Popyploid origins in a circumplora complex in Draba (Brassicaceae) inferred from cloned nuclear DNA sequences and fingerprints

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2004 (English)In: Molecular Phylogenetics and Evolution, Vol. 32, no 3, p. 695-710Article in journal (Refereed)

Abstract [en]

Abstract Polyploid evolution has been of major importance in the arctic flora, but rarely addressed on the full circumpolar scale. Herein we study the allopolyploid Draba lactea and its close allies, which form a taxonomically intricate arctic-alpine complex including diploids, tetraploids, and hexaploids. Based on samples from the entire circumpolar area, we inferred the origins of polyploids in this complex using cloned DNA sequences from two nuclear regions (one intron from a gene encoding a second largest subunit in the RNA polymerase family, RPD2, and the ribosomal internal transcribed spacer region, ITS) and DNA fingerprints (random amplified polymorphic DNAs, RAPDs). Although D. lactea and all other polyploids examined in Draba are genetic alloploids showing fixed heterozygosity, the data obtained in the present study suggest that each of the polyploids analyzed here may have originated from a single diploid lineage: hexaploid D. lactea via tetraploid D. lactea from the D. palanderiana lineage (not from the D. fladnizensis and D. nivalis lineages as previously hypothesized), the tetraploid D. turczaninovii from the D. fladnizensis lineage, the tetraploid D. porsildii from the D. lonchocarpa lineage, and a tetraploid here named Draba spB from the D. nivalis lineage. Draba lactea has probably originated several times in the Beringian area, and it is not necessary to invoke complex origins based on a combination of different species lineages as previously suggested.

Place, publisher, year, edition, pages

2004. Vol. 32, no 3, p. 695-710

Keywords [en]

arctic plants, Draba lactea, polyploidy, SWEDARCTIC 1999, Tundra Northwest 1999, TNW 99, Arctic, North America

Identifiers

URN: urn:nbn:se:polar:diva-600OAI: oai:DiVA.org:polar-600DiVA, id: diva2:568732

Note

Source: Polardok by Swedish Polar Research Secretariat

Available from: 2012-11-15 Created: 2012-11-15 Last updated: 2012-11-15

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