Clarification of the Position of Linum stelleroides Planch. within the Phylogeny of the Genus Linum L.

Nadezhda L Bolsheva,Olga Y Yurkevich,George S Krasnov,Ekaterina M Dvorianinova,Alexey A Dmitriev,Olga V Muravenko,Alexandra V Amosova,Liudmila N Mironova,Nataliya V Melnikova

doi:10.3390/plants11050652

Abstract

The phylogeny of members of the family Linaceae DC. ex Perleb has not been adequately studied. In particular, data on the phylogenetic relationship between Linum stelleroides Planch. and other representatives of the blue-flowered flax are very controversial. In the present work, to clarify this issue, we obtained DNA sequences of three nuclear loci (IGS and ITS1 + 5.8S rDNA + ITS2 of the 35S rRNA gene and the 5S rRNA gene) and eight chloroplast loci (rbcL, the trnL–trnF intergenic spacer, matK, the 3′ trnK intron, ndhF, trnG, the psbA–trnH intergenic spacer, and rpl16) of 10 Linum L. species (L. stelleroides, L. hirsutum, L. perenne, L. leonii, L. lewisii, L. narbonense, L. decumbens, L. grandiflorum, L. bienne (syn. L. angustifolium), and L. usitatissimum) using high-throughput sequencing data. The phylogenetic analysis showed that L. stelleroides forms a basal branch in the blue-flowered flax clade. Previously found inconsistencies in the position of L. stelleroides and some other species in the Linaceae phylogenetic tree resulted from the erroneous species identification of some of the studied plant samples.

Highlights

Linum stelleroides Planch., an annual, wild-growing species, was named after German naturalist Georg Steller, who explored the nature of Siberia, the Far East, and Alaska
According to botanical descriptions [3,4], L. stelleroides is an annual; its flowers are ~1 cm in diameter; its petals are pink-violet, sometimes blue-violet, and rarely white; the sepals are 3–5 mm long and rounded ovate with a sharp apex; the sepal margins are narrowly bordered with characteristic sessile rounded black glands of a rather large size; capsules are acuminate, subglobose, 4–5 mm long and 4–5 mm wide; and the seeds are rather small, i.e., ~2 mm in length and brown colored
The morphological features of the L. stelleroides specimen collected in the Far East of Russia correspond completely to those described at the end of the previous paragraph (Figure 1e–h)

Summary

Introduction

Linum stelleroides Planch., an annual, wild-growing species, was named after German naturalist Georg Steller, who explored the nature of Siberia, the Far East, and Alaska. The species is distributed across the southern Far East and Eastern Siberia in Russia, China, Japan, Korea, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan. Based on several morphological characteristics, L. stelleroides differs significantly from other members of the genus Linum. L. stelleroides has pantoporate pollen grains with 12 pores, whereas the members of the other three sections have tricolpate pollen, except for a few polyploid species which have polycolpate pollen [1,2]. These differences provided the basis for categorizing L. stelleroides within a separate monotypic section of Stellerolinum Juz. These differences provided the basis for categorizing L. stelleroides within a separate monotypic section of Stellerolinum Juz. [1–4]

Methods

Results

Conclusion