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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.
31

Factors affecting growth and fruiting of Phaseolus vulgaris L.

Stobbe, Elmer Henry January 1965 (has links)
Experiments were conducted in controlled-environment cabinets to show the effect of temperature and light intensity on the growth and fruiting of snap beans. Leaf weights varied inversely with the temperature, but stem weights and numbers of nodes were not greatly affected by day temperature in the range of 75° to 95°F. Blossoming and pod set were similar at day temperatures of 75° and 85°F but were reduced at 95°F. When day temperature was 95°F, a 60°F night temperature resulted in increased blossoming and pod set compared to 80°F. When pods were harvested at marketable maturity, blossoming in bush beans was cyclic. Plants grown at a light intensity of 1900 foot-candles had a lower fresh and dry weight of leaves, stems, and pods, and fewer blossoms and pods set than plants grown at 2700 and 4000 foot-candles. Field experiments showed that planting dates after May 29 reduced the yield of pods in pole beans. Nitrogen level and row direction did not affect yield of pods in pole beans. Number of pods per plant in pole beans increased directly with the row spacing. Chemical sprays at blossoming caused no increase in yield of pods in pole beans, and only a slight increase in the yield of pods in bush beans. Differences in yields of pods between varieties of bush beans were due differences in the number of pods per plant. / Land and Food Systems, Faculty of / Graduate
32

A study of the influence of electric light used to supplement daylight on oats grown as breeding material in the greenhouse during the winter season.

Lods, Emile A. January 1925 (has links)
No description available.
33

Mathematical modeling and simulation of photosynthetic growth in continuous culture under bicarbonate and light limited conditions

Curless, Craig E. January 1986 (has links)
Call number: LD2668 .T4 1986 C87 / Master of Science / Chemical Engineering
34

Investigation into "bud blast" in the Easter lily (Lilium longiflorum Thunb)

Mason, Michael Regis, 1962- January 1989 (has links)
Ethylene and carbohydrate deprivation were investigated as possible causes of bud abortion in Lilium longiflorum Thunb. Silver thiosulfate (STS) was investigated as an inhibitor of ethylene-induced abortion. Fourteen days of 92.5% irradiance reduction increased bud abortion when plants were exposed to 2.07 mM ethephon. Percent bud abortion was 39% and 60% for plants grown in full irradiance and reduced irradiance, respectively. Ethephon resulted in 54% abortion, regardless of irradiance at 4.15 mM. A 70% irradiance reduction for 14 days did not increase bud abortion when plants were treated with ethephon. STS was applied to plants at visible bud +2 weeks followed by ethephon application 2 days later. Bud abortion was reduced from 69 to 13% with 2 mM STS; the STS x ethephon interaction was significant. STS inhibited ethephon-induced bud abortion when applied at visible bud, 4 weeks prior to ethephon application; However, STS application at flower bud initiation did not prevent/reduce ethephon-induced bud abortion.
35

High light stress in photosynthesis: the role of oxidative post-translational modifications in signaling and repair

Kasson, Tina Michelle Dreaden 08 August 2012 (has links)
Oxidative stress is a natural consequence of photosynthetic oxygen evolution and redox enzyme processes. Trp oxidation to N-formylkynurenine (NFK) is a specific, reactive oxygen species (ROS)-mediated reaction. This thesis work describes the identification and functional characterization of NFK in oxygen evolving Photosystem II (PSII). Although proteomics studies have confirmed NFK modifications in many types of proteins, limited knowledge on the biochemical significance exists. In vitro studies in thylakoids and PSII membranes were used to establish a correlation between oxidative stress, NFK formation, and photoinhibition. The in vivo effect of preventing Trp oxidation to NFK was assessed by site-directed mutation in the cyanobacteria Synechocystis sp. PCC 6803. This work provides insight into the role of NFK in photosynthetic oxygen evolution and photoinhibition. Based on the current knowledge of NFK, ROS, and repair, a new model is described. In this modified model for photoinhibition and repair, NFK plays a role in signaling for turnover of damaged proteins. NFK may play a similar role in replacement of damaged proteins in other systems.
36

Seed germination and plant growth as affected by commercial light spectra screening materials

Montgomery, Carl T. 03 June 2011 (has links)
AbstractSome morphological and physiological changes resulting from prolonged plant growth under plastic screening materials (Lifelite) now being marketed in this country are reported.Lifelite filtered out all light wavelengths between 500 and 580 manometers, lowered the transmission level to 26 percent in the 380 to 500 nanometer range and transmitted up to 62 percent of the wavelengths in the 580 to 700 nanometer range.Lifelite enhanced the germination of spinach seeds, inhibited the germination of lettuce and tomato seeds and had no effect on the germination of cabbage or onion seeds.The only positive morphological change elicited by Lifelite was a considerable increase in stem elongation because of an enlargement of cells. All plants., except cabbage, grown under Lifelite showed a substantial decrease in pigmentation.Ball State UniversityMuncie, IN 47306
37

The effect of sun and shade on the leaves of four coastal tree species.

Kemp, Lynley Claire. January 1992 (has links)
Mimusops caffra, Euclea netetensis, Olea woodiana and Peddiea africana are tree species associated with different successional stages in a coastal dune forest. Saplings of these tree species were established in four different light intensities. These were full sun, 40% shade, 70% shade and 90% shade. The hypothesis proposed that the species from different successional stages are preadapted for a particular light environment and are disadvantaged in other light environments. Growth, morphological, biochemical and physiological aspects of the four species in the four light environments were determined. Growth rates showed no consistent pattern with respect to light intensity. However, most species, irrespective of their successional status, had the best growth response in either 40% or 70% shade treatments. All the species showed typical sun and shade responses for morphological, anatomical and some biochemical characteristics. Photosynthetic responses were complex and showed no relationship between the successional status of the species and the light conditions in which they were grown. There appears to be very little relationship between the growth responses, the measured biochemical and morphological aspects, assimilation rates and the successional status of the species. Light intensity is therefore not the sole driving force of forest succession but one of the many factors that contribute to the overall process. / Thesis - (M.Sc.)-University of Natal, Durban, 1992.
38

Influência da luz e temperatura em cavidades e canais secretores em plântulas de Copaifera langsdorffii Desf. (Leguminosae-Caesalpinioideae): estudo anatômico e ultraestrutural

Buarque, Plácido Fabrício Silva Melo [UNESP] 22 February 2013 (has links) (PDF)
Made available in DSpace on 2014-08-13T14:50:43Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-02-22Bitstream added on 2014-08-13T18:00:51Z : No. of bitstreams: 1 000753061.pdf: 8521142 bytes, checksum: 8ff08b1a5cc96e7c53fdfd57bedb8220 (MD5) / Espaços secretores estão distribuídos por todo o eixo vegetativo de Copaifera langsdorffii. São constituídos por epitélio secretor unisseriado e lúmen amplo e, devido à secreção produzida, representam um mecanismo de defesa constitutivo contra herbívoros e patógenos. Nas plântulas desta espécie, cavidades secretoras de óleo ocorrem no mesofilo dos eofilos e no córtex do epicótilo e hipocótilo, enquanto que canais secretores de oleorresina estão presentes na medula do epicótilo e hipocótilo. Evidências sugerem que fatores exógenos podem influenciar na produção da secreção nessa espécie; entretanto, nada se conhece sobre a influência desses fatores no desenvolvimento de canais e cavidades. Este trabalho teve como objetivo investigar a influência da luz e da temperatura na densidade e na área do lúmen de cavidades e canais secretores em plântulas de C. langsdorffii, além de estudar a influência da temperatura na ultraestrutura das células epiteliais. Plântulas foram mantidas em câmara climática sob 2500lux, 1250lux e 250lux e 15ºC, 25ºC e 35ºC. Para análises anatômicas quantitativas, amostras do epicótilo e eofilos foram processadas segundo técnicas usuais em anatomia vegetal. Para análises ultraestruturais, amostras de eofilos foram preparadas de acordo com técnicas convencionais de microscopia eletrônica de transmissão. Plântulas mantidas sob 25ºC/1250lux mostraram maior densidade de cavidades nos eofilos e no epicótilo, enquanto aquelas mantidas sob 25ºC/2500lux apresentaram maior densidade de ... / Secretory spaces are distributed throughout the vegetative axis of Copaifera langsdorffii. They are constituted by uniseriate secretory epithelium and wide lumen, and represent a constitutive defense mechanism against herbivores and pathogens due to the produced secretion. In C. langsdorffii seedlings, oil cavities occur in the mesophyll of eophylls and in the cortex of epicotyl and hypocotyl, whereas oleoresin canals are present in the pith of epicotyl and hypocotyl. Evidences suggest that exogenous factors can influence the production of secretion in this species; however, nothing is known about these factors influencing the development of canals and cavities. This work aimed to investigate the influence of light and temperature on the density and lumen area of secretory canals and cavities in seedlings of C. langsdorffii, besides to study the influence of the temperature on the ultrastructural features of epithelial cells. Seedlings were maintained in climatic chamber under 2500lux, 1250lux and 250lux, and 15ºC, 25ºC and 35ºC. For quantitative anatomical analysis, samples of epicotyl and eophylls were processed according to usual techniques in plant anatomy. For ultrastructural studies, samples of eophylls were prepared following conventional techniques of transmission electron microscopy. Seedlings under 25ºC/1250lux presented higher density of cavities in eophylls and epicotyl, whereas seedlings under 25ºC/2500lux showed higher density of canals. This differential answer to light can be related to the distinctive origin of these secretory structures. Concerning the lumen area, variable answers were observed to cavities and canals. Ultrastructurally, epithelial cells of seedlings under 25ºC showed evidences of intense secretory activity. Alterations in mitochondria, plastids and endoplasmic reticulum were observed in seedlings under 15ºC and 35ºC. In seedlings under 35ºC, the epithelial cells showed evident signals of lysis, ...
39

Crescimento e desenvolvimento de Plinia cauliflora de acordo com a intensidade luminosa em clima subtropical / Growth and development of Plinia cauliflora according to light intensity in subtropical condition

Dotto, Marcelo 17 December 2015 (has links)
As jabuticabeiras são pertencentes da família Myrtaceae e ao gênero Plinia. Existem cerca de nove espécies desta fruteira, das quais se destacam Plinia trunciflora (jabuticaba de cabinho) que tem ocorrência natural na região Sudoeste do Paraná, P. cauliflora (jabuticaba paulista ou jabuticaba Açu) e P. jaboticaba (Vell) (jabuticaba sabará), sendo que ambas produzem frutos tanto para a indústria como para consumo in natura. Apesar disso, não existem muitos pomares comercias com a cultura, prevalecendo-se o extrativismo. Isto pode estar aliado a falta de conhecimento técnico para o manejo das plantas a campo. Como tais espécies são encontradas na mata, o primeiro ponto é se estas podem se adaptar a outras condições de luminosidade. Este trabalho teve como objetivo identificar o comportamento adaptativo da jabuticabeira muda e planta quando expostas ao ambiente com diferentes intensidades luminosas e qual desta é considerada como ideal para o crescimento, bem como, a influência deste comportamento na produção de compostos secundários nas folhas das plantas. Para tanto, foram realizados dois experimentos, sendo o primeiro envolvido com o estudo das mudas e o segundo com plantas a campo. O trabalho foi realizado na Universidade Tecnológica Federal do Paraná – Câmpus Dois Vizinhos – Paraná. O delineamento experimental foi em delineamento inteiramente casualizado e em blocos ao acaso, com cinco tratamentos e 4 repetições de 10 mudas ou 2 plantas por unidade experimental, segundo condição de viveiro e pomar, respectivamente. Os tratamentos foram baseados de acordo com a intensidade luminosa, sendo estes, tratamento 1 - pleno sol, representando condição de pomar, com 0% de sombreamento artificial; tratamento 2 - cobertura lateral com tela de sombreamento e superior com plástico transparente, representando condição de clareira, tratamento 3 - cobertura lateral e superior com tela de sombreamento, representando estádio em que o dossel da mata esteja se fechando, incidindo apenas irradiação solar indireta; tratamento 4 - cobertura lateral e superior com tela de sombreamento, simulando condição de dossel fechado; com DFF (Densidade de fluxo de fótons) de 10% (90% de sombreamento); tratamento 5 - cobertura lateral e superior com tela de sombreamento, simulando condição de dossel mais aberto, com DFF de 65% (35% de sombreamento). Foram analisados, mensalmente variáveis ligadas as características de crescimento e desenvolvimento das plantas, bem como, parte do período com características bioquímicas das folhas ligadas aos metabólitos secundários, da atividade microbiológica do solo e nas mudas das massas de matéria fresca e seca da raiz e parte aérea e do comprimento radicular. Para o crescimento e desenvolvimento de mudas de jabuticabeira Açú Paulista pode-se utilizar tela de sombreamento lateral com 80% de sombra e cobertura com filme agrícola de 150 micras bem como tela de sombreamento com 50%. Para o crescimento e desenvolvimento de plantas de jabuticabeira Híbrida recomenda-se o uso de tela de sombreamento de qualquer malha sobre a planta. Para produção de extratos a partir de metabólitos secundários produzidos pela planta, deve-se mantê-las em condição de cultivo a pleno sol. / The jabuticaba fruit tree from classified in the Myrtaceae family and Plinia genre. There are about nine species of this fruit tree, that include as most important, Plinia trunciflora (jabuticaba de cabinho), naturally occurring in southwestern Paraná State, Brazil, P. cauliflora (jabuticaba Paulista or Jabuticaba Açu) and P. jaboticaba (Vell) (jabuticaba sabará), with all the over species producing fruit for the industry or fresh consumption. Nevertheless, there aren‟t commercial orchards with this culture, with highest yield part from extractive. This fact can be combined with lack of technical knowledge for the plants produce in the field. As these species are found in the forest, the first point is whether they can adapt to other light intensity conditions. The aim of this work was to identify the adaptive behavior of jabuticaba fruit seedling and tree when they were put in different light intensities and what this can be considered ideal for the growth, as well as, its influence in the leaves secondary compounds production. Two experiments were conducted, with the first involved with the study of the seedlings and the second with plants in the field. The work was carried out at Universidade Tecnológica Federal do Paraná – Câmpus Dois Vizinhos, Paraná State - Brazil. The experimental design was a completely randomized and a block design with four treatments and four replications of 10 seedlings or two plants per plot, according to nursery or orchard conditions, respectively. The treatments were base according to the light intensity. The treatments used were, 1 - full sun, similar the orchard condition, with 0% shading; 2 - side cover with shade cloth and top with transparent plastic, representing a gap forest condition; 3 - side and top cover with shade cloth, representing stage where the forest canopy is closing, focusing only indirect sunlight; 4 - side and top cover with shade cloth, simulating a closed canopy condition, with PPD (photon flux density) of 10% (90% shading); 5 - side and top cover with shade cloth, simulating a more open canopy condition with PPD 65% (35% shading). The growth and development seedling and plant characteristics were evaluated once by month, as also, during time part in the plants the secondary metabolites leaves, soil activity microbiological and the fresh and dry matter root and shoot and, root length from seedlings. For the growth and development of jabuticaba Açú Paulista seedling recommend to use of side cover with shade cloth and top with transparent plastic, representing a gap forest condition. In orchard, for the growth and development of plants jabuticaba Híbrida tree it was recommended the use of side and top cover with shade cloth of some type. For production of secondary metabolites of leaves, the plant must to be full sunlight condition orchard.
40

Caracterização físico-química, biocompostos e minerais de Ananas ananassoides cultivados em diferentes condições de luminosidade. /

Ota, Karen Cristina Gimenis Gil. January 2018 (has links)
Orientador: Ivanise Guilherme Branco / Banca: Cassia Roberta Malacrida Mayer / Banca: Bruno Henrique de Oliveira / Resumo: Os frutos do cerrado são atualmente estudados por apresentarem em sua composição substâncias com funções protetoras e preventivas de processos nocivos à saúde, além de fornecerem nutrientes essenciais ao adequado funcionamento do organismo. Dentre estes frutos está o Ananas ananassoides, planta da família Bromeliaceae, endêmica do Cerrado Brasileiro, popularmente conhecida como ananás, ananaí, ananás-de-raposa ou também abacaxizinho do cerrado. Seus frutos são resistentes à ação da natureza, além de pequenos e fibrosos. Apresentam elevado teor de açúcar, acidez e pequenas sementes. Estudos mostram que os frutos do cerrado apresentam boa capacidade antioxidante, porém investigações científicas que envolvem a caracterização físico-química, compostos bioativos, quantificação mineral e o efeito da incidência solar nos frutos de A. ananassoides não foram totalmente elucidados. Como a caracterização e uso deste fruto é pouco explorado o objetivo deste trabalho foi avaliar os compostos bioativos (carotenoides, compostos fenólicos, vitamina C e capacidade antioxidante), bem como as características físico-químicas e minerais do fruto em condições de luminosidade e sombreamento / Abstract: The fruits of the cerrado are currently studied because they present substances in its composition with protective and preventive functions against harmful processes to health, besides they provide essential nutrients to the appropriate organism functioning. Among this fruits is the Ananas ananassoides, plant of Bromeliaceae family, endemic of the brazilian cerrado, popularly known as ananás, ananaí, ananás-de-raposa or also abacaxizinho-do-cerrado. Its fruits are little and fibrous besides being resistant to the action of nature, They present high sugar content, acidity and small seeds. Studies show that the fruits of the cerrado present good antioxidant capacity, however scientific investigations that involve the physical-chemical caracterization, bioactive compounds, mineral quantification and the effect of solar incidence in fruits of A. ananassoides were not totally elucidated. As the caracterization and use of this fruit is poorly explored, the objective of this study was to avaliate the bioactive compounds (carotenoids, phenolic compounds, vitamin C and antioxidant capacity), as well as the physical-chemical and mineral characteristics of the fruit in conditions of luminosity and darkness / Mestre

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