Microsatellite polymorphism and genetic differentiation in three Norwegian populations of Elymus alaskanus (Poaceae) |
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Authors: | G-L Sun B Salomon R von Bothmer |
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Institution: | (1) Biology Department, Saint Mary's University, Halifax, Nova Scotia, Canada, CA;(2) Department of Crop Science, The Swedish University of Agricultural Sciences, Alnarp, Sweden, SE |
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Abstract: | Variation at seven microsatellite loci was investigated in three local E. alaskanus populations from Norway and microsatellite variation was compared with allozyme variation. The percentage of polymorphic
loci was 81%, the mean number of alleles per polymorphic locus was 5.7 and expected heterozygosity was 0.37. An F-statistic
analysis revealed an overall 48% deficit of heterozygotes over Hardy-Weinberg expectations. Gene diversity is mainly explained
by the within population component. The averaged between population differentiation coefficient, F
st
, over 7 loci is only 0.13, which accounts for only 13% of the whole diversity and was contrary to allozyme analysis. The
mean genetic distance between populations was 0.12. However, a χ2 -test showed that allele frequencies were different (p < 0.05) among the populations at 5 of the 7 loci. In comparison with
the genetic variation detected by allozymes, microsatellite loci showed higher levels of genetic variation. Microsatellite
analysis revealed that population H10576 possesses the lowest genetic variation among the tested three populations, which
concur with allozyme analysis. The dendrogram generated by microsatellites agreed very well with allozymic data. Our results
suggest that natural selection may be an important factor in shaping the genetic diversity in these three local E. alaskanus populations. Possible explanations for deficit heterozygosity and incongruence between microsatellites and allozymes are discussed.
Received November 6, 2001; accepted April 24, 2002 Published online: November 14, 2002
Addresses of the authors: Genlou Sun (e-mail: Genlou.sun@STMARYS.CA), Biology Department, Saint Mary's University, Halifax.
Nova Scotia, B3H 3C3, Canada. B. Salomon, R. von Bothmer, Department of Crop Science, The Swedish University of Agricultural
Sciences, P.O. Box 44, SE-230 53, Alnarp, Sweden. |
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Keywords: | : Elymus alaskanus microsatellites genetic diversity heterozygote deficit population structure genetic differentiation |
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