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 the Oxytropis arctica and O. campestris species 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, including O. arctica var. 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.

Phylogenetic relationships between Oxytropis DC. and Astragalus L.species native to an Old World diversity center inferred from nuclear ribosomal ITS and plastid matK gene sequences

“…Genetic divergence was still low even after new sequences of New and Old World Oxytropis species were added to the analysis. Low genetic divergence within the genus Oxytropis was also indicated by previous studies (Wojciechowski et al, 1993;Jorgensen et al, 2003;Mikhailova et al, 2008). Archambault and Stromvik (2012) used sequence data from the ITS region to understand phylogenetic relationships in Oxytropis and also added several Astragalus species to compare the genetic diversity between them.…”

“…In the literature, there are quite a number of valuable molecular studies (e.g., Wojciechowski et al, 1993;Sanderson and Wojciechowski, 1996;Dong et al, 2003b;, 2005Wojciechowski, 2005;Scherson et al, 2008;Kazemi et al, 2009;Dizkirici et al, 2014) indicating the phylogenetic relationships among Astragalus species, while there are few studies (Jorgensen et al, 2003;Archambault and Stromvik, 2012; dealing with the molecular phylogeny of the genus Oxytropis. There is no study dealing with native Oxytropis species although Turkey is one of the diversity centers for both taxa.…”

Identification of Smallanthus sonchifolius in herbal tea mixtures by PCR and DART/TOF-MS methods

“…Internal transcribed spacers are reported in the literature as belonging among the most informative regions of variable DNA used for phylogenetic analysis to distinguish relationships within genera at the species level (Clements 2003;Jorgensen et al 2003). The nucleotide sequence of the yacon ITS that was reported previously by Žiarovská et al (2013) describes the specific nucleotides that are recognised by the DraIII restriction endonuclease.…”

Phylogenetic relationships among native Oxytropis species in Turkey using the trnL intron, trnL-F IGS, and trnV intron cpDNA regions

“…Relationships among species of the genus have been studied based on anatomical and morphological characters such as pollen morphology, seed morphology, stomata, trichome, leaf surface morphology, fruit, and flower structures by several researchers (Dickoré and Kriechbaum, 2006;Kholina and Kholin, 2008;Karaman et al, 2009;Ceter et al, 2013;Erkul et al, 2014). Even though there are numerous studies indicating morphological variations in Oxytropis species, the number of studies in the literature concentrating on phylogenetic relationships among them is limited (Jorgensen et al, 2003;Gao et al, 2009;Archambault and Stromvik, 2012;Artyukova and Kozyrenko, 2012). Furthermore, none of these studies covers all of the Turkish species.…”