Poster

         Population Genetics/Genomics

Triploids, Tetraploids, and Hexaploids, Oh My! Cogongrass Ploidy Distribution Throughout the Invaded Range

Presenting Author
Elizabeth Esser
Description
Cogongrass (Imperata cylindrica) is one of the worst invasive plants impacting the southeastern United States, where it threatens native biodiversity and economic productivity by forming dense monocultures, altering fire behavior and regimes, and is a major obstacle to restoration and afforestation efforts. Unlike many invasive plants that only have one ploidy level in the invaded range, cogongrass has been shown to have high levels of genetic diversity and has been found to be variable in ploidy, including diploid, triploid, tetraploid, or hexaploid in the invaded range of the southeastern United States. The effectiveness of cogongrass management could be variable due to cogongrass ploidy level; however, only preliminary research has been conducted to assess ploidy levels. The potential impact regarding the spatial distribution or ecological implications of variable ploidy on its spread and management has yet to be studied. Microsatellites have been successfully used to identify ploidy in other plants, but microsatellites have not yet been tested for ploidy identification in cogongrass. This study investigates potential use of microsatellite markers to map the spatial distribution of cogongrass’s variable ploidy in the invaded ranges. Preliminary results from this study will be presented and discussed. We predict that microsatellite markers will be capable of detecting ploidy in cogongrass, and we will use accessions with known ploidy levels previously determined by flow cytometry and squashes of meristematic tissues to test accuracy of these microsatellite markers. Understanding ploidy distribution may help target and refine control efforts by identifying populations that have higher or a diversity of ploidy levels and thus may possess higher genetic diversity, and therefore, adaptive capacity, which could increase the likelihood of invasion success or resistance to management.