The Scandinavian Syntrichia ruralis complex (Musci, Pottiaceae): a chaos of diversification

Jochen Heinrichs,Lars Hedenäs,María Teresa Gallego

doi:10.1007/s00606-019-01596-0

Abstract

This study focusses on the molecular and morphological variation among Scandinavian species within the Syntrichia ruralis complex (S. calcicola, S. norvegica, S. ruraliformis, S. ruralis) of the moss family Pottiaceae, plus the similar-looking S. princeps. Molecular variation was explored based on the internal transcribed spacer 1 (ITS1), and the plastid atpB-rbcL spacer and rpl16 G2 intron. The relationships of the S. ruralis complex taxa were evaluated by including twelve additional, morphologically defined Syntrichia species in the ingroup, including S. subpapillosissima that was here shown to occur in Scandinavia. The molecular evidence favours a wide circumscription of the S. ruralis complex, including the species around S. caninervis and some other ones but excluding S. princeps, and that these species are closely related. ITS1 paralogues were revealed in almost one-third of the samples, and for those cloned between 2 and 8 variants were found, including specimens with paralogues belonging to two (2 cases) or three (1) different species. Together with several cases of discrepancy between ITS1 and plastid relationships, this could suggest an exchange of genetic material between species and may explain the extensive and partly overlapping morphological variation among some of them. Syntrichia subpapillosissima and S. ruralis var. epilosa may represent special phenotypes within S. ruraliformis or S. ruralis, but studies of more material of these are required to decide their correct status.

Highlights

The genus Syntrichia Brid. in the family Pottiaceae includes around 90 species (Frey and Stech 2009), distributed almost all over the terrestrial world
The NeighborNet split networks for both internal transcribed spacer 1 (ITS1) and the plastid markers place the Scandinavian members of the S. ruralis complex and S. princeps firmly within Syntrichia (Fig. 1a)
Syntrichia handelii, S. latifolia, S. montana, S. rigescens, S. papillosissima, S. pseudohandelii, S. subpapillosissima, and S. virescens are closely related to the Scandinavian S. ruralis complex species, whereas S. laevipila, S. papillosa, S. princeps, and S. sinensis are more distantly related to this complex

Summary

Introduction

The genus Syntrichia Brid. in the family Pottiaceae includes around 90 species (Frey and Stech 2009), distributed almost all over the terrestrial world. The history of the genus is almost as long as that of moss nomenclature (for a review, see Gallego 2005). It was only with its typification (Zander 1989) and later use in the encyclopaedic overview of the Pottiaceae by Zander (1993) that the name Syntrichia became widely established in the 1990s for a group of species that had earlier mostly been included in Tortula Hedw.

Methods

Results

Conclusion