Population cytotype structure and phenotypic variation of Campanula moravica

Polyploidizace je u rostlin významným evolučním procesem, který však často přináší taxonomické komplikace (stírání morfologických rozdílů mezi vyššími polyploidy). Komplikovaným polyploidním komplexem ve střední Evropě je i C. rotundifolia agg. V této skupině jsou v České republice tradičně odlišovány tři ploidně-variabilní druhy: C. gentilis (2x, 4x) C. rotundifolia (2x, 4x) a C. moravica (4x, 6x). V návaznosti na recentní revizi C. gentilis a C. rotundifolia se předložená diplomová práce zaměřila na zhodnocení karyologické a fenotypové variability druhu C. moravica v centru jeho areálu na území České republiky a Slovenské republiky. Pomocí moderních biosystematických metod (průtoková cytometrie, multivariační morfometrika) byly zjištěny značné nesrovnalosti mezi dosud publikovanými údaji o rozšíření cytotypů a morfologické variabilitě. Rozšíření cytotypů C. moravica je oproti původním údajům parapatrické, s hexaploidy rozšířenými převážně v Panonském termofytiku a tetraploidy zejména na středním a východním Slovensku. Typová populace domnělých tetraploidů se ukázala být hexaploidní. V jedné populaci na středním Slovensku byla zjištěna koexistence tetraploidů a šesti minoritních cytotypů (2x, 3x, 5x, 6x, 8x, 9x), což představuje dosud největší vnitropopulační ploidní variabilitu. Pomocí...Polyploidisation plays a major role in plant evolution. It can also cause taxonomic complexities as morphological differences are often blurred in higher ploidy levels. One of the taxonomically-intrigued groups of Central Europe is C. rotundifolia agg. Three ploidy- heterogeneous species are traditionally recognized in the Czech Republic: C. gentilis (2x, 4x), C. rotundifolia (2x, 4x) and C. moravica (4x, 6x). The thesis examines karyological and phenotypic variation of C. moravica, in the centre of its distribution (the Czech Republic and Slovakia). With the aid of modern biosystematics tools (DNA flow cytometry, multivariate morphometrics), marked discrepancies were revealed between published data and actual cytotype distribution pattern and morphological variation. In contrast to literature records, cytotype distribution in C. moravica is largely parapatric, with hexaploids occurring in Pannonian basin and tetraploids in Central and Eastern Slovakia. The type population of presumed tetraploids turned out to be hexaploid. The coexistence of one majority (4x) and six minority cytotypes (2x, 3x, 5x, 6x, 8x, 9x) was found in one population in central Slovakia and represent the most salient case of ploidy coexistence ever reported. Multivariate morphometrics showed that species identification on the...Department of BotanyKatedra botanikyFaculty of SciencePřírodovědecká fakult

Effect of whole-genome duplication on the evolutionary rescue of sterile hybrid monkeyflowers

Hybridisation is a creative evolutionary force, increasing genomic diversity, and facilitating adaptation and even speciation. Hybrids often face significant challenges to become established, including reduced fertility arising from genomic incompatibilities between their parents. Whole genome duplication in hybrids (allopolyploidy) can restore fertility, cause immediate phenotypic changes, and generate reproductive isolation. Yet the survival of polyploid lineages is uncertain, and few studies have compared the performance of recently formed allopolyploids and their parents under field conditions. Here we use natural and synthetically-produced hybrid and polyploid monkeyflowers (Mimulus spp.) to study how polyploidy contributes to the fertility, reproductive isolation, phenotype and performance of hybrids in the field. We find that polyploidisation restores fertility and that allopolyploids are reproductively isolated from their parents. The phenotype of allopolyploids displays the classic gigas effect of whole genome duplication, producing plants with larger organs and slower flowering. Field experiments indicate that survival of synthetic hybrids before and after polyploidisation is intermediate between the parents, whereas natural hybrids have higher survival than all the other taxa. We conclude that hybridisation and polyploidy can act as sources of genomic novelty, but adaptive evolution is key in mediating the establishment of young allopolyploid lineages

Cryptic invasion suggested by a cytogeographic analysis of the halophytic Puccinellia distans complex (Poaceae) in Central Europe

Introduction: Despite the wealth of studies dealing with the invasions of alien plants, invasions of alien genotypes of native species (cryptic invasions) have been vastly neglected. The impact of cryptic invasions on the biodiversity of plant communities can, however, be significant. Inland saline habitats and halophytes (i.e., salt-tolerant plant species) are especially threatened by this phenomenon as they inhabit fragmented remnants of largely destroyed habitats, but at the same time some of these halophytic species are rapidly spreading along salt-treated roads. To study potential cryptic invasion of halophytes, the patterns of genome size and ploidy variation in the Puccinellia distans complex (Poaceae), the most rapidly spreading roadside halophyte in Central Europe, were investigated. Methods: DNA flow cytometry with confirmatory chromosome counts were employed to assess ploidy levels of 1414 individuals from 133 populations of the P. distans complex. In addition, climatic niche modelling was used to predict the distributions of selected cytotypes. Results: Eight groups differing in ploidy level and/or genome size were discovered, one diploid (2x; 2n = 14), two tetraploid (4xA, 4xB; 2n = 28), one pentaploid (5x; 2n = 35), three hexaploid (6xA, 6xB, 6xC; 2n = 42), and one heptaploid (7x; 2n = 49). The hexaploids (mostly the 6xC cytotype) were widespread through the study area, spreading intensively in both anthropogenic and natural habitats and probably hybridizing with the natural habitat dwelling tetraploids. In contrast, the non-hexaploid cytotypes rarely spread and were predominantly confined to natural habitats. Discussion: The extensive spread of the hexaploid cytotypes along roadsides has most likely facilitated their incursion into natural habitats. The colonization of new natural habitats by the hexaploids may pose a threat to the indigenous Puccinellia populations by compromising their genetic integrity and/or by outcompeting them

Tempo and drivers of plant diversification in the European mountain system

There is still limited consensus on the evolutionary history of species-rich temperate alpine floras due to a lack of comparable and high-quality phylogenetic data covering multiple plant lineages. Here we reconstructed when and how European alpine plant lineages diversified, i.e., the tempo and drivers of speciation events. We performed full-plastome phylogenomics and used multi-clade comparative models applied to six representative angiosperm lineages that have diversified in European mountains (212 sampled species, 251 ingroup species total). Diversification rates remained surprisingly steady for most clades, even during the Pleistocene, with speciation events being mostly driven by geographic divergence and bedrock shifts. Interestingly, we inferred asymmetrical historical migration rates from siliceous to calcareous bedrocks, and from higher to lower elevations, likely due to repeated shrinkage and expansion of high elevation habitats during the Pleistocene. This may have buffered climate-related extinctions, but prevented speciation along elevation gradients as often documented for tropical alpine floras

Population structure and evolutionary history of Central European bellflowers from the Campanula rotundifolia agg.

6 Abstract For understanding extant species diversity, knowledge about processes acting at the population level is crucial. Besides mutations generating de novo genetic variation, three major processes, i.e., polyploidy, hybridization and local adaptation, notably impact population structure and cause evolutionary novelty. Campanula rotundifolia agg. was chosen as a model group for the joint study of these processes because it represents a polyploid complex with three major cytotypes (2x, 4x, 6x), a hitherto unknown ability to hybridize, and a pleiad of putative species that have undergone local adaptation to different conditions. In particular, polyploidization in the complex is acknowledged for generating morphological variation, facilitating long-distance dispersal and shifts in the environmental niche. It also creates a reproductive barrier, thus enabling sympatric speciation. Prerequisites for local adaptation are morphological variation and strong selection pressures leading to adaptive divergence and the rise of many endemic taxa, mainly at the extremes of environmental gradients. On the other hand, for locally adapted or endemic taxa, hybridization with a widespread taxon is one of the main existential threats. Here, I focused on C. rotundifolia agg. populations in Central Europe its hypothetical..

Populační struktura a evoluční historie středoevropských zvonků z okruhu Campanula rotundifolia agg.

6 Abstract For understanding extant species diversity, knowledge about processes acting at the population level is crucial. Besides mutations generating de novo genetic variation, three major processes, i.e., polyploidy, hybridization and local adaptation, notably impact population structure and cause evolutionary novelty. Campanula rotundifolia agg. was chosen as a model group for the joint study of these processes because it represents a polyploid complex with three major cytotypes (2x, 4x, 6x), a hitherto unknown ability to hybridize, and a pleiad of putative species that have undergone local adaptation to different conditions. In particular, polyploidization in the complex is acknowledged for generating morphological variation, facilitating long-distance dispersal and shifts in the environmental niche. It also creates a reproductive barrier, thus enabling sympatric speciation. Prerequisites for local adaptation are morphological variation and strong selection pressures leading to adaptive divergence and the rise of many endemic taxa, mainly at the extremes of environmental gradients. On the other hand, for locally adapted or endemic taxa, hybridization with a widespread taxon is one of the main existential threats. Here, I focused on C. rotundifolia agg. populations in Central Europe its hypothetical...7 Abstrakt zace novinky. Campanula rotundifolia agg.) byl vy studium a . polyploidizace zdroj komplexu a a ved k posunu klady pro i jsou k ke v hybridizace s V C. rotundifolia a alopatrii. a o na a tetraploid , a to jak v mi ami, studovala jsem morfologickou v v by variabilita ve velikosti genomu, v gneice a morfoligii. Vysok variabilita, s m vysok C. rotundifolia m ch ch model ne y rekonstruovanou , jsem porovnala genetickou a morfologickou variabilitu a variabilitu ve velikosti genomu u rostlin z C. rotundifolia s. str. Morfologick podobnost a genetick C. bohemica a C. scheuchzeri z Alp byl C. gelida ve v C. rotundifolia subsp. sudetica. Campanula rotundifolia subsp. sudetica C. rotundifolia s. str. Campanula rotundifolia fenotypovou taxonomy : Campanula rotundifolia agg,Katedra botanikyDepartment of BotanyFaculty of SciencePřírodovědecká fakult

Population structure and evolutionary history of Central European bellflowers from the Campanula rotundifolia agg.

6 Abstract For understanding extant species diversity, knowledge about processes acting at the population level is crucial. Besides mutations generating de novo genetic variation, three major processes, i.e., polyploidy, hybridization and local adaptation, notably impact population structure and cause evolutionary novelty. Campanula rotundifolia agg. was chosen as a model group for the joint study of these processes because it represents a polyploid complex with three major cytotypes (2x, 4x, 6x), a hitherto unknown ability to hybridize, and a pleiad of putative species that have undergone local adaptation to different conditions. In particular, polyploidization in the complex is acknowledged for generating morphological variation, facilitating long-distance dispersal and shifts in the environmental niche. It also creates a reproductive barrier, thus enabling sympatric speciation. Prerequisites for local adaptation are morphological variation and strong selection pressures leading to adaptive divergence and the rise of many endemic taxa, mainly at the extremes of environmental gradients. On the other hand, for locally adapted or endemic taxa, hybridization with a widespread taxon is one of the main existential threats. Here, I focused on C. rotundifolia agg. populations in Central Europe its hypothetical..

What we know about salty ecosystems of the Europe and their distribution, origin and history?

Salt marsh and meadow vegetation belong to very specific type of azonal ecosystem. There develop is made possible because of high concentrations of salts in the substrate. On the coast the development results from the contact of shore area with seawater. The existence of inland salt meadow is depending on specific climatic, geological and pedological conditions. Plants (halophytes) developed specific types of adaptation to resist high level of salinity and other extreme conditions of their habitat. During evolution occurred this type of adaptation in several phylogenetic lineages independently. Structure and physiognomy of salt marsh and meadow vegetation depend on the degree of salinity of the substrate and we can distinguish several zones on this gradient. Climatic conditions during the pleniglacial were very favourable for the development of halophyte vegetation. The oldest salt marshes, which played role of the refuge, are located on the coast, but also in the inland of Central Asia. This kind of vegetation reaches also south part of Central and Eastern Europe. After glaciation and the arrival of the forest, big part of this vegetation disappeared. Some inland areas have been maintained thanks to a man, which has used them since Neolithic times as pastures. With the abolition of grazing,..

What we know about salty ecosystems of the Europe and their distribution, origin and history?

Salt marsh and meadow vegetation belong to very specific type of azonal ecosystem. There develop is made possible because of high concentrations of salts in the substrate. On the coast the development results from the contact of shore area with seawater. The existence of inland salt meadow is depending on specific climatic, geological and pedological conditions. Plants (halophytes) developed specific types of adaptation to resist high level of salinity and other extreme conditions of their habitat. During evolution occurred this type of adaptation in several phylogenetic lineages independently. Structure and physiognomy of salt marsh and meadow vegetation depend on the degree of salinity of the substrate and we can distinguish several zones on this gradient. Climatic conditions during the pleniglacial were very favourable for the development of halophyte vegetation. The oldest salt marshes, which played role of the refuge, are located on the coast, but also in the inland of Central Asia. This kind of vegetation reaches also south part of Central and Eastern Europe. After glaciation and the arrival of the forest, big part of this vegetation disappeared. Some inland areas have been maintained thanks to a man, which has used them since Neolithic times as pastures. With the abolition of grazing,..

Population cytotype structure and phenotypic variation of Campanula moravica

Polyploidisation plays a major role in plant evolution. It can also cause taxonomic complexities as morphological differences are often blurred in higher ploidy levels. One of the taxonomically-intrigued groups of Central Europe is C. rotundifolia agg. Three ploidy- heterogeneous species are traditionally recognized in the Czech Republic: C. gentilis (2x, 4x), C. rotundifolia (2x, 4x) and C. moravica (4x, 6x). The thesis examines karyological and phenotypic variation of C. moravica, in the centre of its distribution (the Czech Republic and Slovakia). With the aid of modern biosystematics tools (DNA flow cytometry, multivariate morphometrics), marked discrepancies were revealed between published data and actual cytotype distribution pattern and morphological variation. In contrast to literature records, cytotype distribution in C. moravica is largely parapatric, with hexaploids occurring in Pannonian basin and tetraploids in Central and Eastern Slovakia. The type population of presumed tetraploids turned out to be hexaploid. The coexistence of one majority (4x) and six minority cytotypes (2x, 3x, 5x, 6x, 8x, 9x) was found in one population in central Slovakia and represent the most salient case of ploidy coexistence ever reported. Multivariate morphometrics showed that species identification on the..