Submitted by Reginaldo Soares de Freitas (reginaldo.freitas@ufv.br) on 2017-10-09T11:45:21Z No. of bitstreams: 1 texto completo.pdf: 9861287 bytes, checksum: d1920707baa642d6539a70010fd3dadd (MD5) / Made available in DSpace on 2017-10-09T11:45:22Z (GMT). No. of bitstreams: 1 texto completo.pdf: 9861287 bytes, checksum: d1920707baa642d6539a70010fd3dadd (MD5) Previous issue date: 1997-02-21 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Três meios de cultivo foram testados com o objetivo de avaliar o mais indicado para o desenvolvimento e crescimento das variedades Baraka, Bintje e Contenda. Utilizaram-se o meio MS suplementado com sacarose 3% e vitaminas, o meio MS com sacarose 3%, vitaminas e ácido giberélico 1,4 umol/ L e o meio MS modificado. O delineamento experimental utilizado foi inteiramente casualizado, com seis repetições e cinco plantas por parcela. Plãntulas no meio MS + GAs apresentaram a maior média de número de folhas definitivas e também maior média de comprimento de parte aérea para todas as variedades. Para determinar a concentração ideal de picloram à indução de calejamento, um experimento foi realizado, testando-se as seguintes concentrações: 0,0; 0,0165; 0,165; e 1,65 pmol/L por 32 dias. O melhor resultado foi obtido com 1,65 pmol/ L. Calos foram induzidos, usando-se folha e caule como explantes das variedades comerciais Baraka, Bintje, Contenda, Baronesa e Achat em meio MS suplementado tanto com picloram 1,65 “mol/L quanto com 2,4-D 11,5 umol/L. Após 70 e 90 dias de calejamento, os DNAs das 40 amostras de calos foram analisados num estudo comparativo entre as duas fontes de explantes das cinco variedades e de ambos os reguladores de crescimento. Para isso, 20 “primers” de sequência arbitrária foram testados. Para a variedade Baraka, caule como explante, picloram e 90 dias de calejamento foram os tratamentos que induziram a maior variação somaclonal. Para Bintje, os tratamentos foram folha, picloram e 70 dias. Dos 20 “primers” testados, 14 apresentaram polimorfismo para a variedade Contenda quando submetida ao tratamento que utilizou caule como explante, picloram e 70 dias de calejamento. Dentre os genótipos analisados, a variedade Baronesa apresentou o maior número de fragmentos polimórficos para todos os tratamentos. A variedade Achat mostrou-se mais suscetível a variação somaclonal quando submetida aos tratamentos que utilizaram 2,4-D, 90 dias de calejamento e tanto caule e folha como explante. O maior tempo de cultivo não teve grande influência na variação somaclonal da maioria das variedades, exceto “Baraka” e “Achat'. O fator genótipo foi o mais importante, pois cada variedade teve desempenho distinto do das outras, no que concerne à taxa de variação somaclonal. / No sumario consta o abstract, mas a pagina não esta na tese.

The genus Populus is ideally suited to investigate questions related to the interplay between an individual’s environmental history and its capacity to respond to external stimuli. In order to dissect the influence of individual history on subsequent plant responses, transcriptome level changes due to water deficit were assessed in clonal populations of Populus hybrids. Results indicate variation in the drought transcriptomes of genetically identical clones originating from different locations can be shaped by the individual history of the clone. Additionally, yearly variations in drought transcriptome patterns showed specific trends associated with a clonal population that were not related to an unknown influence at a location, nor with the biological source of cuttings. Despite these sources of transcriptome variation, a common shared response was identified across all populations. The findings hint at the influence of the environment and epigenetic factors in the dynamic regulation of transcriptome level responses in clonal individuals.

The genus Populus is ideally suited to investigate questions related to the interplay between an individual’s environmental history and its capacity to respond to external stimuli. In order to dissect the influence of individual history on subsequent plant responses, transcriptome level changes due to water deficit were assessed in clonal populations of Populus hybrids. Results indicate variation in the drought transcriptomes of genetically identical clones originating from different locations can be shaped by the individual history of the clone. Additionally, yearly variations in drought transcriptome patterns showed specific trends associated with a clonal population that were not related to an unknown influence at a location, nor with the biological source of cuttings. Despite these sources of transcriptome variation, a common shared response was identified across all populations. The findings hint at the influence of the environment and epigenetic factors in the dynamic regulation of transcriptome level responses in clonal individuals.

Die vorliegende Arbeit befasst sich mit den morphologischen bzw. cytologischen Anomalien eines mutierten Klons 5/74/2 aus der haploiden Sorte `Kleiner Liebling` von Pelargonium zonale. An histologischen Schnitten wurden die Ploidiestufen verschiedener Zellschichten von Cytochimären durch Chromosomenzählung direkt bestimmt. Es wurde festgestellt, dass die Epidermis in den Blättern vom Klon 5/74/2 verschiedene Ploidiestufen aufweist. Solche Variabilität trat in den L2- und L3-bürtigen Zellschichten nicht auf. Somit wurde hier erstmals eine Periklinalcytochimäre mit verschiedenen Ploidie in der Epidermis nachgewiesen. Es zeigte aber zwei unterschiedliche Zustände im Sprossscheiteln: Beim ersten sind die Zellen der L1 Polyploidie. Beim zweiten sind die Zellen der L1 haploid. Die Polyploidisierung der Epidermis setzt sich bei dem Wachstum des Blattes fort. Bei den cytologischen Untersuchungen wurden anomale Mitosen mit irregulären Chromsomenanordnungen (multipolare) und mehrkernige Zellen in der Epidermis beobachtet. Als weitere Anomalie traten eingeschnürte Zellkerne in den Epidermiszellen auf. Die Pflanzen mit stark behaarten und gekräuselten Blättern vom Klon 5/74/2 waren nicht stabil. Die Epidermis des gekräuselten und stark behaarten Blattes enthielt wie die des stark behaarten Blattes oder die des gekräuselten Blattes verschiedene Ploidiestufe. Die Epidermiszellen der meisten Pflanzen mit normal glatten Blättern lagen im diploiden Bereich. Die morphologische Kräuselung und Behaarung hing mit dem Auftreten der somatischen Variabilität in Epidermis von Klon 5/74/2 zusammen. Adventivpflanzen mit Hilfe eines modifizierten Mediums aus Kallus von Pelargonium zonale sind in in vitro-Kultur zu regenerieren. Dabei zeigte die Zugabe von Perlit und anschließend PVP die beste Wirkung gegen die Bildung von Polyphenolverbindungen im Pelargonium-Gewebe. TDZ ist einer der effektivsten Wuchsstoffe für die Kallusinduktion und Regeneration der Adventivsprosse bei Pelargonium. Die Blatt- und die Blütenfarbe der Adventivpflanzen aus dem dreifach markierten chimärischen `Weißer Liebling` (WRR, GWG, DHH) stimmten mit dem Genotyp der L1-Zellen überein. Die Stomatalängen der Adventivpflanzen aus dem Klon 5/74/2 (PHH) lagen wie die von `Weißer Liebling` (DHH) meistens im Bereich von diploid, nur selten von tetraploid oder gemischten. Die ursprünglich polyploiden und haploiden Zellen der kultivierten Gewebe traten nach der Regeneration nicht mehr auf. Dies weist auf eine Zellmutation und -selektion während der in vitro-Kultur hin. Aus chimärischen Geweben der GWG- und GGW-Varianten von `Mrs. Pollock` wurden 8,6% Adventivsprosse mit neuen chimärischen Blattmustern regeneriert. Das Ergebnis zeigt, dass die Zellen mindestens in L2 und L3-bürtigen Gewebeschichten der Explantaten zur Regeneration der Adventivsprossen teilgenommen haben. / A mutated clone with different ploidy levels in epidermis cells, 5/74/2, of the haploid `Kleiner Liebling` of Pelargonium zonale was investigated to answer the question that how the different ploidy levels were generated. Such a variability did not appear in L2- and L3-derived cells. Consequently, clone 5/74/2 is a periclinal cytochimera with a mixed ploidy epidermis. This type of cytochimera with different ploidy levels in epidermis has not been reported up to now. The epidermis of the blistered leaf or of the hairy leaf is polyploid with different ploidy levels, like the epidermis of the shoots with blistered and hairy leaves. Epidermis cells of normal shoots are diploid. The morphologically blistered leaf surface seems to be the result of a somatic variability in epidermis. Histological investigations of clone 5/74/2 showed two different ways of development of the somatic variability: the cells of the L1 in the apical meristem were already polyploid and the cells in the apical meristem were haploid. Cytological analyses revealed anomalies of the mitosis in epidermis cells of clone 5/74/2. Various irregular chromosomal arrangements (multipolar mitosis) and polynuclear cells were observed. Additionally, nuclei with constrictions were found. Adventitious shoots were successfully regenerated from callus of adult tissue of Pelargonium in vitro on modified medium. The combination of Perlit and PVP showed the best effects against the formation of phenolic substances on Pelargonium tissues during in vitro-culture. TDZ was the most effective substance for callus induction and regeneration of adventitious shoots. The colour of leaves and flowers in the adventitious plants regenerated from tissue of the triply marked chimera ’Weißer Liebling’ (GWG, WRR, DHH) were correlated with the genotype of L1. However, somaclonal variability of ploidy levels was observed. The size of stomata on adventitious plants from the clone 5/74/2 (PHH) was similar to from DHH-tissue, mostly in the range of diploid, only rarely in tetraploid or mixed ploidy. Derivates of the original polyploid and haploid cells of the cultivated tissue were not found. Evidently, cell selection and mutation occurred during the in vitro-culture. 8.6% Adventitious shoots with new chimeral patterns were regenerated from chimeral GWG- and GGW-explants of Pelargonium zonale `Ms. Pollock`. More chimeras from GGW explants were obtained than from GWG explants. This result showed that cells in both L2 and L3 derived tissues of the explants were involved in the regeneration of the adventitious shoots.