Genetic variation in the allotetraploid Dryopteris corleyi (Dryopteridaceae) and its diploid parental species in the Iberian Peninsula

Abstract

Studies on genetic diversity help us to unveil the evolutionary processes of species and populations and can explain several traits of diploid-polyploid complexes such as their distributions, their breeding systems, and the origin of polyploids. We examined the allozyme variation of Dryopteris aemula and D. oreades, diploid ferns with highly fragmented habitats, and the allotetraploid D. corleyi to (1) analyze the putative relationship between both diploids and the tetraploid, (2) compare the levels of genetic variation among species and determine their causes, and (3) assess the breeding system of these taxa. The allozymic pattern of D. corleyi confirms that it derived from D. aemula and D. oreades. The lack of genetic diversity in D. aemula, a species of lowland habitats, may be due to genetic drift associated with the contraction of populations in the last glaciation. By contrast, the alpine D. oreades had moderate intrapopulation genetic variation, which may derive from the expansion of populations during the last glaciation. In the latter species, low interpopulational variation suggested effective gene flow (spore exchange), and genotype frequencies in Hardy-Weinberg equilibrium indicated cross-fertilization of gametophytes. Evolutionary history appears to be an essential element in the interpretation of genetic variation of highly fragmented populations.

Molecular circumscription and major evolutionary lineages of the fern genus Dryopteris (Dryopteridaceae)

“…Variae ; our Variae clade) [59]. Using allozyme data Jiménez et al [60] concluded that D. corleyi , an endemic of northern Spain, is of hybrid origin between D. aemula ( D. sect. Aemulae ) and D. oreades Fomin ( D. sect.…”

“…This is not surprising because D. corleyi , an endemic of northern Spain, is thought to be of hybrid origin between D. aemula ( D. sect. Aemulae ) and D. oreades Fomin based on allozyme data ([60]; see below). All three species of D. sect.…”

Profundizando en la evolución de los helechos: un enfoque mecanicista a los principales conceptos y técnicas de estudio

“…Isozyme markers allowed much more accumulation of genetic insights to understand the mating system and consequences of outcrossing as a main mechanism favou-ring intergametophytic mating in the main homosporous fern lineages, in contrast to previous inbreeding assumptions (Soltis & Soltis 1990, Jiménez et al 2009, Yatabe et al 2009). In the decade of 1980 morphological discrimination of hybrids was improved with quantitative analysis of morphometric characters.…”

“…In some Dryopteris Adans. complexes studies are inconclusive and, for many allopolyploids, the question remains unresolved (Jiménez et al 2009, Stein et al 2010, Sessa et al 2012a.…”

What We Do (and Don't) Know About Ferns: <I>Dryopteris</I> (Dryopteridaceae) as a Case Study

“…Jiménez and colleagues have explored genetic diversity between polyploids and diploids in the D. aemula (Aiton) Kuntze group (Jiménez et al 2008(Jiménez et al , 2009(Jiménez et al , 2010, and Ekrt and colleagues (2010) used genome size to study species delimitation in the D. carthusiana complex. Phylogenetic analyses using nuclear locus pgiC have clari- …”