Re-assessment of subspecific taxa in Astragalus section Anthylloidei (Fabaceae) based on molecular evidence

Document Type: Research Paper

Authors

1 Department of Plant Biology, Faculty of Biological Sciences, Tarbiat Modares University, Tehran 14155-154, Iran

2 Department of Botany, Research Institute of Forests and Rangelands, Tehran 13185-116, Iran

Abstract

The taxonomic and phylogenetic status of several taxa previously recognized as subspecies in
Astragalus sect. Anthylloidei is re-assessed based on DNA sequences and morphological
features. We focused on Astragalus ebenoides (subsp. ebenoides and subsp. naghadehensis),
Astragalus murinus (subsp. murins and subsp. bornmuelleri), Astragalus remotiflorus (subsp.
remotiflorus and subsp. melanogramma), Astragalus nigrohirsutus (=Astragalus remotiflorus
subsp. nigrohirsutus), Astragalus submitis (=Astragalus submitis subsp. submitis) and
Astragalus yushensis (=Astragalus submitis subsp. maassoumii). A total of 15 accessions
representing 14 ingroups and one outgroup were analysed for nrDNA ITS and plastid DNA,
rpl32 gene and rpl32-trnL(UAG) intergenic spacer. Phylogenetic trees were constructed using
neighbour joining, Bayesian and maximum parsimony methods. The phylogenetic analyses of
both datasets revealed that the subspecies described formerly under each of the studied species
are distinct and should be elevated to specific rank. The nucleotide sequence variations
observed among different subspecies, along with morphological characters, provided
appropriate criteria in setting the species boundaries. The new combinations and a diagnostic
key to the studied species are provided.

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