High genetic diversity declines towards the geographic range periphery of Adonis vernalis, a Eurasian dry grassland plant

Abstract

Genetic diversity is important for species' fitness and evolutionary processes but our knowledge on how it varies across a species' distribution range is limited. The abundant centre hypothesis (ACH) predicts that populations become smaller and more isolated towards the geographic range periphery - a pattern that in turn should be associated with decreasing genetic diversity and increasing genetic differentiation. We tested this hypothesis in Adonis vernalis, a dry grassland plant with an extensive Eurasian distribution. Its life-history traits and distribution characteristics suggest a low genetic diversity that decreases and a high genetic differentiation that increases towards the range edge. We analysed AFLP fingerprints in 28 populations along a 4698-km transect from the geographic range core in Russia to the western range periphery in Central and Western Europe. Contrary to our expectation, our analysis revealed high genetic diversity (range of proportion of polymorphic bands = 56-81%, He = 0.168-0.238) and low genetic differentiation across populations (Φ(ST) = 0.18). However, in congruence with the genetic predictions of the ACH, genetic diversity decreased and genetic differentiation increased towards the range periphery. Spanish populations were genetically distinct, suggesting a divergent post-glacial history in this region. The high genetic diversity and low genetic differentiation in the remaining A. vernalis populations is surprising given the species' life-history traits and points to the possibility that the species has been widely distributed in the studied region or that it has migrated from a diverse source in an East-West direction, in the past.

Genetic structure and diversity of Adonis L. (Ranunculaceae) populations collected from Turkey by inter-primer binding site (iPBS) retrotransposon markers

“…Dichogamy function is supported by different (biological and morphological) mechanisms, and in this way, cross-fertilization is provided in this family, which increases genetic diversity (Denisow et al, 2014) within the population. Similar findings were reported for other plants, such as A. vernalis (Hirsch et al, 2015), A. aestivalis (Meyer et al, 2015), Ajowan (Heidari et al, 2016), Nigella sativa (Birhanu et al, 2015), and Falcaria vulgaris (Piya et al, 2014).…”

“…In a more recent study of Adonis sp., the percentage of polymorphism was 56%-81% for A. vernalis based on the AFLP marker (Hirsch et al, 2015). The PIC value ranged from 0.16 (iPBS 2276) to 0.39 (iPBS 2385), with an average of 0.30 (Table 3).…”

“…For example, Suh et al (2002) reported a total of 91 polymorphic bands for 60 individuals from 12 Korean Adonis populations using 12 arbitrary RAPD primers. In another study that utilized AFLP loci, the number of polymorphic bands was 393 among 163 A. aestivalis individuals, with an average of 2.41 polymorphic bands per species (Hirsch et al, 2015).…”

“…Morphological (Son and Ko, 2013), ecological (Erfanzadeh et al, 2013), palynological (Fernández and Sánchez, 1988), and genetic diversity (Ro et al, 1997;Suh et al, 2002;Boronnikova and Kalendar, 2010;Kalendar et al, 2010) studies on the genus Adonis have been undertaken in various regions of the world. However, to date, in Adonis there has been limited research regarding the use and development of molecular markers such as random amplified polymorphic DNA (Suh et al, 2002) and amplified fragment length polymorphism (Hirsch et al, 2015;Meyer et al, 2015).…”

Assessment of current genetic structure from local to geographic scales indicates brake down of historically extensive gene flow in the dry grassland species Scabiosa canescens Waldst. & Kit. (Dipsacaceae)

“…Current evidence suggests that S. canescens originated from the Mediterranean during the Pleistocene climatic fluctuations (Carlson, Linder, & Donoghue, 2012), and consequently colonized Germany from the south. Because populations towards the altitudinal and latitudinal range margins occur naturally at lower densities, have distinct local adaptations and potentially a more recent colonization history, they naturally can have lower genetic diversity (Hirsch et al, 2015;Vucetich & Waite, 2003). Although genetically less diverse, these populations might contribute substantially to the overall genetic diversity of species (Lesica & Allendorf, 1995).…”