Relationships Between Genetic and Ecological Variables in Nine Populations of Phlox Drummondii Hook (Niche, Allozymes, Genetic Differentiation)

The niche-variation hypothesis, which predicts a correlation between niche breadth and level of genetic variation, was tested using nine populations of the annual plant, Phlox drummondii, from south central Texas. Niche breadth was measured as population response along controlled environmental gradients. Statistically significant differences among populations in survival, vegetative growth, and flowering were observed in response to different levels of moisture, light, nutrients, and competition. Differences in germination were observed in response to temperature and nutrient levels. Genetic variation was quantified by examining allozyme variability at five polymorphic loci and by analysis of morphological variation among families of full and half sibs. Statistically significant heritabilities were found for 16 morphological and life history characters, as well as significant differences among populations in levels of additive genetic variance. Despite widespread differentiation among these populations for both genetic and ecological variables, no relation emerged between niche breadth and genetic variation.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Plant Biology

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2014

Author dc:creator

• Schwaegerle, Kent Edward

• Biology, Botany

Identifier

(UMI)AAI8502294

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/71278