/s2-t8pd-9y81

Rights

© The Author

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