Molecular analysis of genetic diversity in Florida sea-oats (Uniola paniculata) populations: New approaches to generate and analyze molecular data

Sea-oats (Uniola paniculata L.) is a pioneer coastal grass used for dune restoration projects. Concerns about altering the genetic constitution and population dynamics of sea-oats in restoration projects has generated a need to understand its inherent genetic variation and how that information might affect the successful development of restored dunes relative to their ecology and protection of coastal structures. To determine the genetic variation, sea-oats population studies were conducted using adult plants and seedlings from four Florida populations on the Atlantic and Gulf coasts. From each population, 23 adult plants and 18 seedlings were sampled. Random amplified polymorphic DNA (RAPD) generated data using 10 random primers were subjected to statistical analyses. Genetic analyses revealed that both adult and seedling plants displayed high within- and between-population genetic variation, and extensive genetic differentiation between the coasts. Highest within-population variation was observed on the Gulf coast with St. George Island producing the highest variation, followed by Egmont Key. In contrast, the Atlantic populations showed the least within- and between-population differentiation. These population and coastal differences were attributed to: (1) frequent storm disruptions on the Gulf coast causing high genetic variation associated with population disturbances; (2) higher levels of gene flow between populations on the same coast favoring homogenization; and (3) restricted levels of gene flow between populations on the two coasts. Coastal genetic differences suggested possible ecotypic differences; however, common-garden and reciprocal transplant studies are required to assess actual adaptability.; New procedures to generate and analyze molecular data were developed. Genetic recombination, as revealed by molecular markers, was explored to obtain information on reproduction modes using adult sea-oats population genetic data. Based on this study, relative levels of genetic diversity, occurrence of clone-mates in populations, and spatial distribution and genetic relationships between clone-mates were found. A standard amplified fragment length polymorphism (AFLP) technique was modified to generate markers with high reproducibility and specificity, with the same convenience of RAPD. A comparison between modified AFLP technique and RAPD using a number of plant species showed that individuals, cultivars, and ecotypes can be efficiently and reliably differentiated using this modified AFLP technique.