Evolution, ecology and systematics of Soldanella (Primulaceae) in the southern Apennines (Italy)

Abstract

BackgroundThe populations of Soldanella (Primulaceae) of the southern Apennines (Italy) are unique within the genus for their distribution and ecology. Their highly fragmented distribution range, with three main metapopulations on some of the highest mountains (Gelbison, Sila and Aspromonte massifs) of the area, poses intriguing questions about their evolutionary history and biogeography, and about the possibility of local endemisms.Aims and methodsIn order to clarify the phylogeny and biogeography of the three metapopulations of Soldanella in the southern Apennines, attributed to S. calabrella to date, and to identify possible local endemisms, a comparative approach based on the study of molecular, morphological and ecological characteristics of the populations was employed. Specifically, one nuclear (total ITS) and two plastid (rbcL and trnL) markers were used for the phylogenetic analyses, performed through both maximum likelihood and Bayesian techniques. Among the morphological features, the glandular hair and leaf biometric traits were analysed, and the environment in which the populations grew was characterised for altitude, forest canopy composition and soil pH, C, N and organic matter.Results and conclusionsOur findings demonstrate that the lineage of Soldanella of southern Italy diverged from the Carpathians lineage during the Middle Pleistocene, and underwent an evolutionary radiation during the Late Pleistocene. The populations of the Sila and Aspromonte massifs diverged from the populations of the Gelbison massif around 380000 years ago and are probably undergoing a progressive differentiation due to their isolation. The populations on the Gelbison massif, moreover, have different morphological features from those of the Sila and Aspromonte massifs and a different ecological niche. The molecular, morphological and ecological data clearly demonstrate that the metapopulation of Soldanella on the Gelbison massif belongs to a new taxonomic unit at the species level, which we name Soldanella sacra A. & L. Bellino from the name of the massif on which it was discovered, the “Holy Mountain”.Electronic supplementary materialThe online version of this article (doi:10.1186/s12862-015-0433-y) contains supplementary material, which is available to authorized users.

Karyological patterns in the European endemic genus Soldanella L.: Absolute genome size variation uncorrelated with cytotype chromosome numbers

“…Alpine biotopes are, however, inhabited also by two taxa morphologically belonging to the section Soldanella , namely, by S. alpina L. and S. rugosa L. B. Zhang (e.g., Pawłowska, 1972; Zhang and Kadereit, 2002; Steffen and Kadereit, 2014). Recent molecular investigations indicate that the sectional classification based on morphology and ecology is artificial and does not reflect true phylogenetic relationships within the genus (Zhang et al, 2001; Steffen and Kadereit, 2014; Bellino et al, 2015).…”

“…In total, we analyzed plant material from 299 individuals belonging to 110 populations (Table 1 and Appendix S1 [see the Supplemental Data with this article]). These populations covered all of the 24 recently accepted taxa, including those from Zhang's taxonomic concept as well as four newly described taxa (Zhang and Kadereit, 2002; Niederle, 2003, 2016; Bellino et al, 2015). To minimize misidentifications, almost all taxa were sampled at their type localities (Appendix S2).…”

“…Notes: a Classification of Soldanella species follows the taxonomic concepts proposed by Zhang and Kadereit (2002). Newly described taxa are marked by asterisks (Niederle, 2003, 2016; Bellino et al, 2015); b Number of individuals per population analyzed for AGS; c Variation range of AGS per species; and d Distribution ranges, habitat types, altitudinal vegetation types and altitudinal ranges are based on Zhang et al (2001) (herbarium survey) and authors’ field data. Observations contradicting reports published by Zhang and Kadereit (2002) are highlighted in bold.…”

“…Snowbells (the genus Soldanella L., Primulaceae) offer a good model for investigating karyological and AGS diversity at generic level, including evolution of rare cytotypes and their association with phenotypic and ecological variability. According to the current taxonomic concepts, the genus comprises 24 taxa (18 species and 6 subspecies), inhabiting various biotopes from midaltitudinal mountain forest to snow belt communities in the higher alpine belt of the major European mountain ranges (Pawłowska, 1972; Zhang et al, 2001; Zhang and Kadereit, 2002; Niederle, 2003, 2016; Marhold, 2011; Bellino et al, 2015). Members of this genus are some of the most studied European mountain plants, and a considerable interest has been devoted to their taxonomy, evolution, and biogeography (Pawłowska, 1972; Zhang et al, 2001; Zhang and Kadereit, 2002, 2004; Vargas, 2003; Niederle, 2003, 2016; Marhold, 2011; Steffen and Kadereit, 2014; de Vos et al, 2014; Bellino et al, 2015; Boucher et al, 2016).…”

“…According to the current taxonomic concepts, the genus comprises 24 taxa (18 species and 6 subspecies), inhabiting various biotopes from midaltitudinal mountain forest to snow belt communities in the higher alpine belt of the major European mountain ranges (Pawłowska, 1972; Zhang et al, 2001; Zhang and Kadereit, 2002; Niederle, 2003, 2016; Marhold, 2011; Bellino et al, 2015). Members of this genus are some of the most studied European mountain plants, and a considerable interest has been devoted to their taxonomy, evolution, and biogeography (Pawłowska, 1972; Zhang et al, 2001; Zhang and Kadereit, 2002, 2004; Vargas, 2003; Niederle, 2003, 2016; Marhold, 2011; Steffen and Kadereit, 2014; de Vos et al, 2014; Bellino et al, 2015; Boucher et al, 2016). In spite of this, our knowledge about karyological diversity of snowbells is largely incomplete and fragmentary (see e.g., Kress, 1969, 1984; Zhang and Kadereit, 2002; Anderberg, 2004; Rice et al, 2014).…”