GRADUAL LOSS OF GENETIC DIVERSITY OF Ambrosia artemisiifolia L. POPULATIONS IN THE INVADED RANGE OF CENTRAL SERBIA

As an invasive allergenic weed, Ambrosia artemisiifolia L. causes serious public health and economic problems in invaded ranges of Europe. Over the last two decades, while expanding toward southern parts of Serbia, this common ragweed has become a very troublesome plant species in the whole country. Considering the importance of genetic studies in understanding of invasive species, our main objectives in this study were to analyze the genetic diversity and genetic structure of Ambrosia artemisiifolia populations from Central Serbia, a relatively recently invaded region. Comparing values of genetic measures obtained by microsatellite analyses, a number of differences were detected in genetic diversity between sampled populations. Allelic richness-r (ranged from 5.42 to 7.80), the mean number of alleles per locus-N-A (5.8-8.4) and the mean number of rare alleles per locus-N-R (2.8-5.8) have quite similar ranges across populations. We observed greater genetic variability in populations from the northern part of investigated area than in southern populations. Based on pairwise Fst values, AMOVA results and PCo Analysis, moderate differentiation among population was detected, while the STRUCTURE analysis clearly separated SR-Kru and SR-Les. Data obtained for analyses of differentiation and gradual losses of genetic diversity of sampled populations provides useful information about invasion dynamics of common ragweed in recently invaded region.