Structure of allozyme variation in Nordic Silene nutans (Caryophyllaceae): population size, geographical position and immigration history

• Published in: Biological journal of the Linnean Society Vol. 81; no. 3; pp. 357 - 371
• Main Authors: Rossum, F. van, Prentice, H.C
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Ltd 01-03-2004; Blackwell
• Subjects: Biologi; Biological and medical sciences; Biological evolution; Biological Sciences; bottlenecks; contact zone; Ecology; Ekologi; Fundamental and applied biological sciences. Psychology; Genetics of eukaryotes. Biological and molecular evolution; habitat fragmentation; Natural Sciences; Naturvetenskap; postglacial immigration; range periphery; Silene nutans; soil pH; Sweden; Finland; Population number; Immigration; Allozyme; Position; Biological evolution
• ISSN: 0024-4066; 1095-8312
• DOI: 10.1111/j.1095-8312.2003.00301.x

We investigated allozyme variation in 34 populations of the perennial herb Silene nutans from Sweden and northern Finland, areas that were ice‐covered during the last (Weichselian) glaciation. The present geographical structure of genetic variation in S. nutans in Sweden and northern Finland appears to have been mainly shaped by ancient historical processes. Patterns of variation in allele frequencies suggest two major postglacial immigration routes into Sweden, with populations entering the area from both the south and the east and forming a contact zone with admixed populations in central Sweden. While estimates of within‐population genetic diversity and allelic richness are significantly correlated with present population size and geographical position (latitude), population size is not correlated with latitude. Low genetic diversity in the northern populations is more likely to have resulted from ancient stochastic events during the process of immigration than from recent population fragmentation. FIS values are high and increase with latitude. Evidence of recent bottlenecks was detected in several southern Swedish populations: these can be interpreted in terms of population fragmentation as a result of anthropogenic disturbance. Soil pH is uncorrelated with population size and position. © 2004 The Linnean Society of London, Biological Journal of the Linnean Society, 2004, 81, 357–371.