Ploidy as a leaky reproductive barrier: mechanisms, rates and evolutionary significance of interploidy gene flow.

Background: Whole-genome duplication (polyploidization) is a dominant force in sympatric speciation, particularly in plants. Genome doubling instantly poses a barrier to gene flow owing to the strong crossing incompatibilities between individuals differing in ploidy. The strength of the barrier, however, varies from species to species and recent genetic investigations revealed cases of rampant interploidy introgression in multiple ploidy-variable species.

Polyploidization as an opportunistic mutation: The role of unreduced gametes formation and genetic drift in polyploid establishment.

It is broadly assumed that polyploidy success reflects an increase in fitness associated with whole-genome duplication (WGD), due to higher tolerance to stressful conditions. Nevertheless, WGD also arises with several costs in neo-polyploid lineages, like genomic instability, or cellular mis-management. In addition to these costs, neo-polyploid individuals also face frequency dependent selection because of frequent low-fitness triploids formed by cross-ploidy pollinations when tetraploids are primarily rare in the population.

Genetic similarities versus morphological resemblance: Unraveling a polyploid complex in a Mediterranean biodiversity hotspot.

The Balkan Peninsula is recognized as one of the hotspots of biodiversity in Europe. This area has shown since the Last Glacial Maximum appropriate conditions for species diversification and hybridization, which has led to the existence of numerous taxonomically unresolved entities. Here, we focus on the Western Balkans and explore the genetic structure and relationships among species belonging to the V.

Environmental differences are correlated with the distribution pattern of cytotypes in Veronica subsection Pentasepalae at a broad scale.

Background And Aims: The distribution of cytotypes and its potential correlation with environmental variables represent a cornerstone to understanding the origin and maintenance of polyploid lineages. Although many studies have addressed this question in single species at a regional scale, only a few have attempted to decipher this enigma in groups of closely related species at a broad intercontinental geographical scale. Here, we consider approx.

Microsatellite marker development for the tetraploid (Plantaginaceae) using next-generation sequencing and high-resolution melting analyses.

Premise Of The Study: The tetraploid (Plantaginaceae) is a narrow endemic to the Iberian Peninsula. Specific microsatellite markers were developed to investigate genetic structure and diversity.

Methods And Results: A total of 15 polymorphic markers were characterized on three populations of , using a microsatellite-enriched library on an Ion Torrent sequencer and high-resolution melting (HRM) analyses to rapidly discard nonreliable, multicopy, and/or monomorphic loci.

The challenge of species delimitation in the diploid-polyploid complex Veronica subsection Pentasepalae.

A reliable taxonomic framework and the identification of evolutionary lineages are essential for effective decisions in conservation biodiversity programs. However, phylogenetic reconstruction becomes extremely difficult when polyploidy and hybridization are involved. Veronica subsection Pentasepalae is a diploid-polyploid complex of ca.