Abstract Detail

Ecology

Miller , John (Tony) [1].

Modeling Sex Ratio Variation in Lobelia siphilitica L. (Campanulaceae).

In cytonuclear gynodioecious plants, population sex ratios vary substantially among populations, providing an opportunity to study the maintenance of polymorphism (in this case, maintenance of females and hermaphrodites in a population). Populations of one gynodioecious species, Lobelia siphilitica L., span from 0% to near 100% females. Furthermore, the populations with higher percentages of females are geographically structured toward the south-central part of the species range. One potential mechanism explaining this geographical structuring of sex ratio variation is the variability of abiotic factors across the species range. In this study, we constructed environmental models to explain the variation of sex ratios across the species range of L. siphilitica. We used a dataset of sex ratios, climatic variables (from WorldClim), and soil variables (from US Geological Survey) for 166 populations spanning the Midwest to the northeastern United States and Ontario, Canada. We used a forward selecting redundancy analysis to determine which variables would be used for model construction. Of the 19 climate variables and 12 soil variables, 10 variables were selected for model construction. Among the 10 variables were mean annual temperature (populations in warmer areas tend to have more females), annual precipitation (populations in areas with more precipitation tend to have more females), and clay content (populations in areas with more clay tend to have more females). We used the 10 variables to develop a model based on the abiotic factors, termed BioClim model. Additionally, we developed 3 additional models: Maximum Entropy model (MaxEnt), Generalized Linear Model (GLM), and a Geospatial model. Here, we present the evaluation of these constructed models. The BioClim model performed best when evaluating goodness of fit. We will be using the results of these models to investigate potential abiotic factors and how they affect relative fitness of females and hermaphrodites.

1 - Kent State University, Department of Biological Sciences, 256 Cunningham Hall, Kent, OH, 44242, USA

Keywords:
gynodioecy
Lobelia siphilitica
ecological niche model.

Presentation Type: Poster
Session: P, Ecology
Location: Grand Ballroom - Exhibit Hall/Mayo Civic Center
Date: Monday, July 23rd, 2018
Time: 5:30 PM This poster will be presented at 5:30 pm. The Poster Session runs from 5:30 pm to 7:00 pm. Posters with odd poster numbers are presented at 5:30 pm, and posters with even poster numbers are presented at 6:15 pm.
Number: PEC027
Abstract ID:914
Candidate for Awards:None