Uncovering the hidden diversity of the rosette‐forming Selaginella tamariscina group based on morphological and molecular data

Abstract

Plants of the Selaginella tamariscina group are common rosette-forming species showing great morphological variability across their distribution range. Integrating chloroplast genome data and morphological evidence, we studied the species delimitation within this group. We newly sequenced the complete chloroplast genomes of 53 individuals representing almost the entire geographical distribution of this group. Our phylogenetic analyses yielded a consistent topology dividing the S. tamariscina group into five major clades, which is further supported by principal component analysis of 18 morphological characters taken from 80 herbarium specimens. Based on the results of molecular analyses and morphological studies combined with the distribution information, we finally recognize five species in the S. tamariscina group, including two new species (S. algida sp. nov., S. graniticola sp. nov.), and one new subspecies (S. pulvinata subsp. qinbashanica subsp. nov.).

Integrative species delimitation of the Selaginella sanguinolenta (Selaginellaceae) group with description of a new species, S. baodongii

“…In the past years, the use of integrated taxonomic methods for plant species delimitation has gradually increased and successfully resolved species delimitation in different taxa (Li & al., 2019; Liang & al., 2019; Shao & al., 2020; M.H. Zhang & al., 2021; J. Yang & al., 2023).…”

“…Since morphological characters have long been used for species identification, the micromorphology of Selaginella species poses a great challenge to species delimitation (Shalimov & Zhang, 2021; M.H. Zhang & al., 2021; J. Yang & al., 2023).…”

“…The morphometric dataset was normalized using the function "scale = TRUE" to exclude the impact of different dimensions between features. Scatterplots were generated with the package ggplot2 v.3.4.0 (Wickham, 2016). We also performed a linear discriminant analysis (LDA) on the overall dataset, using the package MASS v.7.…”

Plastome-based Phylogenomic analyses provide insights into the germplasm resource diversity ofCibotiumin China

“…However, informative variation sites provided by these loci are too insufficient to illuminate the relationship within Chinese Cibotium . With the rapid development of next-generation sequencing (NGS) technologies, as well as advantages including low requirement of material quality, low costs and rich variable sites, chloroplast genome (plastome) has been used for phylogenetic reconstruction at different levels as well as species delimitation of closely related species in different plant lineages (e.g., Hammer et al, 2019; Wei and Zhang, 2020; Ji et al, 2021; Du et al, 2022; Xi et al, 2022; Zhang et al, 2022; Yang et al, 2023). Furthermore, plastomes can not only be applied to develop traditional DNA barcode but also used as a single genetic marker namely “ultra-barcode” (Nock et al, 2011; Kress et al, 2015; Hollingsworth et al, 2016), which largely benefits the identification of species or tissues lack of phenotypic divergence including products of medical plants (Park et al, 2021; Qin et al, 2022; Wang et al, 2022; Wei et al, 2022).…”

Rebuttal to “(2943) Proposal to conserve Selaginella, nom. cons., (Selaginellaceae) with a conserved type”: An unwarranted and disruptive idea

“…(2022), and Yang & al. (2022), who advocate the need to analyze a larger dataset, including nuclear and plastid data, and encourage undertaking a broader taxon sampling approach across species‐rich regions to explore the phylogeny of Selaginella to better understand and resolve relationships among closely related taxa and species complexes.…”