Defense Date

2019

Document Type

Thesis

Degree Name

Master of Science

Department

Biology

First Advisor

Andrew J Eckert

Second Advisor

Rodney Dyer

Third Advisor

Christopher Gough

Fourth Advisor

Catherine Hulshof

Abstract

Foxtail pine (Pinus balfouriana) is a subalpine conifer endemic to California, notably separated into two disjunct subspecies. Previous studies have described the northern subspecies,Pinus balfouriana subsp. balfouriana,as having an uncommonly high level of genetic differentiation and no discernible spatial patterns in phenotypic variation. This study seeks to characterize the spatial genetic structure and patterns of selection of the northern subspecies (Pinus balfouriana subsp. balfouriana) using genome-wide data and to identify the influence of ecology and environment on the unique genetic patterns. I show that genetic differentiation among populations is much less than previously estimated (FST= 0.000644) and there is weak isolation-by-distance structure, but ongoing gene flow is unlikely. Within populations, stand density and competitor effects contribute to inbreeding. I also show that previously measured traits are predominantly determined by genetics. Analyzing by sliding window in the genome, I show that connectivity patterns vary widely throughout the genome and identify several areas that are important to the genetic architecture of the phenotypic traits and plasticity (GxE). Overall, there is high connectivity, genetic similarity, and genetically based trait variation among and within populations of the northern subspecies of foxtail pine due to historical processes, despite biotic interactions driving inbreeding. Persistent genetic isolation, however, may make adaptation to future climate a challenge for the subspecies.

Rights

© The Author

Is Part Of

VCU University Archives

Is Part Of

VCU Theses and Dissertations

Date of Submission

8-9-2019

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