Abstract

The Great Smoky Mountains National Park (GSMNP) is home to over 1,600 species of plants. Among these species is the cutleaf coneflower (Rudbeckia laciniata L. Asteraceae). The Eastern Band of Cherokee Indians (EBCI) have harvested cutleaf coneflower from the GSMNP for thousands of years. The EBCI refer to this native plant as sochan, a species which holds both nutritional and cultural significance to the EBCI and is typically harvested in spring. Throughout the almost 100-year history of the GSMNP, multiple rules and regulations pertaining to native plant collection have been administered. In 2016, a regulation was passed which allows the gathering and removal of plants or plant parts by members of Native American tribes for traditional purposes at specific locations within the park. Concerns about genetic diversity of GSMNP sochan populations have been raised, and it is not yet clear which populations and sites are best suited for harvest by the EBCI. The genetic status of these populations has yet to be characterized, and in fact, no population genetic markers have been developed for this species. The purpose of this research was to determine the best markers to use for measuring genetic diversity in R. laciniata populations and to use these markers to inform sustainable harvest practices within the GSMNP. Samples of sochan leaves were collected from sites SF, FC, and TP; within the GSMNP. Thirty leaves were taken per population and DNA was extracted from a total of 29 plants across the three populations. A total of 15 microsatellite loci were screened using polymerase chain reaction (PCR) and then gel electrophoresis. Five of these loci were used to assess the 29 samples and successfully amplified PCR products were sent for fragment analysis. Allelic diversity (A) and Lynch genetic distance was calculated, and the site with the greatest diversity was SF. The site with the least diversity based on A and Lynch genetic distance was TP. A principal component analysis comparing SF and FC showed much overlap between these two populations, indicating genetic similarity. However, the FST value between these two populations fell in the moderate genetic differentiation range. It is recommended that in order to conserve as much genetic diversity as possible, the SF population be protected from future harvests. The population at TP shows the least genetic diversity, and it is recommended to continue harvests at this site. Future research to inform sustainable harvesting of sochan can expand on this work by focusing on geospatial analysis of the data to clearly display patterns of genetic diversity within the GSMNP.

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