Implications of ITS sequences and RAPD markers for the taxonomy and biogeography of theOxytropis campestrisandO. arctica(Fabaceae) complexes in Alaska
Abstract
Taxonomic consensus is lacking on theOxytropis arcticaandO. campestrisspecies complexes, two polyploid complexes found in the interior and arctic areas of Alaska. One classification has emphasized flower size, whereas flower color is considered a key diagnostic character in another classification. Our analyses of internal transcribed spacer (ITS) sequences and random amplified polymorphic DNA (RAPD) markers provided no support for either classification system. The trees generated from ITS sequences and the phenogram derived from RAPD markers suggest that most recognized taxa in the two complexes are probably polyphyletic, includingO. arcticavar.barnebyana, which is listed as threatened in Alaska. The only consistent pattern detected by both types of molecular markers was a geographic split dividing the northeastern arctic populations from most other populations (48.60–55.03% in AMOVA analyses). This genetic subdivision probably reflects a Pleistocene barrier formed by the northern coastal ice shield. Our molecular data, in conjunction with the previously reported variation of ploidy levels in these groups, suggest a scenario of recent and multiple origins of polyploidy. It is possible that most Alaskan populations of these two complexes are best referred to as a single taxonomic species despite morphological differentiation within the complexes.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Oct 01, 2003
- Source ID
- 10.3732/ajb.90.10.1470
Entities
People
- Christian Brochmann
- Elena Conti
- Ivana Stehlik
- Janet L. Jorgensen
Organizations
- United States Air Force