Search results for "Genetic diversity"

Parapatric diversification after post-glacial range expansion in the gall flyUrophora cardui(Tephritidae)

2010

Aim  Primary and secondary genetic clines in post-glacial colonized regions have different implications for biogeographic distributions and the origin of species. Primary clines arise in situ after colonization as adaptive responses to environmental gradients, while secondary clines are caused by contact between vicariant lineages. Here we analyse primary versus secondary origin of a genetic cline in the tephritid fly Urophora cardui in Jutland, Denmark, in a post-glacial landscape. Location  Western Palaearctic. Methods  Phylogeographic and demographic analyses of U. cardui based on mitochondrial DNA (mtDNA) genealogies, hierarchical genetic variance tests based on allozymes and distributi…

Population differentiation of the European pond turtle (Emys orbicularis) in Poland inferred by the analysis of mitochondrial and microsatellite DNA …

2013

We investigated the genetic diversity of Polish populations of the European pond turtle (Emys orbicularis) using complete sequences of the mitochondrial cytochrome b gene and allelic variation at thirteen microsatellite loci. We collected data from 146 turtles from 28 locations covering most of the species’ range in Poland. Our results showed a low haplotype diversity and high levels of microsatellite diversity in all populations. We applied two Bayesian approaches using the multilocus data and determined relationships of mtDNA haplotypes by constructing a parsimony network. We observed relatively consistent results of the two Bayesian clustering methods and largely concordant differentiati…

Population genetic study in the Balearic endemic plant speciesDigitalis minor(Scrophulariaceae) using RAPD markers

2001

Digitalis minor (Scrophulariaceae) is a cardenolide-producing plant endemic to the eastern Balearic Islands (Mallorca, Menorca, and Cabrera) that occurs in two morphologically distinct varieties: D. minor var. minor (pubescent) and D. minor var. palaui (glabrous). Levels and patterns of genetic diversity in 162 individuals from 17 D. minor populations across the entire geographic range were assessed using random amplified polymorphic DNA (RAPD) markers. Comigrating RAPD fragments tested were found to be homologous by Southern hybridization in both var. minor and var. palaui. To avoid bias in parameter estimation, analyses of population genetic structure were restricted to those RAPD bands t…

The voyage of an invasive species across continents: genetic diversity of North American and European Colorado potato beetle populations

2005

The paradox of successful invading species is that they are likely to be genetically depauperate compared to their source population. This study on Colorado potato beetles is one of the few studies of the genetic consequences of continent-scale invasion in an insect pest. Understanding gene flow, population structure and the potential for rapid evolution in native and invasive populations offers insights both into the dynamics of small populations that become successful invaders and for their management as pests. We used this approach to investigate the invasion of the Colorado potato beetle (Leptinotarsa decemlineata) from North America to Europe. The beetles invaded Europe at the beginnin…

Invasion success despite reduction of genetic diversity in the European populations of eastern mosquitofish (Gambusia holbrooki)

2006

The introduction of a few individuals to new, isolated habitats (founder effect) is expected to reduce the genetic variability of a population. At the beginning of the last century a few eastern mosquitofish (Gambusia holbrooki) individuals were introduced to Southern Europe from North America to control malaria‐carrying mosquitoes. We studied the effect of this severe bottleneck on genetic variability in four populations of eastern mosquitofish introduced to Spain and Italy in the early 1900s and compared them to a native population in North America. Using amplified polymorphic DNA–polymerase chain reaction (RADP–PCR) we found a strong reduction of genetic diversity, in terms of both numbe…

Genetic diversity in theCentaurea cinerariagroup (Compositae) in Sicily using isozymes

2006

Abstract The genetic diversity of seven taxa endemic to Sicily, C. cineraria, C. busambarensis, C. ucriae subsp. ucriae, C. ucriae subsp. umbrosa, C. todari, C. erycina and C. saccensis, from 11 localities was investigated using isozymes. Eight loci from five enzyme systems (IDH, MDH, PGD, PGM and PGI) were examined. A total of 19 alleles were identified, some rare and two of them exclusive to different populations. The allelic frequencies and the genetic variability values for each population were calculated. On the whole, the genetic diversity, i.e., average polymorphism (P) = 0.41, average number of alleles per locus (A) = 1.75, Nei's gene diversity (H) = 0.18, is moderate, with the high…

Continental-scale patterns of pathogen prevalence: a case study on the corncrake

2014

Pathogen infections can represent a substantial threat to wild populations, especially those already limited in size. To determine how much variation in the pathogens observed among fragmented populations is caused by ecological factors, one needs to examine systems where host genetic diversity is consistent among the populations, thus controlling for any potentially confounding genetic effects. Here, we report geographic variation in haemosporidian infection among European populations of corncrake. This species now occurs in fragmented populations, but there is little genetic structure and equally high levels of genetic diversity among these populations. We observed a longitudinal gradient…

Genetic diversity in the wild : cyclic population dynamics and population isolation

2013

Molecular phylogeny and ultrastructure of the lichen microalga Asterochloris mediterranea sp. nov. from Mediterranean and Canary Islands ecosystems

2015

The microalgae of the genus Asterochloris are the preferential phycobionts in Cladonia, Lepraria and Stereocaulon lichens. Recent studies have highlighted the hidden diversity of the genus, even though phycobionts hosting Cladonia spp. in Mediterranean and Canarian ecosystems have been poorly explored. Phylogenetic analyses were made by concatenation of the sequences obtained with a plastid -LSU rDNA- and two nuclear -ITS rDNA and actin- molecular markers of the phycobionts living in several populations of Cladonia convoluta-C. foliacea complex, C. rangiformis and C. cervicornis species widely distributed in these areas in a great variety of substrata and habitats. A new strongly supported …

Genetic Diversity of White Clover (Trifolium Repens L.) from the Urban Area of Rīga Baltā Āboliņa (Trifolium Repens L.) Ģenētiskā Daudzveidība Rīgas …

2015

Baltais āboliņš (Trifolium repens L.) ir tauriņziežu dzimtas augs, plaši izplatīts gan pilsētvidē, gan ārpus tās. Tas tiek izmantots kā lauksaimniecības augs biomasas iegūšanai, un tā ir arī populāra daudzgadīgos zālienus veidojošā suga - pilsētvidē balto āboliņu sēj zālājos. Baltais āboliņš plaši pārstāvēts dažādos biotopos ar mainīgu ārējo faktoru ietekmi, tai skaitā pilsētvidē. Tādēļ tas ir piemērots modeļobjekts antropogēnās ietekmes pētīšanai. Darba mērķis bija noteikt baltā āboliņa Latvijas populācijas ģenētisko daudzveidību, izmantojot iPBS (inter primer binding sites) - uz retrotranspazoniem balstītu metodi. Iegūtie rezultāti salīdzināti starp trim augu paraugkopām: pilsētvidē augoš…