O Pinus elliotti representa o principal produtor atual de exploração de resina no setor florestal brasileiro. Recentemente, plantios de P. elliottii X P. caribaea vêm se destacando, principalmente, pela sua maior produtividade em biomassa. Além disto, a resina do híbrido apresenta características químicas semelhantes aos seus parentais. Porém, poucas são as informações quanto a estaquia de espécies do gênero Pinus, e se focarmos na propagação de árvores adultas, tal carência é ainda maior, principalmente ao se considerar a dificuldade de rejuvenescimento/revigoramento do material genético. Neste contexto, o presente trabalho teve como objetivo geral avaliar o enraizamento adventício do P. elliottii var. elliottii e P. elliottii X P. caribaea adultos. Para tanto, o trabalho foi dividido em três diferentes estudos. O primeiro (Capítulo 2) avaliou o enraizamento adventício de estacas das matrizes adultas de P. elliottii e P. elliottii X P. caribaea no 5° estágio de enxertia seriada com e sem podas sucessivas, sob ação do AIB, talco com fungicida Cerconil® e terebentina. O segundo (Capítulo 3) foi baseado na avaliação do enraizamento adventício de estacas no 2° estágio de enxertia seriada de uma matriz adulta de P. elliottii var. elliottii submetida a um ano de podas sucessivas, sob ação do AIB, terebentina e paclobutrazol. Por sua vez, o terceiro estudo (Capítulo 4) consistiu na avaliação do enraizamento adventício de braquiblastos e brotos de duas matrizes adulta de P. elliottii e P. elliottii X Pinus caribaea, sob ação do AIB e paclobutrazol. Os resultados permitiram inferir que a sobrevivência e o enraizamento adventício aos diferentes tratamentos variaram de acordo com o genótipo e com as características morfológicas das estacas (grau de lignificação e tipo de estacas, brotos e braquiblastos). De maneira geral, os resultados evidenciaram a atuação das enxertias seriadas e das podas sucessivas na restauração da competência rizogênica das estacas dos brotos das matrizes adultas de P. elliottii e P. elliottii X P. caribaea, promovido pelo rejuvenescimento/ revigoramento parcial das matrizes. Além disto, a estaquia de braquiblastos mostrou ser uma ferramenta promissora para a propagação de espécies do gênero Pinus. / Pinus elliottii is the main current resin extraction producer in the Brazilian forest sector. Recently, plantations of P. elliottii X P. caribaea play a great importance in the production systems mainly by its high biomass productivity. In addition, the hybrid resin has chemical characteristics similar to their parents. However, there is little information on obtaining clones, and considering the propagation of mature trees, this lack of information is even greater, mainly concerning the difficulty to achieve the rejuvenation/ reinvigoration of the genetic material. Based on theses information, the present work was aimed to evaluate the adventitious rooting of mature P. elliottii var. elliottii and P. elliottii X P. caribaea cuttings. Therefore, the work was divided into three basic studies. The first study (Chapter 2) was based on the evaluation of adventitious rooting of mature P. elliottii and P. elliottii X caribaea cuttings of grafts up five sequential grafting with and without pruning, under the action of AIB, talc with fungicide and turpentine. The second (Chapter 3) was based on the evaluation of adventitious rooting of mature P. elliottii cuttings of grafts up two sequential grafting with pruning, under the action of IBA, paclobutrazol and turpentine. The third (Chapter 4) evaluated the adventitious rooting of brachyblast and shoots of mature P. elliottii and P. elliottii X caribaea cuttings, under the action of IBA and paclobutrazol. Results showed that the cutting survival and root growth, under the action of different treatments, varied according to the genotype and morphological characteristics of the material (cutting lignifications and type, brachyblast or shoot). Overall, our results showed the performance of serial grafting and pruning on the restoration of rooting competence in P. elliottii and P. elliottii X P. caribaea stem cuttings, promoted by the rejuvenation of trees. Moreover, the cutting of brachyblast can be a promising tool for the propagation of Pinus species.

O uso de inseticidas em um agroecossistema pode interferir na densidade e ação dos inimigos naturais e comprometer a eficácia do controle biológico dentro de um programa de manejo integrado de pragas. Dessa forma, objetivou-se avaliar, em laboratório, os efeitos letal e subletais de inseticidas reguladores de crescimento sobre larvas e adultos com até 24 h de idade do predador Ceraeochrysa cubana (Hagen, 1861). Para isso, larvas recém-eclodidas foram submetidas à pulverização de 2 mL de calda, do respectivo tratamento, em torre de Potter ajustada para deposição de 1,8 ± 0,1 mg cm-2. Os inseticidas e doses (g i.a. L-1) avaliados foram: piriproxifem 0,2 (Tiger 100 EC), buprofezina 0,5 (Applaud 250), tebufenozida 0,22 (Mimic 240 SC), metoxifenozida 0,75 (Intrepid 240 SC), diflubenzurom 0,12 (Micromite 240 SC), lufenurom 0,05 (Match EC). Água destilada foi utilizada como tratamento controle. A mortalidade de larvas, pupas e adultos e o número de ovos depositados pelas fêmeas foram avaliados a cada 24 h. A viabilidade de ovos foi determinada a partir da terceira oviposição das fêmeas utilizando 100 ovos de cada indivíduo. Os efeitos letais foram observados em larvas tratadas com diflubenzurom, lufenurom e piriproxifem. Os inseticidas piriproxifem, tebufenozida, metoxifenozida e buprofezina causaram redução na fecundidade de 20 a 40% e na fertilidade de no máximo 10%, sendo considerados levemente nocivos (30<E<=79 de redução), enquanto que, diflubenzurom e lufenurom causaram 100% de mortalidade de larvas de C. cubana e foram considerados nocivos ao predador (E>99%). Não houve diferenças significativas entre os tratamentos quanto aos parâmetros taxa líquida de reprodução (Ro), taxa intrínseca de crescimento (rm) e taxa finita de aumento (?). No entanto, diferenças significativas foram constatadas no tempo médio entre gerações (T), sendo que os menores valores foram constatados nos insetos expostos aos inseticidas tebufenozida e metoxifenozida. No bioensaio com adultos, lufenurom, diflubenzurom reduziram significativamente a fecundidade e fertilidade, enquanto que, tebufenozida, metoxifenozida e buprofezina não diferiram do controle. Piriproxifem reduziu significativamente a fecundidade total, porém, não afetou a fertilidade e a longevidade. Embora inseticidas reguladores de crescimento sejam comumente considerados como seletivos, afetaram a sobrevivência e reprodução de C. cubana em condições de laboratório. Todos os inseticidas testados devem ser submetidos a ensaios de semi-campo o para confirmação dos resultados, entretanto, tebufenozida, metoxifenozida, buprofezina e piriproxifem foram considerados levemente nocivos e, consequentemente, mais indicados para utilização dentro de programas de manejo integrado de pragas envolvendo C. cubana ou outras espécies de crisopídeos. / The use of pesticides within an agricultural system can interfere with the density and functionality of natural enemies, thus endangering the efficacy of biological control in the Integrated Pest Management program. Hence, this study evaluated the lethal and sublethal effects of six Insect Growth Regulators (IGR) insecticides over the larvae and adults of Green Lacewing Ceraeochrysa cubana (Hagen, 1861) under laboratory conditions. Neonate larvae and newly-emerged adults were sprayed with the respective treatments with the aid of a Potter Tower (2 mL of spray solution, 1.8 ± 0.1 mg cm-2 of deposition). The insecticides and rates (g a.i. L-1) evaluated were: pyriproxyfen 0.2 (Tiger 100 EC), buprofezin 0.5 (Applaud 250), tebufenozide 0.22 (Mimic 240 SC), methoxyfenozide 0.75 (Intrepid 240 SC), diflubenzuron 0.12 (Micromite 240 SC), lufenuron 0.05 (Match EC) and for control, distilled water. The mortality of larvae, pupa and adults and the number of eggs laid were registered daily. The viability was assessed by observing the percentage of eclosion from 100 eggs. Lethal effects were observed in larvae treated with diflubenzurom, lufenuron and pyriproxyfen. The insecticides pyriproxyfen, tebufenozide, methoxyfenozide and buprofezin reduced fecundity from 20 to 40% and fertility at highest 10%, being considered slightly harmful (30%<E<79%), whereas diflubenzuron and lufenuron caused 100% of larvae mortality and were considered harmful (E>99%). No significant differences were found among treatments for net reproduction rate (Ro), intrinsic growth rate (rm) and finite rate of increase (?). However, significant differences were found in mean generation time (T) for methoxyfenozide and tebufenozide. For adult bioassay, lufenuron and diflubenzuron reduced significantly the fecundity and fertility, whereas tebufenozide, methoxyfenozide and buprofezin did not differ from control. Pyriproxyfen significantly reduced the fecundity, but, did not affect fertility and longevity. Although IGRs are commonly taken as selective insecticides, they reduced the survivorship and reproduction of C. cubana in laboratory conditions. All products must be directed for semi-field studies for confirmation of results, however, tebufenozide, methoxyfenozide and buprofezin were considered slightly harmful for larvae and, consequently more appropriate to use in Integrated Pest Management programs whenever C. cubana as well as other lacewing species are present.

Master of Technology: Horticulture in the Faculty of Applied Sciences at the Cape Peninsula University of Technology, 2011 / A study was conducted to investigate the effects of: i) various media compositions and wounding treatments on the in vitro germination, growth and regeneration of Strelitzia reginae plantlets derived from zygotic embryos, ii) antioxidants, plant growth regulator (PGR) concentrations and plant tissue wounding treatments on phenolic compound production. One experiment consisted of 8 medium types including different combinations of Murashige and Skoog (MS) medium strength, activated charcoal and vitamin supplements. Twelve replicates were used for each treatment. In another experiment, germinated plantlets were subjected to 2 wounding treatments; (unwounded explants (control) and explants longitudinally sectioned through the apical meristem). The explants were transferred to ten different regeneration media consiting of different concentrations and combinations of auxin and cytokinin supplements and antioxidants. Ten replicates were used for each treatment. Results indicated the positive role of activated charcoal (AC) in reducing oxidative browning of embryo explants. The highest germination rate of embryos was observed in media containing AC without vitamin supplementation. Germination significantly decreased with the addition of vitamins. With regard to effects of various media compositions and wounding treatments on in vitro growth and regeneration of Strelitzia, significant results were achieved with 1-naphthalene acetic acid (NAA) and 6-benzylaminopurine (BAP) concentrations on explant discoloration and callus formation. The antioxidant treatments, activated charcoal (AC) and ascorbic acid (AA) significantly affected explant discoloration, the induction of callus and the length of roots developed. Wounding treatments affected plant height, increased explant height and callus formation. Interactions between higher NAA and BAP concentrations together with wounding resulted in the most effective treatment in reducing explant discoloration at the media contact point. Furthermore, results showed the various NAA and BAP concentrations to significantly affect phenolic exudation. The media containing the highest PGR concentration resulted in the highest phenol content. AC significantly reduced the total phenol content of media by 53%, compared with AA. Phenolic exudation was significantly increased as a result of explant wounding. Various interactions between the NAA and BAP concentrations, antioxidants and wounding affected phenolic exudation and the total phenol content of media. This study provides insight into the contributing factors and methods of overcoming the major problem of phenolic oxidation and promoting the in vitro growth and regeneration of Strelitzia.

O presente trabalho teve por objetivo avaliar a atuação de biorreguladores (ANA, BAP, TDZ e 2iP) no desenvolvimento morfogenético de microplantas de pupunheiras. Para tanto, a cada 28 dias aferiram-se o número de propágulos, o desenvolvimento radicular, o comprimento e a taxa de crescimento da parte aérea, número de folhas, oxidação, número de centros meristemáticos na região basal dos explantes e nas bainhas e/ou nos primórdios foliares dos propágulos, número de complexos celulares pró-embriogênicos e as rotas e padrões morfogênicos. Todos os experimentos foram conduzidos em delineamento inteiramente casualizado. Os dados qualitativos foram apresentados como porcentagens e médias gerais e os dados quantitativos foram submetidos à análise de regressão polinomial ou exponencial. As avaliações morfofisiológicas evidenciaram que o TDZ isoladamente favoreceu o desenvolvimento de gemas adventícias, embora curtas e por vezes, com acúleos. Embriões somáticos somente não se desenvolveram em tratamentos contendo a presença isolada de BAP, TDZ e 2iP, nos demais tratamentos observou-se um comportamento exponencial, cujo número foi reduzido e variou apenas em função do período de cultivo. Maior número de raízes foi observado no tratamento contendo ANA em associação ao BAP, embora o tratamento controle tenha induzido maior porcentagem de explantes enraizados e com maior comprimento, sendo o único a evidenciar ramificação. A presença isolada do TDZ promoveu maior comprimento da parte aérea e sua associação ao ANA promoveu a maior taxa de crescimento. O melhor desenvolvimento da parte aérea de microplantas e explantes de pupunheiras ocorreu em meio de cultura MS isento de biorreguladores ou em meio constituído pela associação entre ANA/TDZ aos 140 dias de cultivo, sendo que o acréscimo isolado das citocininas BAP, TDZ e 2iP no meio de cultura MS promoveu tardiamente a taxa máxima de crescimento. A adição isolada do 2iP no meio de cultura promoveu intensa oxidação nas primeiras folhas desenvolvidas das microplantas em explantes de pupunheiras e a aplicação isolada do TDZ ou associada à ANA promoveu anomalias como dobramento foliar e desenvolvimento de acúleos. O monitoramento das rotas e padrões morfogênicos evidenciou que embriões somáticos com origem multicelular originaramse diretamente na região central da base dos explantes nos tratamentos isentos de biorreguladores, na presença isolada de ANA e de TDZ ou na associação de ambos. Pró-embriões com origem unicelular foram induzidos também na presença isolada de ANA ou TDZ e nas associações ANA/BAP ou ANA/TDZ, sendo que pró-embriões com origem multicelular foram induzidos na presença isolada do TDZ a partir da atividade meristemática apical caulinar e a partir da (bi) polarização de elevado número de centros meristemáticos presentes na extremidade distal da base destes explantes. Gemas adventícias com origem multicelular diretamente da extremidade proximal da base dos explantes foram induzidas em maior freqüência no tratamento isento de biorreguladores e no tratamento contendo ANA/TDZ. Entre os primórdios foliares dos explantes, estas estruturas foram freqüentemente induzidas em tratamentos contendo a presença isolada de ANA. / This study aimed to evaluate the role of bioregulators (NAA, BAP, TDZ and 2iP) on the morphogenetic development of pejibaye microplants. For this, every 28 days, the number of propagules, the root development, the length and the growth rate of shoots, the number of leaves, the oxidation, the number of meristematic centers in the explants basal region and in the leaf sheaths and/or in the propagules leaf primordia, the number of pro-embryogenic cell complex and the morphogenic routes and patterns were measured. All experiments were conducted in a randomized design. Qualitative data were presented as percentages and general averages, and quantitative data were subjected to polynomial regression or exponential analysis. The morphophysiological evaluations showed that the TDZ alone favored the development of adventitious buds, although short, and sometimes with thorns. Only in the treatments with the isolated presence of BAP, TDZ and 2iP, somatic embryos were not developed. For the other treatments there was an exponential behavior, in which the number of somatic embryos was reduced and varied according only to the cultivation period. Although a greater number of roots was observed in the treatment, in which NAA was associated with BAP, the control treatment has induced the highest rate of rooted explants and with greater root length, and has been the single one that produced branches. The isolated presence of TDZ promoted the greater shoot length, and its association with ANA promoted the highest growth rate. The best shoot development of pejibaye microplants and explants occurred in the MS bioregulator-free culture medium of or in the medium with NAA/TDZ association, at140 days of cultivation. Moreover, the isolated addition of the cytokinins BAP, TDZ and 2iP in the medium, later promoted the highest growth rate. In pejibaye explants the addition of 2iP alone promoted intense oxidation of the first developed leaves and the application of TDZ alone or associated with ANA promoted anomalies such as folding leaf and thorn development. The monitoring of the morphogenetic routes and patterns showed that in the treatments that were bioregulator-free, or with the isolated presence of NAA and TDZ, or the association of both, somatic embryos, from multicellular origin, raised up directly in the central region of the explants base. Pro-embryos from unicellular origin were also induced in the isolated presence of NAA or in NAA/BAP and NAA/TDZ associations. Moreover, in the isolated presence of TDZ, pro-embryos from multicellular origin were induced from shoot apical meristem activity and from the (bi) polarization of a large number of meristematic centers in the distal extremity of the explants base. Adventitious buds with multicellular origin from the proximal extremity of the explants base were induced more frequently in the bioregulator-free treatment and in the treatment with NAA/TDZ. Between the leaf explants primordia, adventitious buds were often induced by the treatments with the isolated presence of ANA.

Finally, the PSRR performance of LDO is studied. An energy-efficient embedded ripple feed-forward path is proposed to improve the PSRR of LDO. Comparing with some state-of-the-art techniques for PSRR improvement, the proposed LDO features very simple structure thus low-power consumption. A LDO implemented in 0.18-mum CMOS technology with 0.042-mm2 active area has been designed to verify the idea. With an external 4.7-muF output capacitor, in the maximum load condition (i.e. at 25 mA), the PSRR is -77 dB at 1 MHz, -85 dB at 2.5 MHz and -55 dB at 5 MHz, respectively. The quiescent current is 15 muA only, while the transient voltage overshoot or undershoot is less than 40 mV when load current changes between 1 mA and 25 mA with 40-ns step time. The LDO achieves good line and load regulations of 3 mV/V and 50 muV/mA, respectively. / Remotely- or battery-powered wireless system-on-a-chip (SoC) needs energy-efficient and high-integration power-management solutions due to their energy-aware characteristics. Low-dropout regulator (LDO) is a good solution because of its excellent performances such as low power consumption, fast load-transient response and high power-supply ripple rejection (PSRR). Moreover, it is easy to be fully integrated since no inductor is needed to be the energy-storage element. Recent development of output-capacitorless LDO (OCL-LDO) realizes on-chip, local voltage regulation to enable more effective integrated power management for SoC. In this thesis, OCL-LDOs with low power consumption and fast load-transient response are investigated and presented in this thesis. LDO with output capacitor for high-PSRR operation to provide clean power supply to RF circuits is also reported. Three LDOs are developed and fabricated to verify the proposed ideas. / The first design is an ultra low-power voltage regulator for remotely powered energy-autonomous devices. It has been fabricated in a commercial 0.18-mum CMOS technology and applied to a passive UHF RFID tag IC. With the low-power voltage reference circuit and sub-threshold operations, the total quiescent current is 700 nA under a 1.8-V power supply. The output voltage of the regulator is 1.45 V with load capability of 50 muA. The temperature coefficients of the voltage reference and the output voltage are only 9 and 43 ppm/&deg;C, respectively. A POR signal with 150-ns-width pulse is also generated to reset the digital processing part in the tag IC. / The second design is a fast-transient OCL-LDO, which has been implemented in a commercial 90-nm CMOS technology. Experimental result verifies that it is stable for a capacitive load from 0 to 50 pF and with load capability of 100 rnA. Moreover, the gain-enhanced structure provides sufficient loop gain to improve line regulation to 3.78 mV/V and load regulation to 0.1 mV/mA, respectively. The embedded voltage-spike detection circuit enables pseudo Class-AB operation to drive the power transistor promptly. The maximum overshoot and undershoot under a 1.2-V supply are less than 66 mV for full load current changes within 100-ns edge time, and the recovery time is less than 5 mus. While the measured power consumption is only 6 muW under a 0.75-V supply. / Guo, Jianping. / Adviser: Ka Nang Leung. / Source: Dissertation Abstracts International, Volume: 73-06, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

Ho, Marco. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

電源管理集成電路被廣泛應用於便攜式電子應用。在同一芯片需要不同的電源電壓水平。由於芯片尺寸，工作速度和所需功耗的要求，低壓差穩壓器（LDO）在快遞瞬態響應，低噪聲，以及高精度的電子產品中具有廣泛的應用。 / LDO的負載瞬間變化取決於功率金氧半場效電晶體的大小、偏置電流和誤差放大器的增益。檢測輸出電壓，並使用大電容和電阻通過電容耦合，增加偏置電流是一個簡單的方法來改善負載瞬間變化。然而，電阻電容佔據較大的芯片面積。 / 權衡功耗和芯片尺寸，本論文中提出用數字檢測電路取代用於瞬態耦合的大電容和電阻。所提出的電路是讓功率金氧半場效電晶體的栅極電容電流增加充電或放電，以提高LDO的負載瞬間響應速度。產生這種電流通過檢測內部的變化，並產生一個電壓脈衝控制迴轉電流，然後通過使用一組數字電路去改變充電或放電的電量。 / 擬議的設計已在UMC0.18微米 CMOS制程技術實現。LDO的輸入電壓為0.9伏至1.3伏和穩壓0.7伏。最大輸出電流為50豪安。經過測量，負載瞬間變化得到改善。負載瞬間的響應時間可以從75微秒（傳統）減少到75納秒。 / Power-management IC is widely used in portable electronic applications. Different supply voltage levels are required in the same chip. Due to the size, speed and power requirements, low-dropout regulator (LDO) is generally adopted for applications which need fast transient response, low noise and high accuracy. / Transient response of a LDO is limited by the size of power MOSFET, biasing current and gain of error amplifier. Detecting the output voltage and using large RC components for capacitive coupling to increase the biasing current is a straightforward method to improve the transient response. However, this requires a large chip size for the RC components. / By considering power consumption and size, digital detection circuit is proposed to replace the large capacitors and resistors used for transient coupling. The proposed circuit is to increase the charging or discharging current to the gate of the power MOSFET to increase the transient speed of LDO. This current is generated by detecting the internal changes and generating a voltage pulse to control the slewing current by using a set of digital circuit. / The proposed design has been realized in UMC 0.18μm CMOS technology. The input voltage of the LDO is 0.9 to 1.3V and the regulated voltage is 0.7V. The maximum output current is 50mA. From the measurement, the transient response is improved. The response time due to load transient changes can be reduced from 75s (conventional) to 75ns. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Kwong, Ka Yee. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references. / Abstracts also in Chinese. / Abstract / Acknowledgments / Table of Content / List of Figures / List of Tables / Chapter Chapter 1 --- LDO regulator research background / Introduction / Chapter Section 1.1 --- Generic LDO regulator structure / Chapter Section 1.2 --- Principle of LDO regulator operation / Chapter Section 1.3 --- Specifications / Chapter References / Chapter Chapter 2 --- Review of state-of-the-art transient-improvement techniques for LDO regulators / Introduction / Chapter Section 2.1 --- Slew rate improvement at power transistor gate / Chapter Section 2.2 --- Frequency compensation / Chapter Section 2.3 --- Short summary / References / Chapter Chapter 3 --- A proposed output-capacitorless LDO regulator with digital voltage spike detection / Chapter Introduction / Chapter Section 3.1 --- LDO regulator core structure / Chapter Section 3.2 --- Digital switches based LDO regulator / Chapter Section 3.3 --- LDO regulator with proposed digital voltage spike detection circuit / Chapter Section 3.4 --- Simulation result / Chapter Section 3.5 --- Short summary / References / Chapter Chapter 4 --- Measurement results / Introduction / Chapter Chapter 5 --- Conclusion and Future Work

The increasing concerns launched by debates about climate changes added to the uncontrolled growth of world population have opened a market to natural inputs for a more sustainable agriculture. Taking those concerns together, it is very important to think in advance in terms of finding solutions to increase the food production, with improved quality and in a supposed changing environment. Natural substances such as seaweed biostimulants are coming up as inputs for crops yield and abiotic stress tolerance enhancement with increasing use in agriculture. In this scene, it is important to understand effects and mode of action of these substances on plant physiology to permit the development of consistent products and guarantee the delivery of solutions to growers that assist them in solving their needs. Therefore, this research was carried out aiming to understand the role of agrochemicals (classical plant growth regulators and seaweed biostimulants) on root development and hormonal relations of tomato \'Micro-Tom\' and Arabidopsis under water deficit conditions. Ascophyllum nodosum extracts (ANE) ability to stimulate endogenous hormonal responses in conditions of drought and osmotic stress was tested. We carried out experiments with two plant models: one is classically used in plant science studies and the other, a crop-like plant model whose scientific findings can be applied for several crops. We used tomato hormonal mutants and reporter lines grown in conditions of drought stress to study the effects of plant growth regulators and seaweed extracts on root growth and hormonal responses, respectively. Additionally, we tested in vitro the effects of these substances on root growth of Arabidopsis seedlings under osmotic stress conditions. The root development of tomato and Arabidopsis was negatively affected by the presence of water deficit caused by drought and osmotic stress, respectively. Gibberellins biosynthesis inhibitors only affected the root growth of gibberellin-deficient mutant (gib-3). Extracts of the same seaweed presented different effects on root growth of Arabidopsis seedlings and hormonal responsiveness in roots of tomato, possibly due to variability in their compositions. ANE A and B show opposite effects on root growth. ANE A promotes root growth, whereas ANE B shows inhibitory effects. These substances seem to have little influence on auxin responses in roots, however, they alter the balance between abscisic acid and ethylene under drought conditions. The standardization of the composition of seaweed extracts complemented with studies on their physiological and molecular effects in crops is crucial for the establishment of these agricultural inputs as one of the solutions for current and future requirements of food production. / As crescentes preocupações oriundas a partir dos atuais debates sobre mudanças climáticas somadas ao descontrolado crescimento da população mundial têm dado espaço para o uso de insumos agrícolas naturais, objetivando sustentabilidade na agricultura. Diante de tais preocupações, é importante pensar antecipadamente e encontrar maneiras de aumentar a produção e a qualidade de alimentos, em um ambiente de supostas mudanças climáticas. Substâncias naturais, como bioestimulantes à base de alga, estão ganhando relevância como melhoradores da produtividade e tolerância a estresses abióticos com crescentes usos na agricultura. Diante desse cenário, é importante compreender os efeitos e modos de ação dessas substâncias na fisiologia das plantas para permitir o desenvolvimento de produtos consistentes e garantir aos produtores soluções que atendam às suas necessidades. Portanto, este estudo foi realizado com o objetivo de entender o papel de agroquímicos (reguladores vegetais clássicos e biostimulantes à base da alga) sobre o desenvolvimento radicular e relações hormonais do tomateiro \'Micro-Tom\' e Arabidopsis sob condições de estresse hídrico. Foi testada a habilidade de extratos Ascophyllum nodosum (ANE) em estimular respostas hormonais em condições de seca e estresse osmótico. Foram realizados experimentos com duas plantas-modelo: Arabidopsis que é largamente utilizada em estudos científicos de plantas e o tomateiro \'Micro-Tom\', uma planta-modelo mais adequada para estudos aplicados à agricultura sob condições tropicais. Foram utilizados mutantes hormonais e linhas-repórter de tomate cultivadas em condições de seca para o estudo dos efeitos dos reguladores vegetias e extratos de alga no crescimento radicular e respostas hormonais, respectivamente. Além disso, foram testados in vitro os efeitos dessas substâncias no crescimento radicular de plântulas de Arabidopsis em condições de estresse osmótico. O desenvolvimento radicular do tomateiro e Arabidopsis foi negativamente afetado pela ocorrência do déficit hídrico causado por seca e estresse osmótico, respectivamente. Inibidores de giberelinas afetaram apenas o crescimento radicular do mutante com baixo nível endógeno giberelinas (gib-3). Extratos da mesma espécie de alga apresentaram diferentes efeitos no crescimento radicular de plântulas de Arabidopsis e resposta hormonal em raízes de tomateiro. ANE A e B aprensenta efeitos opostos no desenvolvimento de raízes. ANE A promove o crescimento radicular enquanto ANE A inibe. ANEs pouco influenciam as respostas auxínicas, contudo, essas substâncias alteram o balanço entre entre ácido abscísico e etileno sob condições de estresse hídrico por seca. A padronização da composição de extratos de alga somada aos estudos sobre os seus efeitos fisiológicos e moleculares em culturas é crucial para o estabelecimento desses insumos agrícolas como uma das soluções para as necessidades atuais e futuras da produção de alimentos.

Made available in DSpace on 2014-06-11T19:31:01Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-12-18Bitstream added on 2014-06-13T19:01:11Z : No. of bitstreams: 1 campos_mf_dr_botib.pdf: 592742 bytes, checksum: 69c6b5935172801d218019ca8900bfe7 (MD5) / Tratamentos com reguladores vegetais foram estudados em plantas de soja (Glycine max (L.) Merrill cv. BRS-184) para avaliar o teor de clorofila das folhas, a altura da planta, o número de ramificações e altura de vagens. O experimento foi conduzido em casa de vegetação do Departamento de Botânica do Instituto de Biociências de Botucatu - UNESP. O delineamento experimental utilizado foi inteiramente casualizado, com três repetições e oito tratamentos (testemunha; GA3 100 mg L-1; BAP 100 mg L-1; IBA 100 mg L-1; Stimulate® (IBA+GA3+Cinetina) 20 mL L-1; cloreto de mepiquat 100 mg L-1; cloreto de mepiquat 100 mg L-1+BAP 100 mg L-1+IBA 100 mg L-1 e ethephon 600 mg L-1. Os tratamentos foram aplicados três vezes, espaçados em 30 dias durante o ciclo da planta a partir do 43º dia e foram realizadas seis avaliações espaçados em 13 dias. Os tratamentos com BAP, ethephon e cloreto de mepiquat + IBA + BAP mantiveram o teor de clorofila nas folhas alto até o final do ciclo da planta. A altura de plantas foi menor que a testemunha em todos os tratamentos a partir de 90 dias após a semeadura, com exceção do tratamento com GA3, que manteve a altura de plantas superior durante todo ciclo da cultura. As ramificações das plantas foram incrementadas pelo tratamento com ethephon, que apresentou, a altura da primeira vagem inferior à testemunha. No tratamento com GA3, a altura da primeira vagem foi superior. / Treatments with plant growth regulators were studied in soybean plants (Glycine max (L.) Merrill cv. BRS-184) to assess the leaf chlorophyll content, the ramification number and the height of the pods. The experiment has been carried out at the greenhouse of the Botanic Department, Bioscience Institute, University of the Sao Paulo State – UNESP, campus of Rubiao Junior, Botucatu, Brazil. The used experimental design delineation was completely randomized block with three replications and eight treatments (control; GA3 100 mg L-1; BAP 100 mg L-1; IBA 100 mg L-1; Stimulate® (IBA+GA3+Cinetin) 20 mL L-1; mepiquat chloride 100 mg L-1; mepiquat chloride 100 mg L-1+BAP 100 mg L-1+IBA 100 mg L-1 and ethephon 600 mg L-1. The treatments were applied three times every 30 days during the plant cycle after 43 days and six evaluations have been made every 13 days. The treatments with BAP, ethephon and mepiquat chloride + IBA + BAP maintained the high chlorophyll content until the end of the plant cycle. The height of the plants was lower than the control in all treatments after the 90th day of sowing, excepting the treatment with GA3, which maintained the height of the plants during the cycle of cultivation. The plant stems were increased by the ethephon treatment; however, the height of the first pod was the lowest in this treatment and the highest in the treatment with GA3.

Made available in DSpace on 2017-07-10T17:37:41Z (GMT). No. of bitstreams: 1 Paulo_Barbosa_de_Oliveira_Filho.pdf: 1560316 bytes, checksum: 35cef49750a32c7ff5198fbb373e1dbb (MD5) Previous issue date: 2011-02-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The purpose of the present work was evaluate the effects of the control(without the application of maturators) and maturators glyphosate, paraquat, ethephon, KNO3, sulphometuron methyl, fluazifop-p-butyl and ethyl-trinexapac on the number of stems per area, diameter of the middle third of stem and productivity or tons of cane per hectare, and the brix, the pol cane and total recoverable sugar from sugarcane. The experimental design was randomized blocks with four replications in a split plot with four times the cutting portions 15, 30, 60 and 120 days after application (DAA) and subplots seven types of chemical maturators in their respective strengths per hectare glyphosate (0.4 L ha-¹), paraquat (2.0 L ha-¹), fluazifop-p-butyl (0.4 L ha-¹), ethephon (0.67 L ha-¹), etyl-trinexapac (1.0 L ha-¹), sulfometuron methyl (0.02 kg ha-¹) , KNO3 (3.0 kg ha-¹) and control (without the application of maturators). In all applications was used 0.1% v/v wetting agent etilenoxi-ethanol. The maturators were applied on the date of 22 May 10 in sugarcane ratoon 3rd cut with the aid of a knapsack sprayer with a metal tube with 1.20 m boom length and dual output each with a spray tip range ADIA type 11002 and spray 220 L ha-1 at constant rate. The KNO3 contributed to improving the productivity (TCH) by 43% compared to the control and the more favorable harvesting time to TCH was comprised of 60 to 120 days after application (DAA), compared to other times of harvest. The use of etyl-trinexapac, sulfometuron methyl and KNO3 resulted in an increase of 12, 13 and 14% for the variables ATR, Brix and PC, respectively, compared to the control at 120 days after application (DAA) of the maturators. In this way, the harvesting time most suitable for ratoon cane was at 120 days after application (DAA) of maturators and the control as provided in these conditions gains of 40, 32 and 42% for ATR, Brix and PC compared to their respective earliest epochs of reference (EER) EERatr, EERbrix and EERpc / O objetivo da realização deste experimento foi avaliar os efeitos da ação da testemunha (sem a aplicação de maturadores) e dos maturadores glifosato, paraquat, fluazifop-p-butil, ethephon, etyl-trinexapac, sulfometuron metil e KNO3 sobre o número de colmos por área, diâmetro do terço médio de colmos e produtividade ou toneladas de colmos por hectare, e o brix, pol da cana e açúcar total recuperável da cana-soca. O delineamento experimental utilizado foi em blocos casualizados, com quatro repetições, num esquema de parcelas subdivididas sendo as parcelas quatro épocas de colheita 15, 30, 60 e 120 dias após a aplicação (DAA) dos maturadores e as subparcelas sete tipos de maturadores químicos utilizando as suas dosagens comerciais recomendadas pelos respectivos fabricantes glifosato (0,4 L ha-1), paraquat (2,0 L ha-1), fluazifop-p-butil (0,4 L ha-1), ethephon (0,67 L ha-1), etyl-trinexapac (1,0 L ha-1), sulfometuron metil (0,02 kg ha-1) e KNO3 (3,0 kg ha-1), além de testemunha (sem a aplicação de maturadores). Em todas as aplicações foram utilizado 0,1% v/v de espalhante adesivo etilenoxi-etanol. Os maturadores foram aplicados na data de 22/05/10 em cana-soca de 3° corte com o auxílio de um pulverizador costal manual, com um tubo do tipo lança metálica com 1,20 m de comprimento e saída dupla, cada qual com uma ponta de pulverização do tipo ADIA leque 11002 e volume de calda de 220 L ha-1 em vazão constante. O KNO3 contribuiu para a melhoria da qualidade agronômica aumentando a produtividade de colmos (TCH) em 43% em relação à testemunha e a época de colheita mais favorável à variável ficou compreendida dos 60 aos 120 dias após a aplicação (DAA) do maturador, comparado às outras épocas de colheita. A aplicação de etyl-trinexapac, sulfometuron metil e KNO3 resultaram em aumento de 12, 13 e 14% para as variáveis ATR, Brix e PC, respectivamente, em comparação à testemunha e a melhor época de colheita foi aos 120 dias após a aplicação (DAA) destes maturadores. Desta forma, a época de colheita mais adequada para a cana-soca foi aos 120 dias após a aplicação (DAA) dos maturadores e testemunha, pois proporcionou, nestas condições ganhos de 40, 32 e 42% para ATR, Brix e PC em comparação às respectivas épocas iniciais de referência EIatr, EIbrix e EIPC