Analysis of population structure and assessment of clonality in Vitex rotundifolia, a non-native dune plant using AFLP markers
Plan, Albert P.
Amplified fragment length polymorphism (AFLPs) were used to investigate the population structure and to assess clonality of Vitex rotundifolia, a non-native plant introduced to the coasts of the Carolinas. Eight sites were sampled ranging from Atlantic Beach, North Carolina southward to Isle of Palms, South Carolina. Within these sites 24 ramets were sampled. Large amounts of genetic differentiation was detected among populations (T = 0.54), however none of the differentiation could be explained by geography. The program STRUCTURE clustered the eight sites into four populations that were genetically distinct. Clonality was identified as a reproductive strategy, but proportional expression varied across sites. The effect of error rate on clonality estimation was also determined. No evidence for a series of founding events was found. These results indicate that multiple independent introductions by humans were important in shaping the genetic diversity in these populations. Other species that have similar introduction histories to novel environments may also be able colonize novel habitats without significant reduction in genetic diversity.