Phylogenetics of the Irano-Turanian taxa ofLimonium(Plumbaginaceae) based on ITS nrDNA sequences and leaf anatomy provides evidence for species delimitation and relationships of lineages

Abstract

In a taxonomic and molecular phylogenetic study using nuclear ribosomal internal transcribed spacer (ITS) DNA sequences and anatomical data, the taxonomic status and relationships of Irano‐Turanian Limonium spp. were investigated. The results of molecular phylogenetic analysis and anatomical synapomorphies showed that the Iranian Limonium spp. can be grouped into four major clades: (1) an unresolved clade including species of section Pteroclados as sister to all other Limonium spp.; (2) the L. axillare clade as sister to all Irano‐Turanian and Mediterranean species; (3) a poorly supported clade consisting of species of section Nephrophyllum, L. caspium, L. bellidifolium and L. iconium of section Limonium subsection Hyalolepidae and the isolated species L. sogdianum (section Siphonocalyx) and L. nudum (section Platyhymenium); and (4) a well‐supported clade including species of section Limonium subsection Limonium, part of section Sarcophyllum and L. lilacinum of section Sphaerostachys. The most diverse Mediterranean clade with many microspecies and apomictic taxa has no representatives in the Irano‐Turanian area. The ITS results agree with distribution and some morphological and anatomical characters, giving strong support for separating L. perfoliatum and L. reniforme that have been considered conspecific in all recent taxonomic treatments. An updated key to all known Iranian Limonium spp., a synopsis of all species, with distribution maps, and descriptions and illustrations of Iranian species of section Nephrophyllum are provided. © 2013 The Linnean Society of London

An expanded molecular phylogeny of Plumbaginaceae, with emphasis on Limonium (sea lavenders): Taxonomic implications and biogeographic considerations

“…Our results, although contradicting those of Lledó, Crespo, et al () by identifying two instead of three different lineages for the species of L. sect. Sarcophyllum (Figure ) , are similar to those presented by Akhani et al () and Malekmohammadi et al (). The phylogenetic placement of L. cylindrifolium as sister to L. biflorum in a clade that includes Mediterranean species (Lledó, Crespo, et al, ) is not confirmed by the current study, and instead, L. cylindrifolium is placed with other species of L. sect.…”

“…The polyphyly of L. sect. Sarcophyllum has been supported in previous phylogenetic studies (Akhani et al, ; Lledó, Crespo, et al, ; Malekmohammadi et al, ) and is confirmed here (Figure ). Lledó, Crespo, et al () recovered three different lineages for the five sampled species: L. stocksii, L. somalorum, and L. axillare were placed together, while L. cylindrifolium and L. carnosum were placed in two different clades.…”

“…Pteroclados . In addition, our results challenge the subgeneric division of Limonium proposed by Lledó, Crespo, et al () and followed by later authors (e.g., Akhani et al, ; Malekmohammadi et al, ), and postulate the extension of the limits of L. subg. Pteroclados, previously matching L. sect.…”

“…The chloroplast trnL‐F region (i.e., the trnL intron, the 3’ trnL exon, and the trnL ‐ trnF spacer), rbcL and matK genes, and the nuclear ITS region (i.e., the internal transcribed spacer 1, 5.8S rRNA gene, and the internal transcribed spacer 2) compose the genetic dataset in this study. The choice of genetic loci was informed by the availability of pre‐existing sequences for genetic markers generated in previous Plumbaginaceae and Limonium studies (e.g., Lledó et al, ; Lledó et al, ; Lledó et al, ; Lledó, Crespo, et al, ; Palacios et al, ; Ding, Zhang, Yu, Zhao, & Zhang, ; Akhani et al, ; Moharrek, Osaloo, & Assadi, ) and by a pilot study that we conducted on 12 Plumbaginaceae taxa (ten Limonium taxa: three of L. subg. Pteroclados and seven of L. subg.…”

“…Limonium from the Western Mediterranean, and concluded that this section is polyphyletic. Akhani et al () investigated relationships among Irano‐Turanian Limonium species, making taxonomic and biogeographic remarks based on both molecular and morphological data. Lledó, Crespo, et al () inferred a phylogeny with broader taxonomic sampling of Limonium , including 46 species representing all sections defined by Boissier ( ; at least one species per section), plus 24 species from 16 other Plumbaginaceae genera; all species were represented by one sample.…”