Publications by authors named "Andrea Melicharkova"

Specific ecological conditions in the high mountain environment exert a selective pressure that often leads to convergent trait evolution. Reticulations induced by incomplete lineage sorting and introgression can lead to discordant trait patterns among gene and species trees (hemiplasy/xenoplasy), providing a false illusion that the traits under study are homoplastic. Using phylogenetic species networks, we explored the effect of gene exchange on trait evolution in Soldanella, a genus profoundly influenced by historical introgression.

View Article and Find Full Text PDF

Elucidating the evolution of recently diverged and polyploid-rich plant lineages may be challenging even with high-throughput sequencing, both for biological reasons and bioinformatic difficulties. Here, we apply target enrichment with genome skimming (Hyb-Seq) to unravel the evolutionary history of the Alyssum montanum-A. repens species complex.

View Article and Find Full Text PDF

Hybridization is a key mechanism involved in lineage diversification and speciation, especially in ecosystems that experienced repeated environmental oscillations. Recently radiated plant groups, which have evolved in mountain ecosystems impacted by historical climate change provide an excellent model system for studying the impact of gene flow on speciation. We combined organellar (whole-plastome) and nuclear genomic data (RAD-seq) with a cytogenetic approach (rDNA FISH) to investigate the effects of hybridization and introgression on evolution and speciation in the genus Soldanella (snowbells, Primulaceae).

View Article and Find Full Text PDF

The Mediterranean Basin is a significant hotspot of species diversity and endemism, with various distribution patterns and speciation mechanisms observed in its flora. High species diversity in the Mediterranean is also manifested in the monophyletic lineage of annuals (Brassicaceae), but little is known about its origin. These species include both diploids and polyploids that grow mainly in open and disturbed sites across a wide elevational span and show contrasting distribution patterns, ranging from broadly distributed Eurasian species to narrow island endemics.

View Article and Find Full Text PDF

Recurrent polyploid formation and weak reproductive barriers between independent polyploid lineages generate intricate species complexes with high diversity and reticulate evolutionary history. Uncovering the evolutionary processes that formed their present-day cytotypic and genetic structure is a challenging task. We studied the species complex of , composed of diploid endemics in the European Mediterranean and diploid-polyploid lineages more widely distributed across Europe, focusing on the poorly understood variation in Central Europe.

View Article and Find Full Text PDF

We investigated ochratoxin A (OTA) contamination in raisin samples purchased from Slovak markets and determined the diversity of black-spored aspergilli as potential OTA and fumonisin (FB1 and FB2) producers. The taxonomic identification was performed using sequences of the nuclear ITS1-5.8s-ITS2 region, the calmodulin and beta-tubulin genes.

View Article and Find Full Text PDF

Genetic patterns of lichenized fungi often display a mosaic-like and difficult to interpret structure blurring their evolutionary history. The genetic diversity and phylogeographic pattern of a mycobiont of the predominantly Mediterranean dwelling lichen Solenopsora candicans were investigated on the base of extensive sampling (361 individuals, 77 populations) across its entire distribution range. We tested whether the genetic pattern of S.

View Article and Find Full Text PDF
Article Synopsis
  • The study focuses on Alyssum repens, a mountain plant with disjunct distributions in the SE Alps and Carpathians, examining its genetic and cytotype structure.
  • The researchers used various genetic and morphometric methods to investigate the species' lineage and polyploid origins, discovering four distinct genetic lineages across different geographical areas.
  • Despite some genetic differentiation suggesting potential species splitting, the researchers recommend maintaining Alyssum repens as one variable species due to limited morphological differences among the lineages.
View Article and Find Full Text PDF
Article Synopsis
  • * The genus Picris L. serves as an example to study this dynamic, with ancestral traits indicating its origins in North Africa and West Asia, showing significant speciation changes linked to environmental shifts around 1 million years ago.
  • * Findings reveal that traits like fruit type and life cycle strategies (semelparity vs. iteroparity) influence species distribution and diversification, highlighting the importance of both intrinsic traits and environmental predictability in large-scale colonization events.
View Article and Find Full Text PDF

Goals: To test the hypothesis that the use of a low-residue breakfast (LRB) the day prior to colonoscopy was not inferior to consuming clear fluids alone (CFD) in patients undergoing outpatient colonoscopy with a polyethylene glycol (PEG) bowel preparation.

Background: Optimal colon cleansing is essential for complete visualisation of the mucosa during colonoscopy. Few studies have examined the effect of diet on the quality of bowel cleansing or tolerance in patients using a PEG bowel preparation for colonoscopy.

View Article and Find Full Text PDF

Objectives: We compared the efficacy and patient tolerance of two dietary regimens used as an adjunct to standard bowel cleansing in preparation for elective colonoscopy.

Methods: Our prospective, randomized, single-blind, controlled, noninferiority trial compared two dietary regimens administered the day before colonoscopy. Subjects received low-volume bowel preparation.

View Article and Find Full Text PDF