Orientador: João Domingos Rodrigues / Resumo: O tomateiro é uma das mais importantes culturas no Brasil, sendo São Paulo o segundo estado que mais produz este vegetal no país, atrás apenas de Goiás. Além do efeito protetor e curativo dos fungicidas utilizados para este estudo, verificou-se que também têm efeito sobre a fotossíntese líquida da planta, devido à redução momentânea da respiração celular, processo fisiológico que compete com a fotossíntese. Dado o exposto, este estudo teve como objetivo determinar o efeito fisiológico de fungicidas sobre a atividade de enzimas antioxidantes, a fotossíntese e as características produtivas e de viabilidade econômica do tomateiro 'saladete', híbrido Caribe F1 cultivado em casa de vegetação. O experimento foi conduzido na Fazenda de Ensino, Pesquisa e Produção de São Manuel-SP, pertencente à FCA/UNESP. Utilizou-se o delineamento experimental de blocos casualizados, com oito tratamentos e quatro repetições, cada unidade experimental contendo sete plantas. Os tratamentos referem-se ao uso de fungicidas com efeitos fisiológicos, nomeadamente: T1 – Controle; T2 – Piraclostrobina (CT); T3 – CT+BOS; T4 – Boscalida (BOS); T5 – BOS+FP; T6 – Fluxapiroxade+Piraclostrobina (FP); T7 – FP+CT e T8 – FP+CT+BOS. Foram realizados cinco testes de quantificação de trocas gasosas, realizando-se essas análises em diferentes momentos após a pulverização dos fungicidas. Como resultados foi possível observar que os fungicidas de efeitos fisiológicos aplicados nessa pesquisa influenciam positivamente nas... (Resumo completo, clicar acesso eletrônico abaixo) / Doutor

Orientador: Carmen Sílvia Fernandes Boaro / Resumo: Cálcio apresenta função estrutural, na parede celular, atua na manutenção da estabilidade da membrana plasmática e é mensageiro secundário, envolvido na regulação de processos fisiológicos do desenvolvimento e em respostas a estresses. No dano mecânico, espécies reativas de oxigênio (ERO) auxiliam no afrouxamento da parede celular e na abertura de canais de Ca2+ do reticulo endoplasmático e o aumento de Ca2+ no citoplasma gera uma cascata de sinais mediados por hormônios, ERO, peroxidases e cálcio-calmodulina. Além disso, o Ca2+ é de fundamental importância para o funcionamento do fotossistema II (PSII), uma vez que, sua variação pode interferir na cadeia transportadora de elétrons. O objetivo deste estudo foi investigar a influência da variação de cálcio na sinalização de defesa de plantas de crescimento lento e rápido e submetidas a dano mecânico. O delineamento experimental foi em blocos casualizados, com quatro repetições, em esquema fatorial, onde as plantas foram cultivadas com 0, 2 e 4 mM de Ca2+, com e sem dano mecânico e cinco épocas de avaliação, realizadas aos 0, 15, 30, 60 e 90 dias após o dano mecânico. Com a espécie de crescimento lento, Annona emarginata, foram estudados fotossíntese (fluorescência da clorofila a e trocas gasosas), massa seca total, crescimento quantitativo e peroxidação lipídica. No Solanum lycopersicum Micro-Tom, espécie de crescimento rápido, expressão de genes de estresses, enzimas antioxidantes, peroxido de hidrogênio, peroxidação lipídica... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Calcium presents structural function in the cell wall, it acts in the maintenance of the stability of the plasma membrane and is secondary messenger, involved in the regulation of physiological processes of development and in responses to stresses. In mechanical damage, reactive oxygen species (ROS) assist in the loosening of the cell wall and in the opening of Ca2+ channels of the endoplasmic reticulum, and the increase of Ca2+ in the cytoplasm generates a cascade of signals mediated by hormones, ROS, peroxidases and calcium-calmodulin. In addition, Ca2+ is of fundamental importance for the functioning of photosystem II (PSII), since its variation can interfere with the electron transport chain. The objective of this study was to investigate the influence of calcium variation on defense signaling of slow and fast growing plants and submitted to mechanical damage. The experimental design was a randomized block, with four replications in a factorial design, where the plants were cultured with 0, 2 and 4 mM Ca2+ with and without mechanical damage five evaluation times were made at 0, 15, 30, 60 and 90 days after mechanical damage. With the slow-growing species, Annona emarginata, photosynthesis (chlorophyll a fluorescence and gas exchange), total dry mass, quantitative growth and lipid peroxidation were studied. The results allowed to conclude that the Annona emarginata plants presented greater resistance to the mechanical damage in the presence of calcium and were more sensiti... (Complete abstract click electronic access below) / Doutor

Chlorophyll and solanine syntheses as influenced by cultivars, specific gravities, light intensities, and duration of exposure to light were studied in potato (Solanum tuberosum, L.) tubers. Chemicals, gamma radiation, clear polyethylene packaging in 15 per cent co 2 , and storage at subatmospheric pressure were employed to control the formation of these two compounds. The toxicity of solanine to mice, the fungus Trichoderma viride, and cholinesterase inhibition patterns in rabbits and a dog were evaluated. The influence of the central nervous system stimulating drugs was investigated to find if they counteracted solanine toxicity. Of the 11 cultivars tested, tubers of Bounty, Kennebec, Nor chip, and Red Lasoda were most sensitive to greening and solanine development. LaChipper and Platte tubers were least susceptible to greening and their solanine contents were minimum. The significant differences in chlorophyll and solanine formation among cultivars showed that greening potential is a cultivar characteristic. xi Chlorophyll development in tubers was inversely related to their specific gravity. Solanine synthesis was, however, not dependent on specific gravity. Studies on effect of four light intensities on Kennebec potato tubers that were stored for nearly 6 months showed that more chlorophyll formed at 100 and 150 ft-c than at 50 and 200 ft-c light intensities. Generally, chlorophyll formation increased with increased light intensity up to 100 ft-c, slowly and steadily declined up to 150 ft-c, and sharply declined at 200 ft-c. There were no significant differences in the solanine contents of the tubers after exposure to these light intensities. The duration of exposure of the tubers to 100 ft-c revealed that solanine and chlorophyll contents increased linearly with the duration of exposure up to the sixth and tenth day, respectively. There was no difference in the amount of chlorophyll formed at the end of the tenth and fifteenth day. The solanine contents were rather constant from the sixth to the tenth day and then slightly declined at the end of the fifteenth day. The respiration of the tubers did not seem to have an apparent relationship to solanine and chlorophyll formation. Investigation on the control of greening showed that two chemicals, Ethrel (2-chloroethylphosphonic acid) and Alar (succinamic acid, 2, 2-dimethylhydrazide) when applied at 10, 000 ppm by vacuum injection technique, were significantly effective in inhibiting chlorophyll and solanine syntheses. Ethrel was most effective in controlling the chlorophyll formation and the least solanine xii was formed after the Alar treatment. The dose of 10 krads of gamma radiation inhibited 80 per cent, while polyethylene packaging with 15 per cent co 2 , only 32 per cent of chlorophyll synthesis. Storage of tubers at subatmospheric pressure of 126 mm-Hg resulted in complete inhibition of chlorophyll formation. The irradiation, co 2 environment either alone or in combination, and subatmospheric pressure treatments did not affect solanine synthesis. Solanine was toxic to mice, rabbits, a dog, and the fungus Trichoderma viride. The LD 50 for intraperitoneal (ip) administration, single dose, in mice was 32. 3 mg of solanine per Kg body weight, the 19/20 confidence limits being 27. 6 - 37. 9 mg. Plasma and erythrocytic cholinesterase inhibition in rabbits indicated that solanine was a weak to moderate inhibitor of both specific and nonspecific cholinesterase. There was less inhibition of erythrocytic cholinesterase than that of plasma in vivo. In an anesthetized dog, cumulative doses of solanine showed a quick inhibition of cholinesterase but rapid recovery · was noted in the case of serum enzyme, while there was no inhibition of the red cell enzyme. A prior intraperitoneal dose of 2 mg/Kg of atropine sulfate lowered the mortality after ip injection into mice at 40 mg/Kg of solanine from 9/10 to 5/10. Similar application of pargyline (5 mg/Kg ip) and amphetamine (5 mg/Kg ip) had no effect on mortality from solanine. Atropine influence appeared antagonistic and counteracted solanine toxicity. The concentration of 10 mg of solanine per 100 ml of potato-dextroseagar medium had no effect on the Trichoderma viride fungus growth, while at a concentration of 200 mg, the growth ceased. The (Lethal Concentration) Lc 50 was 102. 2 mg/100 ml, and 19/20 confidence limits being 83. 85 - 124. 6 mg.

Memoria para optar al título profesional de Ingeniero Agrónomo / El tomate (Solanum lycopersicum L.) ocupa el primer lugar dentro de las hortalizas demandadas en Chile. El alto consumo nacional obliga a los productores a mantener una alta oferta, prácticamente, de forma constante durante todo el año. Las condiciones desfavorables para la producción de tomate fresco (principalmente asociadas a rangos de temperatura y humedad no óptimas en el proceso de fecundación), exige disponer de estrategias agronómicas que logren sobrellevar las circunstancias desfavorables, frecuentemente registradas en invernaderos. Para el cultivo del tomate se han reportado efectos satisfactorios sobre la retención de frutos y la productividad con aplicaciones de reguladores de crecimiento. Sin embargo, la falta de información en torno al momento, la concentración y la forma de aplicación, ha generado incertidumbre sobre los potenciales beneficios. El objetivo de este ensayo fue determinar el efecto de la aplicación de benciladenina (BA) y ácido giberélico (GA3) sobre la retención de frutos y productividad en plantas de tomate. En un invernadero frío, bajo malla antiáfido, durante la temporada 2012-2013, se llevó a cabo un ensayo en la Facultad de Ciencias Agronómicas de la Universidad de Chile, La Pintana, Santiago. Se utilizaron plantas de tomate cv. Fiorentino injertados sobre patrón Emperador. Las concentraciones evaluadas fueron: 15 mg L−1 de BA, 10 mg L−1 de GA3 y la combinación de ambos reguladores de crecimiento. Las aplicaciones se realizaron a cada inflorescencia, en dos momentos fenológicos: botón floral cerrado y caída de pétalos. Las variables analizadas fueron número de flores y frutos por racimo, retención de frutos, masa media de frutos, diámetro polar y ecuatorial de frutos, número de semillas por fruto y largo de raquis. Las evaluaciones se realizaron en los primeros cuatro pisos productivos. No hubo efecto de interacción de los factores GA3 y BA para ninguna de las variables analizadas. La aplicación de 10 mg L−1 de GA3 redujo la producción, la masa media de frutos y el número de semillas por fruto. Sin embargo, este fitorregulador aumentó la longitud del raquis. Por otra parte, la aplicación de 15 mg L−1 de BA indujo un alto porcentaje de frutos de mayor calibre y redujo el número de los de menor tamaño. Se propone estudiar el efecto de concentraciones superiores. / Tomato fruit (Solanum lycopersicum L.) take the first place of the vegetables demand in Chile. The high national fruits consumption, require growers to support an elevated offer, practically, throughout the whole year. The unfavorable conditions for tomato production (mainly associated with non optimum temperature and moisture range in the fecundation process), require agronomy strategies to support adverse circumstances, registered frequently under greenhouse conditions. There have been suitable effects reported for tomato culture on fruit set and productivity with applications of growth regulators, however, the lack of time, concentration and optimum application procedure documentation has raised uncertainty of the real benefits. The aim was to determine the effect of benziladenine (BA) and gibberellic acid (GA3) application, on fruit set and production in tomato plants. A greenhouse experiment was develop, with cv. Fiorentino tomatoes grafted in Emperador rootstock plants, during 2012-2013 season, in the Faculty of Agricultural Sciences of the University of Chile, La Pintana, Santiago. Applications of 15 mg L−1 of BA, 10 mg L−1 of GA3, and a mixture of both growth regulators were tested. Each inflorescence was applied in two phenological stages: close flower bud and fallen corolla. The number of flowers and fruits per cluster, fruit set, average mass fruits, polar and equatorial diameter per fruit, seed number per fruit and rachis length were evaluated on the first four production floors. There was no interaction between GA3 and BA factors at any of the studied variables. The application of GA3 10 mg L−1 reduced production, fresh fruit mass and seed number per fruit, however, it increased the rachis length. Moreover, the application of BA 15 mg L−1 increased the high caliber fruit percentage and reduced the small sized fruit. The application of both growth regulators did not increase neither fruit size or the production. It is suggested to continue studying the effects of higher concentrations.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2007. / Härtill 4 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv. / Härtill 3 uppsatser.

Diss. (sammanfattning) Alnarp : Sveriges lantbruksuniversitet, 2004. / Härtill 4 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2004. / Härtill 5 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2005. / Härtill 4 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2007. / Härtill 5 uppsatser.