Preliminary Genetic Evidence of Hybridization in a Sympatric Population of Southern and Northern Cricket Frogs
Amphibian declines are well documented and are often associated with multiple anthropogenic as well as natural factors. One consequence of alterations in species’ habitat may be the increased probability of hybridization. Although pre-reproductive barriers in Anurans are well-documented, studies suggest declines in several species of Cricket Frog yet few examine possible hybridization in areas of sympatry. In spring of 2012, we began examining a sympatric population of Northern (Acris crepitans) and Southern cricket frogs (A. gryllus) from northern Mississippi. Identification using morphological features presented in previous works suggests a large presence of hybrids, with very few individuals exhibiting character sets indicative of a single species, particularly of the northern variety. However, identification of these species by morphology may not be diagnostic causing character scores to become problematic. Using 4 established nuclear markers, we assigned animals to one of three categories: northern, southern, or hybrid. We present data and preliminary analysis from cricket frogs collected from the same location during the spring of 2012 and summer of 2013. Based upon morphological data, proximity of habitation, and the influence of environmental factors, we predict high numbers of hybrids and few pure individuals of either species.
Wittenberg University
P75 • Kristen Oliver1, Jennifer S. Borgo1, Rebecca Heiss2
Bacterial Growth Inhibition of the Uropygial Glands Secretions of Passerines in South Carolina
We examined whether secretions of the uropygial gland inhibit growth of the feather degrading bacterium Bacillus licheniformis or E.coli differently depending on environment. Birds were mistnetted monthly at three trapping sites located near Hartsville (inland), Georgetown (coastal), and Awendaw (coastal), SC from May to August, 2013. Captured birds were identified to species, and uropygial samples were collected and placed in solutions of PBS. Bacterial assays were conducted using techniques modified from French and Neuman-Lee (2012). Using a 96-well plate, each sample was distributed into 4 wells. B. licheniformis was added to two of those wells. E.coli was added to the other two. After incubation, dilution series were prepared for each well, and samples were plated onto TSA. The plates were incubated overnight and counted. The average growth inhibition of B.licheniformis for all samples was -6902% indicating an increase in reproducing colonies. However, values ranged from -219344% to >99%. No significant differences were found in the ability of gland secretions to inhibit growth of either bacterium when comparing between coastal and inland birds or between the sexes. Finally, no correlation was found in the ability of uropygial secretions to inhibit growth of B. licheniformis and E.coli (r=-0.27, P=0.15). Individuals within a species differed appreciably in their abilities to inhibit the growth of B. licheniformis and further investigation is necessary to determine the reason for this variabilty.
1Coker College, Hartsville, SC; 2 South Carolina Governor’s School for Science and Mathematics, Hartsville, SC
P76 • John F. Darling, Alanna M. Wentworth, Lauren A. Ballou, Sophia Almammary, Christopher A. Adams
A Study on the Seed Germination Ecology and Seedling Survivorship of the Endangered Cream Gentian Gentiana flavida
Gentiana flavida is an endangered species in Kentucky, with populations known from only five counties. Little is known about the life history of this species. The purpose of this project was to examine the initial stages of the species’ life history: seed germination and seedling survivorship. Initial tests determined that the seeds are dormant at maturity. This study attempted to discover the proper dormancy-breaking conditions for maximum seed germination and to determine the necessary growth medium for maximum seedling establishment. Mature seeds were placed in a 5° C incubator for varying time periods (0-12 weeks), simulating the cold stratification that seeds would receive in the field during winter. Next, each group of seeds was moved to a 25° C incubator and germination was monitored. To determine ideal growth medium conditions, G. flavida seedlings were placed in three different soil treatments (mychorrizal inoculated, non-mychorrizal, and soil from the field site) and then monitored over time for survivorship. Results indicated that the 12 week cold stratification treatment produced a significantly higher percent germination (73%) than stratification at 8 (61%), 4 (8%), or 0 (0%) weeks. Among the growth medium treatments, soil collected from the field site contained seedlings with the highest seedling survivorship (67%), significantly higher than the other two treatments. Potting media that contained mychorrhizal inoculants showed higher survivorship (38%) than media that was not inoculated (2%). In conclusion, for maximum germination and juvenile survivorship, seeds should receive 12 weeks of cold stratification and have exposure to mychorrizal soil microbes.
