xii, 226 leaves : photos., tables, graphs ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Plant Physiology, 1978

Thesis (Ph.D.) -- University of Adelaide, Dept. of Plant Physiology, 1978.

Thesis (Ph. D.)--University of Chicago, 1920. / "Private edition, distributed by the University of Chicago libraries, Chicago, Illinois, 1921." "Reprinted from the Botanical gazette, vol. LXXII, no. 1, July, 1921." "Literature cited": p. 29-30. Also available on the Internet.

Dormancy in many aquatic angiosperms is characterized by the production of turions, specialized vegetative buds which function as both propagules and perennating organs. In temperate climate species, induction of dormancy is usually associated with short days, often in conjunction with low temperatures. By contrast, the turions of Potamogeton crispus are formed around midsummer and the species grows luxuriantly throughout the winter. The environmental factors controlling turion formation in Potamogeton crispus were investigated under natural and laboratory conditions. Potamogeton obtusifolius, a typical temperate climate species exhibiting autumnal turion production, was studied for comparative purposes. Phenological development of natural populations in two Scottish lakes was compared with seasonal measurements of temperature, daylength, underwater light attenuation and light quality (the red and far red wavelength bands). Temperature and photoperiod were identified as the primary environmental factors regulating turion formation in both species. Laboratory experiments confirmed the field observation that turions are produced by Potamogeton crispus in response to long days (greater than 12 to 16h) and high temperatures (greater than 16°C). In Potamogeton obtusifolius, turion production is associated with short days and high temperatures. Because of the complexity of the underwater light climate, the effect of light quantity (irradiance) and light quality on turion production could not be determined. Laboratory experiments showed that under inductive photoperiodic and temperature conditions, low red:far red ratios and low irradiance inhibited turion formation in Potamogeton crispus. The action of phytochrome in the perception of the long day photoperiodic signal and the quantitative effect of sucrose concentration on the magnitude of turion production in Potamogeton crispus was investigated. A model of phytochrome action in the control of photoperiodic and photomorphogenetic responses in aquatic angiosperms is presented and the role of turions in the life history of Potamogeton crispus and Potamogeton obtusifolius is assessed.

Graduation date: 1997

No description available.

Thesis (Ph.D.)--University of Western Australia, 2006.

Thesis (M.S.)--University of Wisconsin--Madison, 1965. / eContent provider-neutral record in process. Description based on print version record. Bibliography: l. 62-63.

Made available in DSpace on 2014-06-11T19:30:26Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-02-25Bitstream added on 2014-06-13T21:01:06Z : No. of bitstreams: 1 000755167.pdf: 2367968 bytes, checksum: 406c0b563423541bacf6a7c59f70fbe2 (MD5) / A ocorrência de dormência se opõe ao pleno sucesso da propagação futura das espécies nativas de interesse para fins comerciais. Assim, o principal objetivo é o estudo fisiológico e molecular de sementes (embrião) de Annona crassiflora durante a superação da dormência morfofisiológica natural no campo. As sementes foram coletadas de áreas do cerrado do Estado de Minas Gerais, secas em temperatura entre 20-25ºC, em condições de laboratório, até atingirem umidade de 10% com base úmida. Foram feitas no mesmo lote de sementes a determinação da curva de embebição em água, germinação em campo, teor de água e crescimento do embrião mensal. As sementes foram colocadas em sacos de poliester com orifícios de 0,5 cm de diâmetro e, enterradas no mês de abril. Em paralelo, sementes foram colocadas para embeber em solução de giberelina (GA4) na concentração de 100μM, por oito dias e tiveram o comprimento do embrião e teor de água avaliados. Em novembro, as sementes enterradas a campo foram desenterradas e as que apresentaram rupturas no tegumento (sem protrusão radicular) tiveram o embrião isolados para a extração de RNA. Em seguida a integridade do RNA foi verificada em Bioanalyzer (Agilent 2100) e as bibliotecas foram preparadas utilizando o protocolo TruSeq RNA sample prep v2. O sequenciamento foi realizado no HiScanSQ (Illumina) e os dados gerados analisados pelo plataforma CLC Genomics Workbench versão 6.0.2 (CLC bio, Denmark) para montagem do transcriptoma referência e quantificação da expressão por valores de RPKM (Reads per Kilobase per Million of mapped reads). Os contigs foram anotados usando o programa BLAST2Go e manualmente. A semente de A. crassiflora estava totalmente embebida em torno de sete dias de embebição e o teor de água variou de acordo com as condições de umidade do solo, sendo maior no período de germinação. O crescimento do embrião iniciou-se... / The occurrence of dormancy opposes to the success of the future propagation of species. Thus, the objective of this study was to performe physiological and molecular studies em seed of Annona crassiflora during overcoming morphological dormancy under field onditions. The seeds were collected from areas of the Cerrado biome from the Minas Gerais State, dried at room temperature until the moisture content of 10% on wet basis. The imbibtion curve, germination in the field, water content and growth of the embryo were made in the same batch of seeds. The seeds were placed in polyester bags with holes of 0.5 cm diameter, buried in April. In parallel, seeds were also imbibed in gibberellin (GA4) at a concentration of 100μM during seven days and had the embryo length measured. In October, embryos were isolated from seeds showing growth of the embryo but without radicle protrusion for RNA extraction. The integrity of the RNAs was verified in Bioanalyzer (Agilent 2100). Following, cDNA libraries were prepared using the TruSeq RNA sample prep protocol v2. Sequencing was performed in HiScanSQ (Illumina) and the analyses of the data was performed by using the CLC Genomics Workbench platform version 6.0.2 (CLC bio, Denmark) for transcriptome assembly and quantification of the expression values for RPKM (Reads per kilobase per Million of mapped reads). The contigs were anotados using the program BLAST2Go and manually. The seed is fully imbibed at seven days imbibitions, and the water content varies with soil conditions being higher during germination. The growth of the embryo starts in August and maintained until January, with peak of germination observed in November. After this period, the seeds that did not germinate formed a soil seed bank and there was no growth of the embryo. After 28 days from the start of imbibitions in GA4 the first seeds showed testa rupture indicating growth of the embryo. From the ...

Orientador: Edvaldo Aparecido Amaral da Silva / Banca: Juliana Pereira Bravo / Banca: Adriana Rodrigues Passos / Banca: João Nakagawa / Banca: Alessandro de Mello Varani / Resumo: A ocorrência de dormência se opõe ao pleno sucesso da propagação futura das espécies nativas de interesse para fins comerciais. Assim, o principal objetivo é o estudo fisiológico e molecular de sementes (embrião) de Annona crassiflora durante a superação da dormência morfofisiológica natural no campo. As sementes foram coletadas de áreas do cerrado do Estado de Minas Gerais, secas em temperatura entre 20-25ºC, em condições de laboratório, até atingirem umidade de 10% com base úmida. Foram feitas no mesmo lote de sementes a determinação da curva de embebição em água, germinação em campo, teor de água e crescimento do embrião mensal. As sementes foram colocadas em sacos de poliester com orifícios de 0,5 cm de diâmetro e, enterradas no mês de abril. Em paralelo, sementes foram colocadas para embeber em solução de giberelina (GA4) na concentração de 100μM, por oito dias e tiveram o comprimento do embrião e teor de água avaliados. Em novembro, as sementes enterradas a campo foram desenterradas e as que apresentaram rupturas no tegumento (sem protrusão radicular) tiveram o embrião isolados para a extração de RNA. Em seguida a integridade do RNA foi verificada em Bioanalyzer (Agilent 2100) e as bibliotecas foram preparadas utilizando o protocolo TruSeq RNA sample prep v2. O sequenciamento foi realizado no HiScanSQ (Illumina) e os dados gerados analisados pelo plataforma CLC Genomics Workbench versão 6.0.2 (CLC bio, Denmark) para montagem do transcriptoma referência e quantificação da expressão por valores de RPKM (Reads per Kilobase per Million of mapped reads). Os contigs foram anotados usando o programa BLAST2Go e manualmente. A semente de A. crassiflora estava totalmente embebida em torno de sete dias de embebição e o teor de água variou de acordo com as condições de umidade do solo, sendo maior no período de germinação. O crescimento do embrião iniciou-se... / Abstract: The occurrence of dormancy opposes to the success of the future propagation of species. Thus, the objective of this study was to performe physiological and molecular studies em seed of Annona crassiflora during overcoming morphological dormancy under field onditions. The seeds were collected from areas of the Cerrado biome from the Minas Gerais State, dried at room temperature until the moisture content of 10% on wet basis. The imbibtion curve, germination in the field, water content and growth of the embryo were made in the same batch of seeds. The seeds were placed in polyester bags with holes of 0.5 cm diameter, buried in April. In parallel, seeds were also imbibed in gibberellin (GA4) at a concentration of 100μM during seven days and had the embryo length measured. In October, embryos were isolated from seeds showing growth of the embryo but without radicle protrusion for RNA extraction. The integrity of the RNAs was verified in Bioanalyzer (Agilent 2100). Following, cDNA libraries were prepared using the TruSeq RNA sample prep protocol v2. Sequencing was performed in HiScanSQ (Illumina) and the analyses of the data was performed by using the CLC Genomics Workbench platform version 6.0.2 (CLC bio, Denmark) for transcriptome assembly and quantification of the expression values for RPKM (Reads per kilobase per Million of mapped reads). The contigs were anotados using the program BLAST2Go and manually. The seed is fully imbibed at seven days imbibitions, and the water content varies with soil conditions being higher during germination. The growth of the embryo starts in August and maintained until January, with peak of germination observed in November. After this period, the seeds that did not germinate formed a soil seed bank and there was no growth of the embryo. After 28 days from the start of imbibitions in GA4 the first seeds showed testa rupture indicating growth of the embryo. From the ... / Doutor