Genetic analysis of invasive plant populations at different spatial scales

invasive plants, molecular markers, selection, spatial scale Measuring genetic diversity requires selection of a spatial scale of analysis. Different levels of genetic structuring are revealed at different spatial scales, however, and the relative importance of factors driving genetic structuring varies along the spatial scale continuum. Unequal gene flow is a major factor deter-mining genetic structure in plant populations at the local level, while the effect of selection imposed by environmental heterogeneity increases with the spatial scale of analysis. At a continental and global scale genetic structure of invasive plant populations is significantly affected by founder effect and propagule transport via human vectors. Although genetic analysis at one spatial scale provides only partial infor-mation about the invasion process, little published research reports such data for the same species at multiple scales. A multi-faceted approach to investigating the genetic structure of invasive plant species that incorporates sampling at different spatial and temporal scales would provide a more complete picture of the role of genetic forces in invasion. Abbreviations: AFLP – amplified fragment length polymorphism; cpDNA – chloroplast DNA; EST – expressed sequence tag; ISSR – inter-simple sequence repeat; mtDNA – mitochondrial DNA; ncDNA