Date of Award
Master of Science in Integrative Biology (MSIB)
Joel R. McNeal
First Committee Member
Thomas C. McElroy
Second Committee Member
Paula C. Jackson
Cuscuta harperi is a rare parasitic plant endemic to a small number of widely disjunct populations in Georgia and Alabama. It is a habitat-specialist, occurring on sandstone and granite outcrops within its limited range; it is also exhibits a high level of host specificity, parasitizing only a few select species. C. harperi is of conservation concern due to small population sizes and threats from habitat degradation.
Here we develop genetic markers to address questions regarding population genetics of the species. We discuss the utility of microsatellites and single nucleotide polymorphisms as molecular markers to evaluate genetic variability between individuals and across populations. We also investigate patterns of host selection in populations of C. harperi using greenhouse and field-based experiments.
We failed to find variation in putative microsatellite markers and conclude that methods of SNP detection, such as targeted sequence capture, are likely to be superior for identification of polymorphisms in the genome of C. harperi. We also show that host selection by C. harperi is a result of active choice by seedlings and that there are additional environmental factors contributing to patterns of host use observed in natural populations. Finally, we discuss the design and implementation of a project that combines in situ and ex situ strategies for the conservation of the species.