Generic boundaries in subtribe Saussureinae (Compositae: Cardueae): Insights from Hyb‐Seq data

Abstract

The subtribe Saussureinae is a highly speciose group with more than 600 species distributed in the Northern Hemisphere and is particularly species‐rich at the high mountains of central and eastern Asia. Saussurea and Jurinea are the two main genera described within the subtribe. However, up to 15 satellite genera are recognized in some recent taxonomic treatments with an analytical viewpoint. For the first time, we carried out a complete sampling to clarify generic boundaries based on a well‐resolved phylogeny of Saussureinae. We employed a Hyb‐Seq technique that targets 1061 nuclear conserved ortholog loci designed for Compositae. After a filtering of potential paralogs, 588 loci were retained to infer phylogenetic trees under concatenation and coalescence approaches. High branch support resolution was recovered at the generic level, but a non‐monophyletic pattern was detected for most of the genera as they are currently circumscribed. Accordingly, we propose a new generic delimitation based on the three main clades recovered in the backbone tree, which are also in agreement with morphological evidence: Dolomiaea, Saussurea, and Jurinea. Following this classification into three genera, 18 new combinations are proposed. This new genus delineation will be used as a basis for future evolutionary studies in the Saussureinae.

A taxonomic revision of the genus Dolomiaea (Asteraceae: Cardueae) in India

“…(now known as subtribe Saussureinae). However, recent molecular work (Herrando-Moraira et al, 2020) has clearly shown that this species lies in the Dolomiaea clade. Also, detailed morphological investigation shows that it should belong to Dolomiaea rather than Jurinea due to the absence of scales on the receptacle and yellowish pappus bristles that are not inserted on a conic cupule in Dolomiaea as compared to the presence of short scales on the receptacle and white pappus bristles that are inserted on a conic cupule in Jurinea.…”

“…Therefore, Dolomiaea has been of great interest for systematists and has remained an integral part of the Saussurea -Jurinea group. However, recent studies have shown that Dolomiaea is a distinct genus and has been recovered as a well-supported 2 A taxonomic revision of Dolomiaea in India clade in molecular analyses (Wang et al, 2007;Herrando-Moraira et al, 2020;Kasana et al, 2020).…”

“…The genus Vladimiria Iljin was also included within the circumscription of Dolomiaea by Ling (1965) and was recognized as a section based on similarities in habit and inflorescence. Although the infrageneric limits within the present day subtribe Saussureinae have remained unclear for a long time (Susanna & Garcia-Jacas, 2009;Raab-Straube, 2017;Herrando-Moraira et al, 2020), grouping of genus Dolomiaea into two sections has been widely accepted (Chu, 1986;Wang et al, 2007): (i) D. sect. Dolomiaea characterized by short, compact style branches with round apex and (ii) D. sect.…”

“…Notes: With the advancement of molecular techniques, several phylogenetic studies (Wang et al, 2007;Susanna & Garcia-Jacas, 2009;Shen et al, 2020) have been carried out to investigate the systematic position of Dolomiaea and to assess its generic limits. In recent studies (Herrando-Moraira et al, 2020;Kasana et al, 2020) the genus has been re-circumscribed to include the genera Aucklandia Falc., Bolocephalus Hand.-Mazz. and Frolovia (DC.)…”

Jurinea Natmataungensis

“…Based on morphological evidence and phylogenetic analysis using Hyb-Seq data, generic delimitation in the subtribe Saussureinae was recently proposed for the three main clades, Dolomiaea DC., Saussurea, and Jurinea (Herrando-Moraira, 2020). As a result, all species of Himalaiella have been moved to Jurinea, which now consists of over 200 species, including unarmed dwarf shrubs, shrublets, and perennial herbs in Eurasia (Herrando-Moraira et al, 2020). Consequently, three species in Myanmar belong to Jurinea: J. deltoidea (DC.)…”