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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Veiksniai, lemiantys Sedum L. pridėtinių ūglių formavimąsi in vitro / Factors determining adventitious shoot formation in vitro in Sedum L

Klimaitienė, Erika 13 June 2012 (has links)
Magistrantūros studijų baigiamajame darbe pateikiama šilokų pridėtinių ūglių regeneracija lapų segmentų kultūroje, priklausomai nuo genotipo ir augimo reguliatorių maitinamojoje terpėje. Darbo objektas – Sedum rupestre ‛Angeline’, Sedum reflexum ‛Cristatum’, Sedum fosterianum ‛Elegans’, Sedum maximum ‛Autumn Joy’ lapų audiniai. Darbo metodai: izoliuoti eksplantai auginti Murashige ir Skoog (MS) maitinamojoje terpėje su skirtingais augimo reguliatorių kiekiais. Susiformavę pridėtiniai ūgliai įšaknydinti MS maitinamojoje terpėje su skirtingais augimo reguliatorių kiekiais. Vertintas ūglių susiformavimo dažnis (%), ūglių kiekis iš eksplanto (vnt.) ir įsišaknijimo dažnis (%). Darbo rezultatai. Veislių ‛Elegans’ ir ‛Cristatum’ ūglių susiformavimo dažnį labiausiai skatino 0,75 mg l-1 BAP. Veislės ‛Angeline’ didžiausias ūglių susiformavimo dažnis nustatytas terpėje, papildytoje 3,0 mg l-1 BAP. Veislės ‛Autum joy’ izoliuoti lapo segmentai 100 % dažniu ūglius formavo terpėse su 3,0 mg l-1 BAP + 0,5 mg l-1 NAR ir 4,0 mg l-1 BAP + 0,5 mg l-1 NAR. Veislės ‛Elegans’ didžiausias ūglių kiekis eksplantui gautas terpėje papildytoje 0,75 mg l-1 BAP. Veislės ‛Angeline’ daugiausia ūglių iš eksplanto susiformavo terpėse su 0,75 mg l-1 BAP ir 3,0 mg l-1 BAP. Terpėje, papildytoje 3,0 mg l-1 BAP gautas didžiausias veislės ‛Cristatum’ ūglių kiekis vienam eksplantui. Veislės ‛Autum joy’ eksplantai daugiausia ūglių suformavo terpėse, papildytose 3,0 mg l-1 BAP + 0,5 mg l-1 NAR ir 4,0 mg l-1 BAP + 0,5... [toliau žr. visą tekstą] / The master work presents orpine adventitious shoots regeneration in leaves segments cultures, depending on genotype and growth regulators in the culture medium. Object of the work – Sedum rupestre ‛Angeline’, Sedum reflexum ‛Cristatum’, Sedum fosterianum ‛Elegans’, Sedum maximum ‛Autumn Joy’ leaves tissues. Method of the work – isolated explants were growing on Murashige ir Skoog (MS) nutrition medium with different content of growth regulators. Adventitious shoots were transferred to MS culture medium for rhizogenesis induction. Shoots formation frequency, number of shoots per explant and rooting frequency were evaluated. The results of work. The highest shoots formation frequency of orpine varieties ‛Elegans’ and ‛Cristatum’ has been obtained under influence of 0.75 mg l-1 BAP. The 3.0 mg l-1 BAP concentration in culture medium resulted in highest shoots regeneration frequency of variety ‛Angeline’. All isolated explants of ‛Autum joy’ formed adventitious shoots in the medium supplemented with 3.0 mg l-1 BAP + 0.5 mg l-1 NAA and 4.0 mg l-1 BAP + 0.5 mg l-1 NAA. While 0.75 mg l-1 BAP in culture medium stimulated shoots formation frequency of variety ‛Elegans’. The highest shoots number per explant of variety ‛Angeline’ has been establishing in medium with 0.75 mg l-1 BAP and 3.0 mg l-1 BAP. Medium supplemented with 3.0 mg l-1 BAP resulted in highest shoots number per explant of ‛Cristatum’. Explants of variety ‛Autum joy’ highest shoots number per explant formed in medium... [to full text]
2

Reversão à juvenilidade em Passiflora edulis SIMS / Reversion to juvenility in Passiflora edulis SIMS

Amorim, Andredy Murilo Trindade 28 February 2019 (has links)
O gênero Passiflora é um excelente modelo para estudos de transição de fase, pois há diferenças morfológicas evidentes entre as plantas nas fases juvenil, adulta vegetativa e adulta reprodutiva. Há relatos de que quando se introduzem ápices de plantas adultas de Passiflora edulis, quer estejam na fase vegetativa ou reprodutiva, em condições de cultivo in vitro, observa-se a regressão à fase juvenil. O objetivo geral deste trabalho foi caracterizar as modificações morfológicas envolvidas na reversão à juvenilidade de ápices caulinares adultos de P. edulis quando cultivados em meio de cultura sem adição de reguladores de crescimento além de avaliar o efeito de reguladores de crescimento no intuito de evitar a reversão à juvenilidade no cultivo in vitro de P. edulis. O trabalho foi desenvolvido a partir da combinação da técnica da micropropagação in vitro e microscopia eletrônica de varredura, sendo dividido em três experimentos: o cultivo in vitro de ápices caulinares em meio MSM sem reguladores de crescimento e análise de amostras em microscópio eletrônico de varredura, cultivo in vitro de ápices caulinares em meio MSM com reguladores de crescimento e cultivo in vitro de ápices caulinares em meio MSM adicionados com BAP na concentração de 10?M com análises de amostras em microscópio estereoscópico. Através de micrografias eletrônicas e imagens estereoscópicas, foi possível caracterizar as fases do desenvolvimento de P. edulis, demonstrando os caracteres morfológicos assim como a manutenção das estruturas cultivadas in vitro. Não foi possível observar o rejuvenescimento in vitro quando ápices caulinares foram cultivados em meio ½ MS ou MSM sem adição de reguladores de crescimento. O rejuvenescimento de ápices caulinares adultos de P. edulis foi obtido a partir do cultivo em meio MSM com adição de 10?M de BAP. Entretanto, o rejuvenescimento foi parcial, pois nem todas as características foram revertidas. A formação de folhas lanceoladas in vitro e o desenvolvimento de brotos adventícios in vitro caracterizaram a reversão à juvenilidade em P. edulis. O meio MSM suplementado com 10 ?M de BAP foi favorável ao desenvolvimento de gemas axilares, além de facilitar a indução do rejuvenescimento dos ápices caulinares. Logo, a reversão à juvenilidade foi alcançada sob as condições in vitro adotadas / The genus Passiflora is an excellent model for phase transition studies because there are obvious morphological differences between plants in the juvenile, adult vegetative and adult reproductive phases. It has been reported that when introducing shoot tips of adult plants of Passiflora edulis, whether in the vegetative or reproductive phase, under in vitro culture conditions, regression to the juvenile phase is observed. The general objective of this work was to characterize the morphological changes involved in the reversion to juvenility of adult shoot tips of P. edulis when grown in culture medium without addition of growth regulators in addition to evaluating the effect of growth regulators in order to avoid reversion to juvenility in the in vitro cultivation of P. edulis. The work was developed from the combination of in vitro micropropagation and scanning electron microscopy, and was divided in three experiments: in vitro culture of shoot tips in MSM medium without growth regulators and analysis of samples in scanning electron microscope; in vitro culture of shoot tips in MSM medium with growth regulators and in vitro culture of shoot tips in MSM medium added with BAP at the concentration of 10?M and analysis of samples under a stereoscopic microscope. Through electronic micrographs and stereoscopic images, it was possible characterize the phases of the development of P. edulis, demonstrating the morphological traits as well as the maintenance of the structures cultivated in vitro. In vitro rejuvenation could not be observed when shoot tips were grown in ½ MS or MSM medium without addition of growth regulators. The rejuvenation of P. edulis adult shoot tips was obtained from the cultivation in MSM medium with the addition of 10?M BA. However, the rejuvenation was partial, since not all the characteristics were reversed. The formation of in vitro lanceolated leaves and the development of in vitro adventitious shoots characterized the reversion to juvenility in P. edulis. The MSM medium supplemented with 10?M BA was favorable to the development of axillary buds, in addition to facilitating the induction of the rejuvenation of the shoot tips. Therefore, the reversion to juvenility was achieved under the in vitro conditions adopted
3

Anatomische, cytologische und histologische Untersuchungen zur somatischen Variation in verschiedenen Teilklonen von Pelargonium zonale "Kleiner Liebling"

Li, Mingyin 14 April 2005 (has links)
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.

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