Taxonomic Composition of Iris Subser. Chrysographes (Iridaceae) Inferred from Chloroplast DNA and Morphological Analyses.

Eugeny V Boltenkov,Elena V Artyukova,Anna Trias-Blasi

doi:10.3390/plants10112232

Abstract

The species of Iris subser. Chrysographes are herbaceous perennials found mainly in southwestern and central China and also in the Eastern Himalayas. To date, six species have been recognized in this group. In the framework of its taxonomic revision, we have carried out molecular and morphological studies. For this, we have sequenced four chloroplast DNA regions (trnS–trnG, trnL–trnF, rps4–trnSGGA, and psbA–trnH) for 25 samples across the major distribution ranges of the six species. Our phylogenetic analyses evidence that I. subser. Chrysographes is indeed a monophyletic group, which is sister to I. subser. Sibiricae. Within I. subser. Chrysographes, we have recovered four divergent lineages further supported by diagnosable morphological traits and geographical distributions. In this context, our data confirm the recognition of I. clarkei, I. delavayi, and I. wilsonii in their traditional concepts. Furthermore, both molecular and morphological data support the close affinities and similar distribution ranges of I. bulleyana, I. chrysographes, and I. forrestii, which suggests including I. chrysographes and I. forrestii as color forms in I. bulleyana. A revised taxonomic treatment for the group, including the notes on the species distributions and habitats, and also an identification key to the species are provided.

Highlights

While revising the series Sibiricae (Diels) G.H.M.Lawr. of the section Limniris Tausch of the genus Iris L., we found that the taxonomy of this group remains unclear [1]
Sibiricae are connected into a single network without loops and derived from the same extinct ancestral haplotype related through many mutational steps with the haplotype of I. pseudacorus
Haplotypes of this group are found in samples of I. bulleyana (C1, C5, and C6), as well as in samples of I. chrysographes (C2) and I. forrestii (C3 and C4)

Summary

Introduction

While revising the series Sibiricae (Diels) G.H.M.Lawr. of the section Limniris Tausch of the genus Iris L., we found that the taxonomy of this group remains unclear [1]. While revising the series Sibiricae (Diels) G.H.M.Lawr. Of the section Limniris Tausch of the genus Iris L., we found that the taxonomy of this group remains unclear [1]. Sibiricae includes rhizomatous herbaceous perennials morphologically distinguished mainly by their hollow flowering stems (except for I. clarkei Baker ex Hook.f.). The infrageneric taxon Sibiricae was proposed by Diels [2] as a subsection including eight species. Simonet [3] subdivided this subsection into two groups on the basis of their chromosome numbers. The distinctness of the two subseries, recognized on morphological ground and from their distributions [4,5], gained support from molecular studies [6,7]

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