Re-establishment of species from synonymies based on DNA barcoding and phylogenetic analysis using Diplopterygium simulans (Gleicheniaceae) as an example

Abstract

Because synonymy treatment traditionally relies on morphological judgments, it usually causes many problems in species delimitation and in the biodiversity catalogue. For example, Diplopterygium simulans, which belongs to the Gleicheniaceae family, has been considered to be synonymous with D. glaucum or D. giganteum based mainly on the morphology of its pinna rachis and blade. In the absence of molecular evidence, these revisions remain doubtful. DNA barcoding, which is considered to be a powerful method for species-level identification, was employed to assess the genetic distance among 9 members of the Diplopterygium genus. The results indicate that D. simulans is an independent species rather than a synonymy of D. glaucum or D. giganteum. Moreover, phylogenetic analysis uncovered the sisterhood of D. simulans and D. cantonense, which is supported by their geographical distributions and morphological traits. Incorrect synonymy treatment is prevalent in the characterization of biological diversity, and our study proposes a convenient and effective method for validating synonym treatments and discovering cryptic species.

Phylogenomic Analysis Reconstructed the Order Matoniales from Paleopolyploidy Veil

“…In the extant lycopods and ferns, more than 40 valid orders were reported, but only 14 of these are accepted in PPG I [20,63]. However, more careful studies may be required to verify the treatments of these synonym names in the future [78]. In this study, as an example, we have reconstructed the new order Matoniales from the synonym names with phylogenomic analysis, which was opposed to previous treatments.…”

Dryopteris wulingshanensis (Dryopteridaceae), a new species from Hunan, China

“…Total genomic DNA was extracted from silica gel-dried leaves by using a DNA secure Plant Kit (Tiangen Biotech, Beijing, China) according to the manufacturer’s protocols. The primers and amplification reaction of rbc L gene followed the protocols of Shu et al (2017) . Sequencing reactions were set up to obtain both the forward and reverse sequences, and then sequenced on an ABI 3730xl DNA Analyzer (Applied Biosystems, Foster City, California, USA).…”

Finding missing diversity from synonyms of Haplopteris (Pteridaceae)

“…For instance, International Plant Names Index (IPNI 2020) provides information on nomen novum, combination nova, and taxa nova, but it provides no information on new species resurrected from the established synonyms. Although many species of ferns (Liu et al 2013;Morigengaowa et al 2018;Shu et al 2017;Shu et al 2018;Sigel et al 2014;Wang et al 2020;Wei et al 2018) and seed plants (Tkach et al 2015;Hu et al 2015) have been reinstated as independent species, this type of study has been rarely reported. The extent of biodiversity hidden in taxonomic literature is an interesting question to explore.…”

“…Unfortunately, once a species name is treated as a synonym, it remains in the pile of synonyms forever. With the development in molecular phylogeny research, DNA barcoding, and detailed taxonomic observations, an increasing number of species names have been re-established from the checklist of synonyms, which ranges from ferns ( Shu et al 2017 ; Shu et al 2018 ; Wei et al 2018 ; Wang et al 2020 ) to spermatophyte ( Luo et al 2016 ; Jin et al 2017 ; Wang et al 2018 ). Consequently, we found that the synonym database could be a new hotspot for biodiversity discovery.…”