Perhaps all orchids are mycotrophic at early developmental stages, while majority of species photosynthesize at adulthood and only about 200 species remain fully mycotrophic for the whole life. Mycotrophy affects orchids at many levels. In this thesis, I focus on four aspects of orchid biology, which could be connected with mycotrophy: (i) systematics, (ii) genome size and endoreduplication, (iii) regulation of seed germination and (iv) mechanism of transfer of carbon and energy from fungi to orchids. There are over 27,000 recently recognized orchid species, nevertheless new ones are still discovering and old ones are revisiting. In this work I present a description of new species, Cleisostoma yersinii, and its morphological, anatomical, ecological and systematic characterization. Phylogeny reconstruction confirmed relationship with C. birmanicum. In the subtribe Podochileae, I reappraised the genus Campanulorchis to establish monophyletic but also morphologically defined group. For both abovementioned genera I prepared the artificial identification key. In the genus Dactylorhiza I revised taxa present in our country and I prepared an identification key which firstly mentions D. maculata subsp. elodes from Czech Republic. Orchid species diversity is probably reflected in genome structure. Results...

Considerable variation exists both within and between species in nuclear DNA content. Despite there being no obvious functional role for much of this DNA, many studies have reported phenotypic correlations with genome size at various taxonomic levels. This suggests that DNA plays a functional role beyond the traditionally understood mechanisms. One such example of a phenotypic correlation with DNA content is present in the genus Silene, where a negative correlation between DNA content and flower size exists within and between species. This relationship is consistent with the direction of sexual dimorphism in DNA content (caused by heteromorphic sex-chromosomes) and flower size in the most studied species in the genus: S. latifolia. This thesis takes a comparative approach between two closely related species in the genus (S. latifolia and S. marizii), which differ markedly in their nuclear DNA content, in order to investigate the nature and phenotypic impacts of variation in DNA content. A phenotypic survey from a number of S. marizii populations reveals that the pattern of DNA content variation in this species is very different to that in S. latifolia. In particular, phenotypic correlations with DNA content appear be much weaker, whilst sexual dimorphism in DNA content, when present, appears to occur in either direction. A survey of interspecific hybrids suggests that this may be due to an enlarged S. marizii X-chromosome and that DNA content in hybrids may be biased with regard to their parents. Repetitive elements may be significant constituents of plant genomes. A study of Ty1-copia class retrotransposons in the two species reveals that they are present as a large and highly heterogeneous population. Phylogenetic analysis of these elements suggests a substantial degree of genetic isolation between the two species. Finally, an assessment of the flow-cytometric method, used to estimate DNA content, reveals substantial error associated with the method, but only limited evidence for stoichiometric effects.

This thesis deals with interspecific hybridization in sympatric populations of Pulsatilla patens and P. pratensis. The key aim was to assess karyological and phenotypic variation in the study group. DNA flow cytometry revealed three non-overlapping groups of genome sizes, corresponding to P. patens, P. × hackelii and P. pratensis. The frequency of interspecific hybridization was low, accounting to approx. 3% of analyzed plants. Morphometric analyses identified a set a reliable species-specific characters, including number of divisions the leaf, length of petiole the part of leaf, number of smaller parts of leaf and colour of blossom. Although the majority of hybrid individuals flowered and set fruits, their fertility was reduced considerably. The threat from interspecific hybridization to parental species is therefore rather low.

La conservation au niveau population est extrêmement nécessaire pour limiter la perte de biodiversité au sein d'une espèce ou d'un complexe d'espèces. Ainsi, l'évaluation de la variabilité inter-populationnelle dans le complexe est reconnue comme première étape importante pour bien définir les plans de conservation des espèces menacées. Arenaria grandiflora form un complexe d'espèces herbacées pérennes à courte durée de vie (4 ans en moyenne) menacé dans certains sites de ses zones de distribution en Europe. A ce jour, sa taxonomie n'est pas bien résolue, ce qui entraîne des problèmes potentiels pour mettre en oeuvre une conservation efficace de ce taxon. Une variation inter-populationnelle du complexe d'espèces A. grandiflora est présentée dans cette étude aux niveaux génétiques, cytogénétiques et morphométriques. Quatre méthodes ont été utilisées : des marqueurs microsatellites nucléaires, une approche cytogénétique, la cytométrie en flux, et enfin la morphométrie sur les feuilles. De plus, les études phénotypiques de variation de taux de germination entre stocks de graines ont été développées. Une différenciation significative entre les profils de variations moléculaires, cytogénétiques et phénotypiques a été détectée dans le complexe d'espèces. Deux cytotypes (diploïdes 2n=2x=22 et tétraploïdes 2n = 4x = 44) ont été mis en évidence en utilisant à la fois des méthodes classiques et des méthodes plus récentes (marqueurs microsatellites, nombres chromosomiques et cytométrie de flux). Le complexe d'espèces d'A; grandiflora présente une forte variation de la valeur de l'ADN 2C, la taille du génome varie de 2.11 ± 0.74 pg à 2.70 ± 0.11 pg pour les populations diploïdes et de 4.30 ± 1.51 pg à 5.27 ± 0.14 pg pour les populations de tétraploïdes. En outre, les grains de tétraploïdes germent significativement mieux que les graines des diploïdes. Les feuilles diffèrent considérablement entre les diploïdes (aciculaires et linéaires) et les tétraploïdes (lancéolées). Cette étude peut être considérée comme préliminaire pour une révision taxonomique de ce complexe d'espèces. D'autre part, grâce à l'ensemble des résultats obtenus, il est également possible de revisiter le concept d'unités évolutives significatives (ESUs) dans le complexe d'espèces A. grandiflora et donc de définir les groupes de populations devant faire l'objet de mesures distinctes. Ainsi, il est possible d'évaluer la pertinence de plans déjà entrepris et de proposer de nouveaux plans de restauration efficaces pour l'avenir de ce complexe d'espèces. / Population-level conservation is being extremely required to restrain the biodiversity loss within a species. So, the assessment of the variability within the species complex is being renowned as an important first step to well implement the future conservation settings for threatened species. The species complex of Arenaria grandiflora is a short-lived perennial herbaceous and a threatened taxon in certain of sites of its distribution areas in Europe, with unresolved gentics and taxonomy, which lead to potential problems in the conservation and utilization of the resource. A differenciation among populations of the species complex of A. grandiflora is presented in this study based on the genetic, cytogenetic and phenotypic patterns. Intraspecific ploidy level varaition is an important aspect of numerous species, so, the present study explores this phenomenon within the A. grandiflora species complex in some type of populations (27 natural populations). To infer the intraspecific genetic and cytogenetic patterns of variability among the studied natural populations of the investigated species complex (A. grandiflora), three methods were used : nuclear microsatellite markers, cytogenetic and flow cytometry approaches. Moreover, the phenotypic patterns of variation among both the stock of seeds and the herbarium materials of A. grandiflora were defined. These patterns were detected using three methods of seed germination (in vitro culture, filter papers and potting soil) and morphometric approaches. A significant differentiation among populations' patterns of molecular, cytogenetic and phenotypic variation was detected within the A. grandiflora species complex. Presence of two closely related cytotypes (diploids 2n=2x=22 and tetraploids 2n=4x=44) was detected using both classical and more recent methods (chromosome number count and flow cytometry respectively). The species complex of A. grandiflora exhibits high variation in 2C-DNA value, the genome size ranges from 2.11 ± 0.74 pg to 2.70 ± 0.11 pg for the diploid populations and from 4.30 ± 1.51 pg to 5.27 ± 0.14 pg for the tetraploid populations. Moreover, the seeds of tetraploids germinate well and in high proportion than the seeds of the diploid ones. In addition, both acicular and linear leaves from the diploid populations differ significantly within the diploids and with the lanceolate leaves of the tetraploid ones. New protocol of seed germination for the tetraploids by in vitro culture after scarifying was described for th first time. The affected factors on seed germination percentages were determinated by an explanatory model of six predictors (altitude, longitude, latitude, ploidy levls, both period and condition of seed storage). Consequently, all these findings are fundamental for the determination of the evolutionarily significant units (ESUs) within A. grandiflora species complex and thus the definition of efficient restoration plans in the future. This study would consider as the preliminary signal for necessary revision for the intraspecific taxonomic keys problematic for this species complex.

<p><em>Prospero&nbsp; autumnale&nbsp;</em> kompleks&nbsp; je&nbsp; taksonomski&nbsp; najintrigantniji&nbsp; član&nbsp; roda&nbsp; <em>Prospero,</em>&nbsp; sa&nbsp; centrom rasprostranjenja u Mediteranu. Kompleks se rasprostire i na obalama Atlantskog okeana u Francuskoj, sve do južnih&nbsp; delova Velike&nbsp; Britanije, zatim&nbsp; na Balkanskom poluostrvu, u Panonskoj&nbsp; niziji, sve&nbsp; do Krima, Kavkaza&nbsp; i&nbsp; delova&nbsp; Irana&nbsp; na&nbsp; istoku.&nbsp; Areal&nbsp; kompleksa&nbsp; se&nbsp; preklapa&nbsp; sa&nbsp; arealima&nbsp; ostale&nbsp; dve&nbsp; vrste&nbsp; roda&nbsp; &ndash;&nbsp; u<br />zapadnom Mediteranu sa <em>P. obtusifolium</em>, a u istočnim delovima Mediterana sa&nbsp;<em> P. hanburyi. </em>Za razliku od <em>P. obtusifolium&nbsp; i&nbsp; P. hanburyi,&nbsp; P. autumnale</em>&nbsp; kompleks se odlikuje visokom kariolo&scaron;kom varijabilno&scaron;ću.Razlikuju se četiri osnovna broja hromozoma&nbsp; x&nbsp; = 5, 6, 7 i četiri različita tipa genoma (A, B⁵, B ⁶ i B⁷ )&nbsp; i diploidna&nbsp; citotipa&nbsp; (AA,&nbsp; B ⁵B⁵,&nbsp; B ⁶B⁶i&nbsp; B ⁷B ⁷ )&nbsp; koja&nbsp; se&nbsp; razlikuju&nbsp; u&nbsp; odnosu&nbsp; na&nbsp; osnovni&nbsp; broj&nbsp; hromozoma, veličinu&nbsp; i&nbsp; morfologiju&nbsp; hromozoma.&nbsp; Genom&nbsp; B ⁵ ima&nbsp; x&nbsp; =&nbsp; 5,&nbsp; B⁶ x&nbsp; =&nbsp; 6,&nbsp; a&nbsp; genomi&nbsp; A&nbsp; i&nbsp; B⁷x&nbsp; =&nbsp; 7. Najrasprostranjeniji&nbsp; genom&nbsp; je&nbsp; B ⁷ ,&nbsp; koji&nbsp; je&nbsp; zabeležen&nbsp; u&nbsp; celom&nbsp; arealu&nbsp; kompleksa,&nbsp; dok&nbsp; je&nbsp; A&nbsp; zastupljen&nbsp; u zapadnom Mediteranu, B⁵ u Libiji, a B ⁶je endemičan za Krit. U okviru B ⁷ genoma se, dalje, razlikuju dve linije nastale kao posledica duplikacija 5S rDNK lokusa, pri čemu linija I ima jedan lokus, a kod linije II taj&nbsp; lokus&nbsp; je&nbsp; duplikovan.&nbsp; Osim&nbsp; diploidnih&nbsp; citotipova,&nbsp; poznato&nbsp; je&nbsp; i&nbsp; nekoliko&nbsp; ploidnih&nbsp; nivoa,&nbsp; od&nbsp; kojih&nbsp; su najučestaliji&nbsp; tetraploidi&nbsp; (2n=4x=28)&nbsp; i&nbsp; heksaploidi&nbsp; (2n=6x=42).&nbsp; Za&nbsp; <em>P.&nbsp; autumnale&nbsp;</em> kompleks&nbsp; je karakteristična varijabilnost u veličini genoma između različitih citotipova i unutar pojedinih citotipova. Genomsko restrukturiranje, koje je imalo najveću ulogu u evoluciji i diverzifikaciji kompleksa, nije imalo velikog uticaja na&nbsp; morfolo&scaron;ku varijabilnost, te je&nbsp; iz tog razloga kompleks&nbsp; morfolo&scaron;ki skoro uniforman. Ipak karakteri kao &scaron;to su: boja tunike lukovice, visina biljke, oblik i dimenzije lista, broj cvetova u cvasti i boja cvetova pokazuju izvesnu varijabilnost. Taksonomske nejasnoće nastaju zbog opisanih desetak vrsta između kojih ne postoje jasne morfolo&scaron;ke razlike i kod kojih je prisutno preklapanje vrednosti karaktera.Kako&nbsp; je&nbsp; do&nbsp; sada&nbsp; kompleks&nbsp; najvi&scaron;e&nbsp; bio&nbsp; predmet&nbsp; kariolo&scaron;kih&nbsp; istraživanja,&nbsp; pri&nbsp; čemu&nbsp; su&nbsp; izostale&nbsp; detaljne analize morfolo&scaron;ke i/ili anatomske varijabilnosti, uzorkovan je biljni materijal sa 37 lokaliteta na području Panonske nizije i Balkanskog poluostrva sa ciljem utvrđivanja morfolo&scaron;ke, anatomske, kao i kariolo&scaron;ke varijabilnosti. Određivan&nbsp; je broj hromozoma, nivoi ploidije&nbsp; i veličina genoma. Primenom univarijantne statističke&nbsp; metode,&nbsp; ispitana&nbsp; je&nbsp; varijabilnost&nbsp; morfolo&scaron;kih&nbsp; i&nbsp; anatomskih&nbsp; karaktera,&nbsp; a&nbsp; upotrebom multivarijantne&nbsp; statističke&nbsp; metode&nbsp; su&nbsp; testirane&nbsp; razlike&nbsp; između&nbsp; unapred&nbsp; definisanih&nbsp; grupa,&nbsp; koje&nbsp; su&nbsp; se odnosile na populacije i ploidne nivoe. Korespodentnom analizom su analizirani kvalitativni morfolo&scaron;ki i anatomski&nbsp; karakteri.&nbsp; Ukupno&nbsp; je&nbsp; analizirano&nbsp; 65&nbsp; karaktera&nbsp; (33&nbsp; morfolo&scaron;ka&nbsp; i&nbsp; 32&nbsp; ana tomska).&nbsp; Rezultati kariolo&scaron;ke&nbsp; analize&nbsp; se&nbsp; potvrdili&nbsp; varijabilnost&nbsp; kompleksa&nbsp; na&nbsp; istraživanom&nbsp; području.&nbsp; Detektovana&nbsp; su&nbsp; tri ploidna&nbsp; nivoa&nbsp; (diploidi,&nbsp; tetraploidi&nbsp; i&nbsp; heksaploidi),&nbsp; a&nbsp; potvrđena&nbsp; je&nbsp; i&nbsp; varijabilnost&nbsp; u&nbsp; veličini&nbsp; genoma. Poređenjem monoploidne veličine genoma između tri ploidna nivoa je detektovano smanjivanje veličine genoma&nbsp; sa&nbsp; povećanjem&nbsp; nivoa&nbsp; ploidije.&nbsp; U&nbsp; odnosu&nbsp; na&nbsp; koeficijent&nbsp; varijabilnosti,&nbsp; konstatovano&nbsp; je&nbsp; da&nbsp; se većina&nbsp; morfolo&scaron;kih&nbsp; karaktera&nbsp; nalazi&nbsp; u&nbsp; zoni&nbsp; umerene&nbsp; varijabilnosti&nbsp; (22),&nbsp; a&nbsp; samo&nbsp; pet&nbsp; karaktera&nbsp; je visokovarijabilno.&nbsp; Anatomski&nbsp; karakteri&nbsp; su&nbsp; raspoređeni&nbsp; u&nbsp; četiri&nbsp; kategorije&nbsp; (niskovarijabilni, umerenovarijabilni, visokovarijabilni i veoma visokovarijabilni), pri čemu većina karaktera (20) pripada umerenovarijabilnoj&nbsp; kategoriji. Četiri&nbsp; kvalitativna&nbsp; morfolo&scaron;ka (oblik lukovice, boja tunike, boja cveta i oblik&nbsp; plodnika)&nbsp; i&nbsp; sedam&nbsp; kvalitativnih&nbsp; anatomskih&nbsp; karaktera&nbsp; (oblik&nbsp; poprečnog&nbsp; preseka&nbsp; lista,&nbsp; oblik&nbsp; ćelija epidermisa na licu i&nbsp; naličju,&nbsp; oblik ćelija palisadnog tkiva na licu&nbsp; i&nbsp; naličju, prisustvo papila&nbsp; i&nbsp; kristala u ćelijama&nbsp; parenhima)&nbsp; su&nbsp; pokazala&nbsp; varijabilnost.&nbsp; U&nbsp; korespodentnoj&nbsp; analizi,&nbsp; zasnovanoj&nbsp; na&nbsp; kvalitativnim morfolo&scaron;kim&nbsp; karakterima,&nbsp; izdvojile&nbsp; su&nbsp; se&nbsp; tri&nbsp; grupe.&nbsp; Za&nbsp; prvu&nbsp; grupu&nbsp; su&nbsp; bili&nbsp; zajedničke&nbsp; &scaron;irokojajaste&nbsp; i uzanojajaste&nbsp; lukovice&nbsp; sa&nbsp; ružičastom&nbsp; tunikom,&nbsp; jedinkama&nbsp; u&nbsp; drugoj&nbsp; grupi&nbsp; su&nbsp; bili&nbsp; svojstveni&nbsp; jajasti&nbsp; i uzanojajasti plodnici i lukovice sa braon tunikom, dok su za treću grupu bili karakteristični &scaron;irokojajasti plodnici, loptaste i pljosnate lukovice. U odnosu na kvalitativne anatomske karaktere najvi&scaron; e se izdvojila jedna&nbsp; grupa&nbsp; za&nbsp; koju&nbsp; su&nbsp; bile&nbsp; karakteristične&nbsp; gusto&nbsp; raspoređene&nbsp; papile&nbsp; i&nbsp; prisustvo&nbsp; četvorougaonih&nbsp; i okruglastih epidermalnih ćelija na abaksijalnoj strani lista. Rezultati multivarijantnih analiza, zasnovanih na&nbsp; populacijama&nbsp; kao&nbsp; unapred&nbsp; definisanim&nbsp; grupama&nbsp; i&nbsp; kvantitivnim&nbsp; karakterima,&nbsp; ukazali&nbsp; su&nbsp; na&nbsp; složenu varijabilnost&nbsp; uzorka&nbsp; i&nbsp; izostanak&nbsp; jasne&nbsp; separacije&nbsp; grupa.&nbsp; Naznake&nbsp; razdvajanja&nbsp; grupa&nbsp; su&nbsp; bile&nbsp; uočljive&nbsp; u analizi&nbsp; morfo-anatomske&nbsp; matrice.&nbsp; Izdvojili&nbsp; su&nbsp; se&nbsp; sledeći&nbsp; karakteri:&nbsp; visina&nbsp; stabla,&nbsp; dužina&nbsp; cvasti,&nbsp; broj cvetova,&nbsp; povr&scaron;ina&nbsp; poprečnog&nbsp; preseka&nbsp; lista,&nbsp; ukupna&nbsp; povr&scaron;ina&nbsp; palisadnog&nbsp; tkiva&nbsp; i&nbsp; ukupna&nbsp; povr&scaron;ina sunđerastog tkiva. Najjasnija razdvajanja su uočena u analizama gde su ploidni nivoi predstavljali&nbsp; a priori definisane&nbsp; grupe,&nbsp; naročito&nbsp; u&nbsp; kombinaciji&nbsp; morfolo&scaron;kih&nbsp; i&nbsp; anatomskih&nbsp; karaktera.&nbsp; Karakteri&nbsp; sa diskriminacionim&nbsp; potencijalom&nbsp; između&nbsp; jedinki&nbsp; koje&nbsp; pripadaju&nbsp; različitim&nbsp; ploidnim&nbsp; nivoima&nbsp; jesu:&nbsp; broj<br />cvetova,&nbsp; &scaron;irina&nbsp; listića&nbsp; perigona&nbsp; unutra&scaron;njeg&nbsp; kruga&nbsp; i&nbsp; filamenta&nbsp; spolja&scaron;njeg&nbsp; kruga,&nbsp; povr&scaron;ina&nbsp; poprečnog preseka&nbsp; lista,&nbsp; ukupna&nbsp; povr&scaron;ina&nbsp; palisadnog&nbsp; tkiva,&nbsp; povr&scaron;ina&nbsp; ćelija&nbsp; palisadnog&nbsp; tkiva,&nbsp; visina&nbsp; i&nbsp; &scaron;irina&nbsp; ćelija palisadnog tkiva i udeo epidermisa. Od sva tri ploidna nivoa, najvi&scaron;e izdvojene su bile diploidne jedinke, koje&nbsp; se&nbsp; od&nbsp; tetraploida&nbsp; i&nbsp; heksaploida&nbsp; mogu&nbsp; razlikovati&nbsp; na&nbsp; osnovu:&nbsp; dužina&nbsp; filamenata&nbsp; spolja&scaron;njeg&nbsp; i unutra&scaron;njeg&nbsp; kruga&nbsp; cveta,&nbsp; povr&scaron;ine&nbsp; ćelija&nbsp; palisadnog&nbsp; tkiva,&nbsp; visine&nbsp; i&nbsp; &scaron;irine&nbsp; ćelija&nbsp; palisadnog&nbsp; tkiva,&nbsp; kao&nbsp; i ukupne&nbsp; povr&scaron;ine&nbsp; palisadnog&nbsp; tkiva.&nbsp; Tetraploidi&nbsp; i&nbsp; heksaplodi&nbsp; se&nbsp; najvi&scaron;e&nbsp; međusobno&nbsp; razlikuju&nbsp; na&nbsp; osnovu karaktera u regionu cveta: prečnik otvorenog perigona, dužine listića perigona spolja&scaron;njeg kruga cveta i &scaron;irine filamenta spolja&scaron;njeg&nbsp; kruga cveta.&nbsp; Uočene razlike&nbsp; između tri analizirana ploidna&nbsp; nivoa (diploidi, tetraploidi&nbsp; i&nbsp; heksaploidi),&nbsp; u&nbsp; taksonomskom&nbsp; smislu&nbsp; se&nbsp; mogu&nbsp; tumačiti&nbsp; pre&nbsp; kao&nbsp; jedna&nbsp; od&nbsp; infraspecijskih kategorija, a ne kao kategorija koja bi odgovarala vrsti.</p> / <p>Prospero autumnale&nbsp; complex is the most taxonomically intricate member of the genus&nbsp; Prospero&nbsp; with the centre of distribution on the Mediterranean Basin, westwards to&nbsp; the Atlantic coast in France as far north&nbsp; as&nbsp; Great&nbsp; Britain,&nbsp; northwards&nbsp; to&nbsp; the&nbsp; Pannonian&nbsp; Basin&nbsp; and&nbsp; Crimea,&nbsp; and&nbsp; eastwards&nbsp; to&nbsp; Iran.&nbsp; The distribution area of the complex overlaps with distribution areas of the other two species of the genus<br />Prospero-P.&nbsp; obtusifolium&nbsp; is&nbsp; present&nbsp; in&nbsp; the&nbsp; western&nbsp; parts&nbsp; of&nbsp; the&nbsp; Mediterranean,&nbsp; while&nbsp; P.&nbsp; hanburyi&nbsp; is distributed in the eastern Mediterranean. Unlike&nbsp; P. obtusifolium and P. hanburyi, P. autumnale complexis characterized by extraordinary karyological&nbsp; cariation. It encompasses&nbsp;&nbsp; four distinct genomes (A, B&nbsp; 5 , B 6 , B 7 ) and four distinct diploid cytotypes (AA, B 5 B 5 , B 6 B 6 , B 7 B 7 ), each with a unique combination of<br />basic chromosome&nbsp; number (x&nbsp; = 5, 6, 7).&nbsp; An additional difference is related to&nbsp; chromosome&nbsp; size and morphology. The B 5 genome&nbsp; has&nbsp; x&nbsp; = 5, B 6 x&nbsp; = 6, and A and B 7x&nbsp; = 7 basic chromosome numbers. The B 7 genome&nbsp; is&nbsp; present&nbsp; in&nbsp; the&nbsp; whole&nbsp; distribution&nbsp; area&nbsp; of&nbsp; P.&nbsp; autumnale&nbsp; complex,&nbsp; while&nbsp; genome&nbsp; A&nbsp; is distributed in the western Mediterranean, B 5 is restricted to Libya, and B 6 is endemic to&nbsp; Crete. Within diploids and tetraploids&nbsp; of&nbsp; B 7 genome, two&nbsp; lineages&nbsp; occur as a consequence&nbsp; of&nbsp; duplication&nbsp; of the 5S rDNA locus. Type I (lineage) has a single locus, while in type II (lineage) 5S rDNA locus is duplicated. Besides diploid cytotypes, the polyploids cytotypes are also known. The most common polyploids are tetra- (2n=4x=28) and hexaploids (2n=6x=42). Variability in the genome size within, as well as between cytotypes, is also characterized for the complex. Genomic restructuring, which played the b iggest role in evolution&nbsp; and&nbsp; diversification&nbsp; of&nbsp; the&nbsp; P.&nbsp; autumnale&nbsp; complex,&nbsp; did&nbsp; not&nbsp; have&nbsp; a&nbsp; major&nbsp; impact&nbsp; on morphological&nbsp; variability.&nbsp; Only&nbsp; slight&nbsp; variation&nbsp; has&nbsp; been&nbsp; detected&nbsp; in&nbsp; plant,&nbsp; tepal&nbsp; and&nbsp; filament&nbsp; size, flower&nbsp; and&nbsp; seed&nbsp; color,&nbsp; shape&nbsp; and&nbsp; size&nbsp; of&nbsp; leaves&nbsp; a nd&nbsp; color&nbsp; of&nbsp; bulbs.&nbsp; Taxonomic&nbsp; ambiguities&nbsp; are<br />additionally&nbsp; caused&nbsp; by&nbsp; description&nbsp; of&nbsp; the&nbsp; new&nbsp; ten&nbsp; species&nbsp; of&nbsp; the&nbsp; complex.&nbsp;&nbsp; morphological&nbsp; differences between those species are unclear, with overlapping values of the most morphological traits. Until now, P. autumnale&nbsp; complex was mostly karyologicaly investigated, without detail analyses of morphological and/or&nbsp;&nbsp; anatomical&nbsp; variability.&nbsp; The&nbsp; aim&nbsp; of&nbsp; the&nbsp; present&nbsp; study&nbsp; was&nbsp; to&nbsp; investigate&nbsp; karyological, morphological and anatomical variability on individuals collected on 37 localities across the Pannonian Basin and&nbsp; Balkan Peninsula. Basic chromosome&nbsp; number, ploidy&nbsp; levels, as well as&nbsp; genome size&nbsp; were determined. The variability of morphological and anatomical characters was examined using univariate statistical&nbsp; methods.&nbsp; Differences&nbsp; between&nbsp; predefined&nbsp; groups&nbsp; (populations&nbsp; and&nbsp; ploidy&nbsp;&nbsp; levels)&nbsp; were investigated&nbsp; using&nbsp; multivariate&nbsp; statistics&nbsp; with&nbsp; the&nbsp; attempts&nbsp; to&nbsp; identify&nbsp; morphological&nbsp; and&nbsp; anatomical characters&nbsp; with&nbsp; discriminatory&nbsp; potential.&nbsp; For&nbsp; analysing&nbsp; qualitative&nbsp; morphological&nbsp; and&nbsp; anatomical characters, correspondence analysis was conducted. In total 65 traits were analyzed (33&nbsp; morphological and&nbsp; 32&nbsp; anatomical).&nbsp; The&nbsp; results&nbsp; of&nbsp; karyological&nbsp; analysis&nbsp; confirmed&nbsp; the&nbsp; high&nbsp; variation&nbsp; of&nbsp; the&nbsp; P. autumnale&nbsp; complex&nbsp; in the study area. Three&nbsp; ploidy&nbsp; levels (diploids, tetraploids and&nbsp; hexaploids)&nbsp; were detected,&nbsp; and&nbsp; the&nbsp; genome&nbsp; size&nbsp; variation&nbsp; was&nbsp; confirmed.&nbsp; Genome&nbsp; downsizing&nbsp; was&nbsp; observed&nbsp; by comparing&nbsp; monoploid&nbsp; genome&nbsp; sizes&nbsp; between&nbsp; three&nbsp; ploidy&nbsp; levels.&nbsp; According&nbsp; to&nbsp; the&nbsp; oefficient&nbsp; ofc variation,&nbsp; most&nbsp; morphological characters show&nbsp; moderate&nbsp; variation (22). Only&nbsp; five traits showed&nbsp; high variation.&nbsp; Anatomical&nbsp; characters&nbsp; were&nbsp; classified&nbsp; into&nbsp; four&nbsp; categories&nbsp; according&nbsp; to&nbsp; the&nbsp; coefficient&nbsp; of variation (with low, moderate, high and very high variation), but the&nbsp; most traits (20) showed moderate<br />variation. Variation in qualitative morphological (bulb shape and color, flower color and ovary shape) and seven&nbsp; qualitative anatomical characters (leaf cross-sectional area shape, shape&nbsp; of the adaxial and abaxial&nbsp; epidermal&nbsp; cells,&nbsp; shape&nbsp; of&nbsp; the&nbsp; adaxial&nbsp; and&nbsp; abaxial&nbsp; palisade&nbsp; cells,&nbsp; presence&nbsp; of&nbsp; the&nbsp; papillae&nbsp; and crystals&nbsp; in&nbsp; the&nbsp; parenchyma&nbsp; cells)&nbsp; were&nbsp; recorded.&nbsp; Three&nbsp; groups&nbsp; of&nbsp; populations,&nbsp; as&nbsp; a&nbsp; result&nbsp; of&nbsp; the correspondence&nbsp; analysis,&nbsp; based&nbsp; on&nbsp; qualitative&nbsp; morphological&nbsp; characters,&nbsp; were&nbsp; formed.&nbsp; Populations&nbsp; of the first group showed common characteristics such as broadly and narrowly ovate shaped bulbs with pink&nbsp; outer&nbsp; tunic.&nbsp; The&nbsp; second&nbsp; group&nbsp; was&nbsp; characterized&nbsp; by&nbsp; bulbs&nbsp; with&nbsp; brown&nbsp; outer&nbsp; tunic,&nbsp; ovate&nbsp; and narrowly ovate ovary, while the third group had broadly ovate ovaries, globose and flattened bulbs. In relation&nbsp; to&nbsp; qualitative&nbsp; anatomical&nbsp; characters,&nbsp; only&nbsp; one&nbsp; group&nbsp; was&nbsp; the&nbsp; most&nbsp; distinguished&nbsp; and&nbsp; was characterized by densely distributed papillae, squared and rounded shape of abaxial epidermal cells. The results&nbsp; of&nbsp; multivariate&nbsp; analyses&nbsp; of&nbsp; quantitative&nbsp; traits,&nbsp; based&nbsp; on&nbsp; populations&nbsp; as&nbsp; presumptive&nbsp; groups, revealed&nbsp; similar&nbsp; patterns&nbsp; without&nbsp; structuring&nbsp; and&nbsp; with&nbsp; no&nbsp; specific&nbsp; groupings.&nbsp; The&nbsp; tendency&nbsp; toward&nbsp; a separation&nbsp; of&nbsp; the&nbsp; populations&nbsp; was&nbsp; noticeable&nbsp; in&nbsp; the&nbsp; analysis&nbsp; based&nbsp; on&nbsp; combined&nbsp; morpho-anatomical characters. The highest correlation with the canonical axes showed: stem height, inflorescence length,number of flowers, leaf cross-sectional area, palisade and spongy tissue area. The clearest separationsbetween groups were observed with ploidy levels as presumptive groups. Morpho-anatomical traits with discriminatory potential among ploidy levels were: number of flowers, inner tepal width, outer filament width, leaf cross-sectional area, palisade tissue area, the cross-sectional area of palisade cells, height and width&nbsp; of palisade cells and&nbsp; epidermis percentage. The&nbsp; most&nbsp; distinct&nbsp; group among three ploidy&nbsp; levels were diploids and could be distinguished from tetra-&nbsp; and hexaploids by outer and inner&nbsp; filament width, the&nbsp; cross-sectional area&nbsp; of palisade cells, the&nbsp; width of palisade cells, the&nbsp; height&nbsp; of palisade cells and palisade tissue area. Tetra-&nbsp; and&nbsp; hexaploids&nbsp; differed&nbsp; mostly&nbsp; in floral characters: open flower diameter, outer tepal length and outer filament width. For taxonomic purposes, the level of overlap indicates that the ploidy levels could be regarded as showing intraspecific variation.</p>

Les habitats sur le substrat de serpentine représentent un environnement hostile pour le développement des plantes. Ils sont caractérisés par un faible nombre d’espèces mais un haut niveau d’endémisme. Cette étude présente pour la première fois une série des données sur la taille du génome, du nombre chromosomique, du niveau de ploïdie, de l’affinité pour le substrat, du cycle de vie, du type et de la forme de croissance des serpentinophytes dans l’extrême nord-ouest de la zone de serpentine dans les Balkans. Les 308 taxons des plantes étudiées comprennent appartenant à 213 genres, dont la taille du génome est donnée pour la première fois pour 28 genres et 99 espèces. En utilisant les critères de Leitch, plus de la moitié des taxons (55.63%) appartiennent au groupe des très petits génomes, 22.19% aux petits, 18.75% aux moyens, 3.13% aux grands, et seulement 0.31% aux très grands génomes. Concernant l'affinité au substrat, la majorité d’espèces (171) sont indifférentes ou des serpentinophytes facultatives (103). Selon le type de cycle de vie, ~ 4% des espèces sont annuelles, 88.31% pérennes, dont 57% possèdent de très petits génomes. Les hémicryptophytes représentent une forme de vie dominante (48.38%), tandis que les phanérophytes représentent 17%, les chaméphytes 15%, les thérophyte 9% et les géophytes 9%. Il est évident que le stress hydrique, les températures élevées et la présence de métaux lourds dans les habitats sur la serpentine jouent une haute pression sélective et favorisent des espèces pérennes à très petits génomes.Le Narcissus poeticus (Amaryllidaceae), serpentinophyte facultative, est l’ancêtre des narcisses cultivés. C'est la première étude de N. poeticus et de sa rhizosphère dans les populations naturelles. Il montre une tolérance au pH du sol qui varie du 4.64 à 7.85. Les concentrations totales de nickel, de cobalt et de magnésium sont plus élevées dans les sols sur serpentine que dans ceux sur calcaires. Narcissus poeticus est caractérisé par une plus grande accumulation de manganèse, de nickel et de magnésium dans ses parties aériennes. Le cobalt, par contre, a une concentration totale uniforme dans toutes les parties de la plante. Une autre caractéristique inhabituelle de N. poeticus est son plus grand rapport molaire Ca/Mg dans les parties souterraines, probablement dû à sa forme de vie (géophytes) et une dormance estivale. Il est évident que, même si N. poeticus accumule certaines quantités de métaux lourds estimés (Mn, Ni, Co, Fe), il n'est pas pour autant un hyperaccumulateur.Une partie importante de ce travail concerne la variabilité de la structure chromosomique, la taille du génome, le niveau de ploïdie et la présence de chromosomes B dans 13 populations naturelles de N. poeticus poussant sur différents substrats géologiques et dans différentes conditions environnementales. La technique de la cytométrie en flux a été utilisée pour estimer la taille du génome, l’hybridation in situ fluorescente (FISH) pour la cartographie physique de l'ADNr, le fluorochrome banding pour l'organisation de l’hétérochromatine et la coloration au nitrate d’argent pour estimer l'activité des gènes ribosomiques. L’organisation des gènes ribosomiques et l’existence des triploïdes naturels ont été rapportés ici pour la première fois. Présence des individus portant de chromosomes B (dans 9 populations sur 13) et de translocations chromosomiques a été détectée. Un système particulier de chromosomes B présente trois différents morphotypes. Le submétacentrique type, le plus fréquent, possède quatre paternes différents dans l’organisation de l’hétérochromatine et de l'ADNr. La coloration à l’AgNO3 a montré que le nombre de nucléoles formés augmente en présence des chromosomes B portant des gènes ribosomiques, dont l’activité est ainsi prouvée. Les résultats obtenus démontrent que N. poeticus possède un génome dynamique avec la quantité d’ADN variable en raison de la présence de polyploïdie, de chromosomes B et de réarrangements chromosomiques. Il semble que les modifications observées reflètent la réponse du génome à différentes conditions environnementales où les individus portant les chromosomes B pourraient avoir des avantages sélectifs. / Habitats on serpentine substrate present a hostile environment for the plants development. They are characterized by a small number of species, but high levels of endemism. This study shows for the first time a series of data on genome size, chromosome number, ploidy level, the affinity to the substrate, the life cycle, the type and form of growth in the extreme northwest region of serpentine area in the Balkans. The sample includes 308 taxa belonging to 213 genera, with new values recorded for 28 genera and 99 species. Using Leitch’s criteria, more than half of estimated taxa (55.63%) belong to the group of very small genomes, 22.19% small, 18.75% intermediary, 3.13% large and only 0.31% to very large genomes. Regarding the affinity to the substrate, the majority of species (171) were indifferent or facultative serpentinophytes (103). Concerning the life cycle, ~ 4% of species are annuals and 88.31% perennials, and 57% had very small genomes. Hemicryptophytes represent a dominant life form (48.38%), phanerophytes 17%, 1chamaephytes5%, therophytes 9% and geophytes 9%. It is clear that the water stress, high temperatures and presence of heavy metals in serpentine habitats have the high selective pressure and favor perennial species with very small genome.The Narcissus poeticus (Amaryllidaceae), facultative serpentinophyte, is the ancestor of cultivated daffodils. This is the first study of N. poeticus and its rhizosphere in natural populations. It shows tolerance to soil pH ranging from 4.64 to 7.85. Serpentine soils have total concentrations of nickel, cobalt and magnesium highest, compared with calcareous soils. Narcissus poeticus is characterized by the greater accumulation of manganese, nickel and magnesium in the aerial parts of plant. Against the cobalt has a uniform total concentration in all parts of the plant. Another unusual feature of N. poeticus is the highest molar ratio Ca / Mg in the underground parts, probably du to his life form (geophytes) and summer dormancy. It is obvious that although N. poeticus accumulate certain amounts of estimated heavy metals (Mn, Ni, Co, Fe), it does not a hyperaccumulator.An important part of this work concerns the variability of the chromosome structure, genome size, the ploidy level and the presence of B chromosomes in 13 natural populations growing on different soils and under different environmental conditions. The technique of flow cytometry was used to estimate the genome size, fluorescent in situ hybridization (FISH) for the physical mapping of rDNA, the fluorochrome banding for the organization of heterochromatin and silver staining to estimate the activity of ribosomal genes. Organization of ribosomal genes and natural triploids have been reported here for the first time. Presence of individuals carrying B chromosomes (in 9 / 13 populations) and chromosomal translocations were detected. A particular system of B chromosomes presents three different morphotypes. The most common submetacentric type shows four different patterns in the organization of heterochromatin and rDNA. The AgNO3 staining showed that the number of nucleoli formed increases in the presence of B chromosomes carrying ribosomal genes, which proved their activity. The obtained results show that N. poeticus has a dynamic genome with the variable amount of DNA due to the presence of polyploidy, B chromosomes and chromosomal rearrangements. It seems that the observed changes reflect the response of the genome to different environmental conditions in which individuals carrying B chromosomes may have some selective advantages / Habitati na serpentinskim substratima predstavljaju nepovoljne uvjete za razvoj biljaka. Karakteriziraju se sa malim brojem vrsta, ali prisustvom velikog broja endema. U ovoj studiji se po prvi put prezentira serija podataka o veličini genoma serpentinofita, njihovom hromosomskom broju, nivou ploidije, sklonosti ka supstratu, tipu životnog ciklusa i životne forme na krajnjem sjeverozapadnom dijelu serpentinskog područja Balkanskog poluostrva. Uzorak je obuhvatao 308 svojti iz 213 rodova, sa novim vrijednostima za 28 rodova i 99 vrsta. Prema Leitch-evim kriterijima, više od polovine analiziranih svojti (55.63%) pripadale su grupi vrlo malih genoma, 22.19% malim, 18.75% srednjim, 3.13% velikim i samo 0.31% vrlo velikim genomima. U odnosu na sklonost ka supstratu, glavnina vrsta (171) su bile indiferentne ili fakultativne serpentinofite (103). U zavisnosti od životnog ciklusa, ~ 4% vrsta su bile jednogodišnje, a 88.31% višegodišnje, od kojih je 57% imalo vrlo male genome. Hemikriptofite su predstavljale dominantnu životnu formu (48.38%), koju slijede fanerofite (17%), hamefite (15%), terofite (9%) i geofite (9%). Iz dobivenih rezultata proizilazi da vodni stres, visoke temperature i prisustvo teških metala u serpentinskim habitatima imaju visok selektivni pritisak i favoriziraju višegodišnje vrste sa vrlo malim genomom.Narcissus poeticus (Amaryllidaceae), fakultativna serpentinofita, je predak kultiviranih narcisa. Ovo je prva studija o N. poeticus i njegovoj rizosferi u prirodnim populacijama. Ova vrsta pokazuje toleranciju na promjene pH vrijednosti u dijapazonu od 4.64 do 7.85. Totalne koncentracije nikla, kobalta i magnezija u serpenitnskim tlima su bile veće nego u krečnjačkim. Narcissus poeticus se karakterizirao većom akumulacijom mangana, nikla i magnezija u nadzemnim dijelovima biljke. Suprotno, kobalt je imao skoro istu totalnu koncentraciju u svim dijelovima biljke. Druga neuobičajena karakteristika N. poeticus je najveći iskazani molarni odnos Ca/Mg u podzemnim dijelovima, vjerovatno zbog njegove životne forme (geofita) i ljetne dormancije. Očito je da iako N. poeticus akumulira određene količine istraživanih teških metala (Mn, Ni, Co, Fe) on se ne moze smatrati nije njihovim hiperakumulatorom.Važan dio ove studije se odnosi na varijabilnost hromosomske strukture, veličine genoma, nivoa ploidije i prisustva B-hromosoma u 13 prirodnih populacija N. poeticus koje rastu na različitim geološkim supstratima i pod različitim okolišnim uslovima. Korištena je tehnika protočne citometrije za određivanje veličine genoma, fluorescentna in situ hibridizacija (FISH) za fizicko mapiranje rDNK, fluorohrom banding za organizaciju heterohromatina i bojenje srebrenim nitratom za utvrđivanje aktivnosti ribozomalnih gena. Organizacija ribosomalnih gena i prisustvo prirodnih triploida su u ovoj studiji saopćeni po prvi put. Uočeno je prisustvo individua koje nose B-hromosome (u 9 od 13 populacija) i hromosomske translokacije. Poseban sistem B-hromosoma je predstavljen sa tri različita morfotipa. Najčešći submetacentrični tip pokazuje četiri različita obrasca u organizaciji heterohromatina i rDNK. Bojenje s AgNO3 je pokazalo da se formirani broj nukleolusa povećava u prisustvu B-hromosoma koji nose ribosomalne gene, što potvrđuje njihovu aktivnost. Dobiveni rezultati pokazuju da N. poeticus ima dinamičan genom sa različitom količinom DNK usljed prisustva poliploidije, B-hromosoma i hromosomskih rearanžmana. Uočene promjene najvjerovatnije odražavaju odgovor genoma na različite okolišne uslove u kojima individue koje posjeduju B-hromosome imaju izvjesnu selektivnu prednost.

7 Abstract The genus Geosmithia Pitt (Ascomycota: Hypocreales) belongs to fungi living in symbioses with bark beetles. Its original strategy is association with phloeophagous bark beetles (Coleoptera: Scolytinae). The Geosmithia shows strong affiliation to vector (bark beetles) worldwide and the spectrum of host plants is delimitated by niche of vector. The genus includes the specialists to family Pinaceae, but also the generalists with wide range of host plants mainly belonging to broad-leaved trees. G. morbida changed its ecology from saprotrophic to pathogenic way of life and causes decline of Junglans nigra in the USA. Characteristics which allow its pathogenesis are not known. Another derived strategy, which occurred at least twice independently, is association with the ambrosia beetles. The ambrosia beetles create galleries in xylem with low nutritive value, and thus they cultivate ambrosia fungus, on which they are entirely nutritively dependent. The ambrosia fungi share convergent phenotype which leads to large terminal conidia and to ability of yeast growth. This master thesis is focusing on study of the features, which are important for individual ecological groups: the specialists to family Pinaceae, the pathogene, the ambrosia fungi and the generalists. It is becoming apparent that the most...

Presented thesis evaluates the risk of ongoing hybridization (antropohybridization) in highly endangered Prunus fruticosa in the Czech Republic and selected adjacent countries. Absolute genome size analysis (estimated by flow cytometry) combined with both numeric and geometric morphometrics were used for evaluation of hybridization. Prunus fruticosa frequently hybridize with naturalized Prunus cerasus (emerging tetraploid hybrid Prunus ×eminens) and native Prunus avium (forming triploid hybrid Prunus ×mohacsyana). Discrimination between P. ×eminens and P. ×mohacsyana is difficult, when using leaf morphology characters only, so the occurrence of triploid hybrids was strongly underestimated in the Czech Republic (only tetraploid hybrids were reported). Both hybrids are surely differentiated using flow cytometry analysis (based on different ploidy level). The majority of analyzed populations is formed by either individuals of pure P. fruticosa or one of the mentioned hybrids. Only four populations were mixed. Continuous variability in absolute genome size was found in two of them, which may indicate hybrid swarm forming (incl. primary hybrids and backcrosses). Our findings can be considered only as indirect evidence for introgression, which needs to be confirmed by molecular markers (for example...

Bryophilous Pezizales represent a species-rich group of fungi closely associated with bryophytes. Their ascospore morphology is highly variable and they strongly differ also in the genome size and ecology. They could thus represent an interesting model system for the research of evolution of ascospore morphology and their dispersal. The aims of my thesis were to test whether their genome size, number of nuclei in ascospores and ecology of host bryophyte influence their ascospore morphology and to experimentally test the effect of ascospore morphology on their active dispersal. I studied 52 species of bryophilous Pezizales. I reconstructed their phylogeny based on the sequences of three DNA regions, which I then used for the testing of relationships between individual variables using the phylogenetic generalized least squares. For the majority of species, I obtained measurements from morphometric analysis, genome size measurements using flow cytometry, and determined the number of nuclei in their ascospores using the fluorescent microscopy. I localised the infection apparatus and included also the ecological characteristics of the host bryophytes into the analyses. Using the experiments with horizontal ascospore discharge, I measured the distance of active ascospore ejection and recorded whether...

Nuclear DNA content (genome size) is one of the basic characteristics of living organisms. In the Angiosperms, the range of genome size is 2,300-fold, which raises questions about the causes and consequences of this tremendous variation. This thesis deals with genome size in plants from the level of intraspecific homoploid variation, through intraspecific ploidy variation, to interspecies comparisons. On various study systems we investigated the dynamics and ranges of genome size variation, tried to reveal possible associations between genome size and selected biological traits, and assessed the extent to which differences in genome size are manifested at the ecological and evolutionary level. As a means of estimating genome size we applied flow cytometry (FCM). In Taraxacum stenocephalum we conducted a detailed study of its enormous genome size variation. We carried out crossings of parents with various genome sizes and compared these parental genome sizes with those of F1 offspring. We also attempted to reveal the association of genome size with various growth traits. In Galium valdepilosum and Arabidopsis arenosa we carried out an extensive flow-cytometric ploidy level screening and compared the distribution and ecological preferences of detected cytotypes. We studied the Andean genus...