Elucidating cryptic sympatric speciation in terrestrial orchids

Abstract

RUNNING READ: Cryptic sympatric speciation in orchids ABSTRACT PREMISE: Cryptic sympatric speciation occurs when closely related species arises with no geographic or spatial isolation. Since cryptic species can not usually be detected when investigations are based exclusively on classical plant taxonomy, molecular markers and integrative taxonomy are important tools to elucidate the identity of cryptic taxa. METHODS:In this paper we aimed to provide a detailed investigation based on molecular data and experimental taxonomy conducted on populations of a plant model occurring inside mesophytic forests and a supposed cryptic sympatric species that is found in marshy areas. Furthermore, a phylogeny was reconstructed by using nrDNA and cpDNA sequences in order to ascertain the position of both sympatric species within Liparis. The divergence among sequences of the putative cryptic sympatric species and related taxa was also verified based on DNA barcoding. KEY RESULTS:Our results reveal cryptic sympatric speciation in the orchid genus Liparis. Differences in microhabitat, flowering phenology, morphology of leaves and flowers, and reproductive strategies support the taxon occurring in marshy areas is a cryptic species. The molecular analyses reveal the cryptic species is closely related to L. nervosa. CONCLUSIONS: PaludalLiparis is a sympatric cryptic species distinguishable from L. nervosa by differences in habitat, phenology and breeding system. Our conclusions are supported by the molecular investigations. The cryptic Liparis emerges as sister to L. nervosa, within a clade with terrestrial habitat and plicate leaves. The discovery of sympatric cryptic speciation in orchids provides increase on the knowledge of diversification and reproductive isolation in flowering plants.

Drivers of population divergence and species differentiation in a recent group of indigenous orchids (Vanilla spp.) in Madagascar

“…Evolutionary patterns can be quite complex in plants (Lowry et al., 2008; Waser & Campbell, 2004), particularly in Orchidaceae. Indeed, orchid species evolve occasionally in sympatry (Barone Lumaga et al., 2012; Nielsen & Siegismund, 1999; Pansarin & Ferreira, 2019), produce numerous seeds with long‐range dispersal ability (Arditti & Ghani, 2000), can reproduce clonally (Batygina et al., 2003), and hybridize (Arduino et al., 1996; Nielsen & Siegismund, 1999). Potential ecological drivers of orchid diversification are multiple, such as adaptation to pollinators (Ayasse et al., 2011; Dressler, 1982; Van der Niet et al., 2014), mycorrhizal specificity (Otero et al., 2007), differences in flowering phenology, and floral characteristics (color, form and fragrance) resulting from adaptation to different environmental conditions (Givnish et al., 2015; Pansarin & Ferreira, 2019; Sun et al., 2015) and leading to isolation by ecology.…”

“…Indeed, orchid species evolve occasionally in sympatry (Barone Lumaga et al., 2012; Nielsen & Siegismund, 1999; Pansarin & Ferreira, 2019), produce numerous seeds with long‐range dispersal ability (Arditti & Ghani, 2000), can reproduce clonally (Batygina et al., 2003), and hybridize (Arduino et al., 1996; Nielsen & Siegismund, 1999). Potential ecological drivers of orchid diversification are multiple, such as adaptation to pollinators (Ayasse et al., 2011; Dressler, 1982; Van der Niet et al., 2014), mycorrhizal specificity (Otero et al., 2007), differences in flowering phenology, and floral characteristics (color, form and fragrance) resulting from adaptation to different environmental conditions (Givnish et al., 2015; Pansarin & Ferreira, 2019; Sun et al., 2015) and leading to isolation by ecology. Although the various patterns namely IBD, IBE, and IBA have gained attention in the literature (e.g., Garot et al., 2019; Liu et al., 2018; Noguerales et al., 2016; Orsini et al., 2013; Shafer & Wolf, 2013), few studies have evaluated their joint contribution in orchid species differentiation (e.g., Jaros et al., 2016; Mallet et al., 2014), and no research efforts, to our knowledge, have been invested so far on this subject regarding Vanilla species divergence.…”

Integrative taxonomy and phylogeny of leafless Vanilla orchids from the South‐West Indian Ocean region reveal two new Malagasy species

“…By combining different species concepts, the limitations of each species concept are offset by the advantages of the others, making integrative taxonomy a now widely used approach (Dayrat, 2005). Hence, integrative taxonomy has been shown as being most efficient for the delimitation of recently diverged, cryptic or closely related species (e.g., Dayrat, 2005; Duminil et al, 2012; Pessoa et al, 2012; Pansarin & Ferreira, 2019).…”