Evolution in the Model Genus Antirrhinum Based on Phylogenomics of Topotypic Material

Abstract

Researchers in phylogenetic systematics typically choose a few individual representatives of every species for sequencing based on convenience (neighboring populations, herbarium specimens, samples provided by experts, garden plants). However, few studies are based on original material, type material or topotypic material (living specimens from the locality where the type material was collected). The use of type or topotypic material in phylogenetic studies is paramount particularly when taxonomy is complex, such as that of Antirrhinum (Plantaginaceae). In this paper, we used topotypic materials of Antirrhinum at the species level (34 species proposed by previous authors), 87 specimens representing the species distributions and >50,000 informative nucleotide characters (from ∼4,000 loci) generated by the genotyping-by-sequencing (GBS) technique: (i) to test two explicit taxonomic hypotheses widely followed by local taxonomic treatments; (ii) to robustly estimate phylogenetic relationships; (iii) to investigate the evolution of key morphological characters and biogeographic centers of differentiation. Two GBS phylogenies based on two datasets (87 localities and 34 topotypic specimens) revealed that: (1) Sutton’s (1988) taxonomic account is the most congruent with phylogenetic results, whereas division of Antirrhinum into three major clades disagrees with Rothmaler’s (1956) infrageneric classification; (2) monophyly of populations currently included in the same species is primarily supported; (3) the historically recognized Antirrhinum majus group is not monophyletic; (4) sister-group relationships are robust for eight species pairs; (5) the evolutionary radiation of 26 species since the Pliocene is underpinned given a high rate of diversification (0.54 spp. Myr–1); (6) a geographic pattern of speciation is reconstructed, with northern Iberia as the center of early diversification followed by more recent speciation in southeastern Iberia; and (7) multiple acquisitions of key taxonomic characters in the course of Antirrhinum diversification are strongly supported, with no evidence of hybridization between major clades. Our results also suggest incipient speciation in some geographic areas and point to future avenues of research in evolution and systematics of Antirrhinum.

Reticulate Evolution in the Western Mediterranean Mountain Ranges: The Case of the Leucanthemopsis Polyploid Complex

“…This was done to include all taxa described by Heywood (1975) and Pedrol (2019), and to incorporate, when possible, material from loci classici or herbarium vouchers cited in the above-mentioned revisions. The importance of including topotypic material in phylogenetic studies involving intricate taxonomic groups has already been highlighted in other studies (Otero et al, 2021). A complete list of samples used in the present study is provided in the Supplementary Data Sheet 1.…”

El endemismo bético-rifeño Antirrhinum australe, novedad corológica para la provincia de Sevilla

“…Por otro lado, es bien conocida la estrecha relación de parentesco evolutivo existente entre A. australe y A. tortuosum Bosc ex Vent. (Wilson & Hudson 2011;Otero et al 2021), hasta el extremo de que algunos autores argumentan que constituyen una misma entidad biológica (Mateu-Andrés & de Paco 2005). Los rasgos que acostumbran a definir a una especie frente a otra son la morfología foliar, la pilosidad de sus órganos aéreos y el tamaño de la corola (Rothmaler 1956, Sutton 1988, Güemes 2009.…”

“…ex Ficalho) Rothm. es otra especie que mantiene gran similitud con A. australe, aunque su parentesco evolutivo no es tan estrecho como con la anterior (Otero et al 2021). A pesar de que habita típicamente en dunas litorales, también ha sido citada de la provincia de Sevilla (Ruiz de Clavijo & al.…”

Non‐reproducible signals of adaptation to elevation between open and understorey microhabitats in snapdragon plants

“…Snapdragon plants harbour either magenta or yellow flowers, which can be used to distinguish between the two interfertile subspecies A. m. pseudomajus and A. m. striatum respectively (Andalo et al, 2010;Durán-Castillo et al, 2021). These subspecies are not always recognized by taxonomists (Sutton, 1988) but widely acknowledged by population and evolutionary biologists (Durán-Castillo et al, 2021;Liberal et al, 2014;Otero et al, 2021). They are distributed parapatrically (Khimoun et al, 2011) As illustrated on Figure 1, the geographic range of A. m. striatum is surrounded by the range of A. m. pseudomajus (Khimoun et al, 2013).…”