Genetic Diversity in Adults and Seedlings of Celastrus orbiculatus Thunb. (Asian Bittersweet) Near a Site of Initial Introduction in Asheville, North Carolina

Gradise Nishimwe

Biology

Jennifer Rhode Ward

Asian Bittersweet (Celastrus orbiculatus) is a woody non-native species introduced to the United States in the 1860s as an ornamental. C. orbiculatus threatens the environment and other plants, especially its native congener, American Bittersweet (Celastrus scandens). The two lianas hybridize easily on the landscape, and C. orbiculatus can outcompete the native plant to cause local extinctions. The objectives of this study were to test the efficacy of new microsatellite markers, then use those markers to determine the genetic diversity of seedlings and adults of C. orbiculatus from western North Carolina, near one site of C. orbiculatus’ introduction, to gain insight into this non-native species' evolutionary forces and genetic pattern. DNA was extracted from the leaves of both adults and seedlings, and extracts were PCR amplified at seven variable microsatellite loci. All the loci tested were good enough to provide information about Asian Bittersweet. 4 or 5 of the microsatellite markers were sufficient to analyze the genetic diversity of Asian Bittersweet. Results showed that broad genetic similarities between adults and seedlings across all sites, and although allelic diversity was higher in adults, the difference was not statistically significant. This could indicate that natural selection, nonrandom mating, and/or genetic drift reduce the next generation’s diversity. This study is one of the first to compare diversity across generations of a non-native species, and results could have implications for other systems.

Jan-9-2024