Pollution and genetic structure of North American populations of the common dandelion (Taraxacum officinale).
Assessing the genetic structure of natural populations differentially impacted by anthropogenic contaminants can be a useful tool for evaluating the population genetic consequences of exposure to pollution. In this study, measures of genetic diversity at variable-number-tandem-repeat loci in six dandelion populations (3 urban and 3 rural) showed patterns that may have been influenced by exposure to environmental contaminants. Mean genetic similarity among individuals within a population was significantly and positively correlated with increasing levels of airborne particulate matter (< or = 10 microm, PM10) and soil concentrations of four metals (Cd, Fe, Ni and Pb). In addition, mean genetic similarity was always significantly higher at the urban sites compared to rural sites. There was a significant negative correlation between the number of genotypes at a site and increasing amounts of PM10, concentrations of five soil metals (Cd, Cu, Fe, Ni and Pb), leaf tissue levels of Fe and a significant positive correlation between the extent of clonality at a site and levels of PM10 and soil concentrations of five metals (Cd, Cu, Fe, Ni and Pb). Although, this study does not directly establish a causal link between the specific contaminants detected at the study sites and differences in genetic diversity, our data are consistent with the hypothesis that pollution-induced selection has contributed in some fashion to the lower genetic diversity found at the urban sites.
Keane
Brian
B
Department of Zoology, Miami University-Hamilton, Hamilton, Ohio, USA.
Collier
Matthew H
MH
Rogstad
Steven H
SH
D018744:DNA, Plant / Q000032:analysis; D004784:Environmental Monitoring; D014644:Genetic Variation; D005838:Genotype; D007087:Illinois; D007196:Indiana; D019216:Metals, Heavy / Q000032:analysis*; D018598:Minisatellite Repeats; D009820:Ohio; D010316:Particle Size; D018515:Plant Leaves / Q000737:chemistry / Q000378:metabolism; D012987:Soil / Q000032:analysis; D012989:Soil Pollutants / Q000032:analysis*; D031205:Taraxacum / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism
D018744:DNA, Plant; D019216:Metals, Heavy; D012987:Soil; D012989:Soil Pollutants