Microsatellite evidence of facultative outcrossing in cheatgrass (Bromus tectorum): Implications for the evolution of invasiveness
Citation
William S Longland, and Michael C Ashley, Microsatellite evidence of facultative outcrossing in cheatgrass (Bromus tectorum): Implications for the evolution of invasiveness: .
Summary
The presence or absence of heterozygous individuals and overall genetic variation were determined for the invasive exotic annual grass Bromus tectorum from four populations in northern Nevada using seven species-specific polymorphic di-nucleotide microsatellite markers. Allelic polymorphisms were found in all populations, but not at all loci within each population. Mean genetic diversity across loci within populations ranged from 0.009 ± 0.006 to 0.551 ± 0.073, across populations x̄ = 0.234 ± 0.043. Fifteen individuals from the total sample (8.24%) were heterozygous at 1–4 loci. Two populations exhibited no heterozygosity and the remaining two populations had relative heterozygote proportions of 22.5% and 12.1%. Facultative outcrossing [...]
Summary
The presence or absence of heterozygous individuals and overall genetic variation were determined for the invasive exotic annual grass Bromus tectorum from four populations in northern Nevada using seven species-specific polymorphic di-nucleotide microsatellite markers. Allelic polymorphisms were found in all populations, but not at all loci within each population. Mean genetic diversity across loci within populations ranged from 0.009 ± 0.006 to 0.551 ± 0.073, across populations x̄ = 0.234 ± 0.043. Fifteen individuals from the total sample (8.24%) were heterozygous at 1–4 loci. Two populations exhibited no heterozygosity and the remaining two populations had relative heterozygote proportions of 22.5% and 12.1%. Facultative outcrossing is discussed as an aspect of reproductive plasticity in cheatgrass and as a mechanism promoting the evolution of invasive genotypes.
Published in Plant Species Biology, volume 22, issue 3, on pages 197 - 204, in 2007.
