The evolution of plant genomes is notable for manifesting a cycle of whole genome doubling, fractionation (gradual loss of redundant genes) and speciation. The thesis is based on a branching process model of the doubling and fractionation process, integrated with a standard model of sequence divergence. The immediate application of this work is to account for the distribution of sequence similarity for duplicate gene pairs, both within plant genomes and between two related plant genomes in terms of a cycle of polyploidization, fractionation and speciation. We derive a mixture distribution for duplicate gene pair similarities generated by speciation and/or repeated episodes of polyploidization. We account not only for the timing of these events in terms of local modes or peaks of the component distributions, but also their volume, or amplitude, and variance. We outline how to infer the parameters of the model. We illustrate with analyses of the distribution of homolog similarities in a number of plant families: Brassicaceae, Solanaceae and Malvaceae. To our knowledge, this is the first method to account for the volume of the component normals of a distribution of similarities, preliminary to an evolutionarily meaningful inference procedure. In addition, we solve the problem of identifying the ploidy level of a series of two or three polyploidizations by invoking the observed and predicted gene triple profiles for each model, i.e., by calculating the probability of the four types of triple with origins in one or the other event, or both.

Although genomes are perhaps the single most important element of living systems, why they feature such striking variation and how this variation is maintained within and across natural populations remains unclear. One of the most common and important means by which genomic variation is generated is ploidy elevation. While polyploidy has been implicated in the remarkably successful radiations of angiosperms, teleost fish, and amphibians, the phenotypic consequences of changes in ploidy level are poorly understood, especially in animals. I use a large, multi-year common garden experiment to identify potential life history costs and benefits of polyploidy and asexual reproduction, a trait often associated with polyploidy, in Potamopyrgus antipodarum. This snail is well suited for studying ploidy variation and sex because diploid sexuals and triploid and tetraploid asexuals frequently coexist, allowing us to use comparisons of sexuals to asexuals and triploid to tetraploid asexuals to study both the effects of ploidy elevation and sex. I detected a strong negative correlation between growth rate and time to maturity and found that sexual P. antipodarum grew and matured significantly more slowly than the polyploid asexuals. Sexual P. antipodarum were also more likely to die before achieving reproductive maturity than their asexual counterparts. By contrast, there were no apparent life history differences between triploid and tetraploid asexuals, indicating that direct phenotypic benefits of ploidy elevation are unlikely to explain the relatively rapid growth and maturation of asexuals. My results suggest that ploidy elevation does not inevitably confer phenotypic consequences, that reproductive mode influences life history trait expression, and that sexual P. antipodarum persist in many natural populations in spite of substantial life history disadvantages.

Peculiarities of edible onions (Allium cepa L.) gynogenesis investigated in the dissertation work. Conditions for creation of dihaploid plants evaluated. Biological assumptions for preparation of methodical suggestions, that would enable improving of gynogenesis, determined. Stimulation effect of using TDZ and NAR in media on the formation of edible onion embryogenic tissue has been revealed for the first time. Characteristic higher frequency of gynogenesis of unfertilized flower of edible onion isolated from the flower stems soaked in 2,4-D solution has been evaluated. By using experimental method it has been established that 3 day length gynogenesis induction period, using media containing 2,4-D and BA, is enough to induce gynogenesis of edible onion. High heterogeneity of edible onion variety population ‘Lietuvos didieji’ has been demonstrated from the point of organogenesis in isolated unfertilized flower culture. It has been established that the efficiency of edible onion gynogenesis can be increased by decreasing plant donor growing temperature in the final phases of flower development and using of exogenous growth regulators TDZ and NAA in plant regeneration media as well as by flower stems soaking in 2,4-D solution for 14 days. Plants with characteristic high gynogenesis frequency have been determined according to evaluation of edible onion variety population ‘Lietuvos didieji’ organogenetic response. 10 homozygous lines of edible onion have been created. 2 lines with... [to full text]

The Master's thesis studied the Odontites vernus group in the Czech Republic. The group was presented by two different taxa based on the seasonal types and the ploidy levels: an early flowering tetraploid Odontites vernus subsp. vernus (2n = 4x = 40) and a late-flowering diploid Odontites vernus subsp. serotinus (2n = 2x = 18). Plants from 33 populations were sampled for measuring the ploidy level and 27 morphological characters for morphological analysis. Two ploidy levels were confirmed in the Czech Republic and a new late flowering tetraploid taxon (2n = 4x = 40) was found. The three taxa were separated from each other based on the seasonal variation, ploidy level, morphology and ecology.

Sturgeons (Chondrostei: Acipenseriformes) display markedly disjunct distributions with a wide occurrence in the northern hemisphere. Their unique benthic specializations, conserved morphology, evolutionary age, the variation in their basic diadromous life history, and the large public interest due to their near extinction or critically endangered status make sturgeons and paddlefishes one of the most interesting group of vertebrates. In addition to that, ploidy diversity of Acipenseriformes possessing three ploidy groups having ~ 120 chromosomes, ~ 240 ? 270 chromosomes and ~ 360 chromosomes provides unique model for investigation of evolutionary processes which were going through the genome duplication events. Sturgeons are also notoriously known for their strong propensity to interspecific and intergeneric hybridization which can result in hybrids with various ploidy levels. All these facts make sturgeon genetics and cytogenetics a thriving but also complicated area for research. In the present work, the role of genome duplication and functional reduction evens in evolution of sturgeon species as well as sturgeons? ploidy levels and ploidy relationships among Acipenseriformes were investigated using molecular markers. In addition to that, clarification of origin of abnormal ploidy levels and observation of segregation pattern of microsatellite alleles in the course of hybridization of polyploid sturgeon species were included into this study. With regard to the all considerations and observations provided by this study we concluded that evolution of sturgeon species is still widely dynamic and ongoing process which might goes through the allopolyplodization as well as autopolyplidization events.

ABSTRACT Three different genotypes of sugar beet (diploid, triploid and tetraploid) / 4 varieties from diploid and triploid genotypes Soraya (KWS8123) and Leila (diploid), Visa (H68121) and Kassandra (triploid) and 2 lines from tetraploid genotype &Ccedil / BM315 and EA2075 (tetraploid) were used for investigating the effects of ploidy level on plant regeneration. Within three sugar beet genotypes, with respect to the treatments, triploids or tetraploids were found to respond to treatments significantly different when compared with diploids. The responses of polyploids were superior over the responses of diploids. Moreover, varieties from same genotype responded differently to treatments. Two types of calli were obtained / one white and friable with regenerative capacity and the other green and compact with no regenerative capacity. Concentration of sucrose on callus development was observed to be important. High concentration of sucrose (30 g/L) was found to cause discoloration and irresponsiveness of formed calli at callus enlargement and subsequent shoot regeneration stages. Therefore, low concentration (10 g/L) is advised to be used at these stages / although this caused less callus induction. Although initially used for the prevention of tissue discoloration, L-ascorbic acid inclusion into the medium was found to be positively affecting the regeneration capacity. When used at 20 mg/100 mL concentration, the only two spontaneous shoots from the tetraploid EA2075 line were obtained. Subsequently, these shoots were successfully rooted and whole plants were obtained. The effect of silver nitrate, in combination with L-ascorbic acid, on the prevention of sugar beet tissue discoloration was investigated. Unfortunately, the symptoms of discoloration did not diminish. Moreover, callus formation was reduced and the subsequent shoot recovery could not be achieved. Since a total of 3456 explants were used during this study, and only 2 whole plants were regenerated, the efficiency of plant recovery was calculated as a rather low value of 0.058 %.

<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>

Made available in DSpace on 2015-03-26T13:42:26Z (GMT). No. of bitstreams: 1 texto completo.pdf: 881362 bytes, checksum: 0e498263c87a06e3c091110afa80ddfe (MD5) Previous issue date: 2012-07-17 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Tissue culture techniques are often associated with the occurrence of somaclonal variation, characterized by a genetic/epigenetic alteration found in cells, embryos, organs or in vitro grown plants, due to stress conditions imposed by the system. The propagation process involving the calogenesis step has a higher susceptibility to variation, because of many cell divisions. Calli are disorganized cell masses, whose cells divide at different rates depending on where they are located in relation to the culture medium, therefore, they are not considered homogeneous materials. Flow cytometry is a tool that has been used to evaluate the competence of somatic embryogenesis in callus, both to identify the different types as possible and to detect early changes in DNA content of their cells. However, there are no reports in the literature of the flow cytometry use to determine the existence of heterogeneity in relation to the DNA content in callus. In this perspective, the present work adapted this methodology for friable Passiflora cincinnata calli in order to verify the existence of vertically regionalized heterogeneity in relation to DNA ploidy level, and relate it to factors inductors of somaclonal variation, such as cultivation time and subculture numbers. Initially, P. cincinnata cotyledonary leaves were inoculated onto semi-solid medium containing 2, 4-D and BA, for friable embryogenic callus induction. The calli were multiplied and subcultured at different times, thus generating three callus types: new, intermediate and old. Twenty calli of each type were subjected to sagittal cuts resulting two layers (I, II) in new calli, and three layers (I, II and III) in intermediate and old calli, totalizing 160 layers, which were analyzed by flow cytometry. Six different DNA ploidy levels and multiploidies were detected in the layers. In new calli, 25% were heterogeneous, i.e. at least one callus layer showed different DNA ploidy level from the others, differently from intermediate and old calli, which 75% and 63% were heterogeneous, respectively. The homogeneous new calli were predominantly diploid. The highest DNA ploidy levels were observed in the layers in contact with the culture medium on intermediate calli, and 4C and 4C/8C cells were more evident in older calli. These observations suggest that the appearance of new DNA ploidy levels between the layers and between the different callus types is related to the exposure time to the medium containing relatively high concentration of 2,4-D. It was also possible to verify that the layer in contact with the culture medium is more proliferative when compared the percentages of the G2 peaks in homogeneous diploid calli. The heterogeneity in DNA ploidy level between the layers was observed, and it implies that parts of a callus cannot infer about a whole callus. This work suggests that time influences the appearance of different DNA ploidy levels in calli induced in vitro. / Técnicas de cultura de tecidos estão frequentemente associadas com a ocorrência de variação somaclonal, caracterizada pela alteração genética e/ou epigenética encontrada em células, embriões, órgãos ou plantas cultivadas in vitro, em decorrência das condições de estresse impostas pelo sistema. O processo de propagação que envolve a etapa de calogênese apresenta maior susceptibilidade à ocorrência de variação, em função das inúmeras divisões celulares. Calos são massas celulares não organizadas, cujas células se dividem a diferentes velocidades dependendo de onde se localizam em relação ao meio de cultura; portanto, não são considerados materiais homogêneos. A citometria de fluxo é uma ferramenta que tem sido utilizada para avaliar a competência da embriogênese somática em calos, tanto para identificar seus diferentes tipos quanto para detectar precocemente possíveis alterações no conteúdo de DNA de suas células. No entanto, não há relatos na literatura da utilização da citometria de fluxo para verificar a existência da heterogeneidade quanto ao conteúdo de DNA em calos. Nesta perspectiva, o presente trabalho adaptou essa metodologia para calos friáveis de Passiflora cincinnata, a fim de verificar a existência de heterogeneidade verticalmente regionalizada, em relação à ploidia de DNA, e relacioná-la com fatores de indução de variação somaclonal, como tempo de cultivo e número de subcultivos. Inicialmente, folhas cotiledonares de P. cincinnata foram inoculadas em meio semissólido contendo 2,4-D e BA, para indução de calos embriogênicos friáveis. Os calos foram multiplicados e subcultivados em diferentes tempos, gerando, assim, três tipos de calos, denominados como novos, intermediários e velhos. Vinte calos de cada tipo foram submetidos a cortes sagitais que resultaram duas camadas (I e II) em calos novos, e três camadas (I, II e III) em calos intermediários e velhos, totalizando 160 amostras que foram analisadas por citometria de fluxo. Seis diferentes ploidias de DNA e multiploidias foram detectadas nas camadas. Em calos novos, 25% deles foram heterogêneos, ou seja, pelo menos uma camada apresentou nível de ploidia de DNA diferente das demais, diferentemente dos calos intermediários e velhos, os quais 75% e 63% foram heterogêneos, respectivamente. Os calos novos homogêneos foram predominantemente diploides. As ploidias de DNA mais altas foram observadas nas camadas em contato com o meio de cultura em calos intermediários, e células 4C e 4C/8C foram mais evidentes em calos velhos. Essas observações sugerem que o surgimento de novos níveis de ploidia entre as camadas e entre os calos de diferentes tipos está relacionado com o tempo de exposição ao meio contendo concentração relativamente alta de 2,4-D. Foi possível, também, verificar que a camada em contato com o meio é mais proliferativa quando se comparou os percentuais dos picos G2 de calos diploides homogêneos. A heterogeneidade quanto ao nível de ploidia de DNA entre as camadas foi constatada e isto implica que partes de um calo não podem inferir sobre um calo inteiro. Esse trabalho sugere que o tempo influenciou o surgimento de diferentes ploidias de DNA em calos induzidos in vitro.

Presence and range of phenotypic plasticity in the Agrostis stolonifera polyploid complex (Poaceae) was studied in the territory of the Czech Republic. Plants were cultivated under different experimental conditions. Stomatal size of different Agrostis stolonifera cytotypes was measured. Flow cytometry was applied for genome size estimation. Ploidy levels were determined for more than 150 samples of Agrostis stolonifera as well as several specimens of Agrostis canina, A. capillaris, A. gigantea, A. rupestris and A. vinealis. Absolute DNA content was estimated in all studied species. Isozyme analysis was used to test the possibility of the hybrid origin of pentaploid individuals of Agrostis stolonifera species.

The Japanese knotweeds are invasive alien clonal species originating in Asia (Japan, Korea, Taiwan and Nord of China). They were introduced in Europe at the beginning of the 19th century. They are now some of the most troublesome invasive alien species in Europe and in the United States. In Belgium, a complex of four taxa and a hybrid represents them. All these taxa take part in the pattern of invasion and represent an excellent opportunity for studies of population biology in Western continental Europe. The presence from at least three taxa and a hybrid is confirmed by cytological, genetic and morphological studies. Vegetative reproduction is recognized as the main mode of reproduction and expansion of these taxa in the introduce range. However, interspecific hybridization events are observed confirming the restoration of the sexual reproduction by hybridization within this complex species in Belgium. Hybrid F. x bohemica with various ploidy levels from tetraploid to octoploid is observed. An increase in genotypic and morphological diversity is shown at the hybrid F. x bohemica which missed with the parental species. This could increase the potential of Japanese knotweeds to adapt to the new environment and contribute to the invasive success of these taxa in Belgium. Assignment test indicates a genetic pool differentiated at the hybrid F. x bohemica and not a mixture of the genetic pool of the parental species as expected for hybrid taxa. Hybrid F. x bohemica has always been considered as rare in Belgium and of horticultural origin. An analysis of the spatial distribution shows that hybrid F. x bohemica is widespread in Belgium and that its abundance depends on the areas. An analysis of extent of differentiation between groups of hybrid geographically distant could not provide proof of an independent evolution of hybrid populations under limited gene flow. An analysis of the sexual reproduction capacity and dispersal of seeds shows important production of viable seeds and consequent seed rain. Hybrid seeds may be dispersed beyond 16m, leading the possibility of founding new individuals and to contribute to the invasive success of these taxa. However, a trend towards decreasing germination rate is shown after a cold period. An analysis of the distribution at the landscape scale shows that the dynamics of colonization of habitats patches by Japanese knotweeds rising mainly from clonal propagation in spite of important pressure of propagule. The knotweeds prefer human disturbed habitats with a clear prevalence of communication routes. This leads the possibility of dispersing towards the adjacent habitats patches. A high dynamics of establishment of propagule was not observed at the hybrid plants compared with the parents plants in spite of the increase in genotypic diversity and the consequent pressure of propagule. Lastly, proposals for the integrated management of these taxa are proposed in the Belgium context. Their management will have first to identify hybrids and taxa involved. Emasculation and management of the existing clones represent solutions to prevent flowering and expansion of these taxa. An active management of disturbed habitats may represent alternative to prevent the invasion by Japanese knotweeds / Les renouées du Japon sont des espèces clonales non-indigènes originaires dAsie (Japon, Corée, Taiwan et Nord de la Chine). Elles ont été introduites en Europe au début du 19è siècle. Elles font désormais partie des espèces non-indigènes les plus invasives en Europe et aux Etats Unis. En Belgique, elles sont représentées par un complexe de quatre taxons et un hybride. Tous ces taxons participent à la dynamique dinvasion et représentent un modèle dintérêt pour les études de biologie des populations en Europe continentale occidentale. La présence dau moins trois taxons et un hybride est confirmée par des études cytologiques, génétiques et morphologiques. La reproduction végétative est reconnue comme le principal mode de reproduction et dexpansion de ces taxons dans la zone dintroduction. Toutefois, des phénomènes dhybridation interspécifique sont observés confirmant la restauration de la reproduction sexuée par hybridation au sein de ce complexe despèces en Belgique. Lhybride F. x bohemica avec différents niveaux de ploïdie, du tétraploïde à loctoploïde, est observé. Un accroissement de la diversité génotypique et morphologique qui manquait aux espèces parents est démontré chez lhybride F. x bohemica. Ceci pourrait augmenter le potentiel des renouées du Japon à sadapter au nouvel environnement et contribuer au succès invasif de ces taxons en Belgique. Un test dassignation indique un pool génétique différencié chez lhybride F. x bohemica et non un mélange du pool génétique des espèces parentales comme attendu dans le cadre de taxons hybrides. Lhybride F. x bohemica a toujours été considéré comme rare en Belgique et dorigine horticole. Une analyse de la répartition spatiale montre que lhybride F. x bohemica est très répandu en Belgique et que son abondance dépend des régions. Une analyse de létendue de la différenciation entre groupes dindividus hybrides géographiquement distants na pas pu fournir de preuve dune évolution indépendante des populations hybrides sous un flux de gènes limité. Une analyse de la capacité de reproduction sexuée et de dispersion des graines démontre une production importante de graines viables et une pluie de graines conséquente. Les graines hybrides sont capables de se disperser à plus de 16m, laissant la possibilité de fonder de nouveaux individus et de contribuer au succès invasif de ces taxons. Cependant, une tendance à la diminution du potentiel de germination est observée après une période de froid chez ces taxons. Une analyse de la distribution à léchelle du paysage a permis dinterpréter la dynamique de colonisation des taches dhabitats par les renouées du Japon comme relevant principalement de la propagation clonale malgré une pression de propagule importante. Les renouées du Japon préfèrent les habitats perturbés par lhomme avec une nette prédominance des réseaux linéaires de communications. Ceci laisse ensuite la possibilité de se disperser vers les taches dhabitats adjacents. Une dynamique détablissement de propagules plus importante na pas été observée chez les plants hybrides comparées aux plants parents malgré laccroissement de diversité génotypique et la pression de propagules considérable. Enfin, des pistes pour la gestion intégrée des renouées du Japon en Belgique sont proposées. Cette gestion devra en priorité identifier les hybrides et les taxons en présence. Des mesures démasculation et de gestion des clones existants pourraient constituer une solution pour empêcher la floraison et lexpansion de ces taxons. Une gestion active des habitats perturbés pourrait représenter une alternative pour prévenir linvasion par les renouées du Japon