Mestrado em Biodiversidade Vegetal (ICB)
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Navegando Mestrado em Biodiversidade Vegetal (ICB) por Por Orientador "Melo, Hyrandir Cabral de"
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Item Respostas bioquímicas e fisiológicas de mutantes fotomorfogenéticos de tomateiro (Solanum lycopersicum L. cv. Micro-Tom) sob deficiência hídrica(Universidade Federal de Goiás, 2015-02-26) Alves, Frederico Rocha Rodrigues; Melo, Hyrandir Cabral de; http://lattes.cnpq.br/9055607630353419Phytochrome-dependent physiological processes are being unveiled by photomorphogenic mutant plants. In tomato (Solanum lycopersicum L.), the aurea mutant is phytochrome-deficient and the high-pigment 1 mutant (hp1) has exaggerated light responses. Phytochromes are related to many abiotic and biotic stress responses due to its role in the regulation of specific genes transcription, acting upon biochemical and molecular mechanisms of cell signaling. Here, we examined the effects of water-withholding over water potential, leaf gas exchanges, chlorophyll fluorescence parameters and chloroplast pigments content in photomorphogenic tomato mutants aurea and hp1, as well its wild-type cultivar Micro-Tom (MT). The plants were grown in a greenhouse under controlled conditions of temperature (24-27ºC) and humidity (60-70%). Analysis were made in 35-days-old plants (n=5) which irrigation was suspended for 5 days and then rehydrated in the sixth day. As control, five plants of each genotype remained well-watered. Water-withholding decreased the water potential and affected leaf gas exchange rates in all studied genotypes, decreasing rates of photosynthesis and stomatal conductance from the fourth treatment day on. Initial fluorescence and PSII potential quantum efficiency were not affected by the water-withholding treatment in general, but MT showed significant decrease in PSII operating efficiency and electron transporte rate as well as an increase in non-photochemical quenching parameters, facts not registered for the mutants during the treatment period. hp1 mutant has the highest content of chlorophyll a, chlorophyll b and carotenoids, this last playing a central role in the oxidative stress defense. Under water-withholding conditions, MT presented the highest MDA concentration and aurea displayed high activities of catalase, peroxidase and ascorbate peroxidase when compared to the other genotypes. The present data allows the conclusion that the mutants have higher tolerance to drought stress than the wild Micro-Tom genotype.Item Características morfofisiológicas, produção e composição de óleo essencial em folhas de Tetradenia riparia (Hochst) Codd- Lamiaceae cultivada em diferentes níveis de sombreamento(Universidade Federal de Goiás, 2014-02-26) Araújo, Laís Lima Nabuco; Melo, Hyrandir Cabral de; http://lattes.cnpq.br/9055607630353419MORPHOPHYSIOLOGICAL CHARACTERISTICS, PRODUCTION AND COMPOSITION OF ESSENTIAL OIL IN LEAVES OF Tetradenia riparia (Hochst) Codd-LAMIACEAE CULTIVATED AT DIFFERENT LEVELS OF SHADING. Tetradenia riparia ( Hochst ) Codd- Lamiaceae, popularly known as incense, is used for diseases like malaria, angina, gastroenteritis , headaches , bronchitis , among other diseases. Its essential oil contains approximately 200 components. The diterpenoids have antimicrobial, antispasmodic and antitricomonas activity. Considering the importance of light on plant growth and development the present study aims to evaluate morphological and physiological characteristics and production and composition of essential oil of Tetardenia riparia cultivated at different levels of shading. For this, seedlings were propagated by stem cuttings and grown in mini-greenhouses completely covered with black polyethylene screens produced to provide 30%, 50% and 80 % of levels shading and also grown under open sky. Leaves were evaluated after 150 days of treatment. The plants under open sky had greater foliar blade thickness. Shaded plants had higher leaf area. There were no significant differences in stomata and trichomes in the abaxial epidermis. The highest oil yield occurred in plants grown with 30 % and 50 % shading treatments. The major component of the essential oil, regardless of the treatment, was the sesquiterpenic hydrocarbon 14 - hydroxy -9 - epi - (E) - caryophyllene. Many chemical compounds of the essential oil alter its content according to treatments and other compounds were only observed at specific levels of shading. The total content of chlorophyll, chlorophyll “a” and carotenoids was higher in 50% and 80% treatment shading. The levels of chlorophyll “b” and a / b ratio did not change in different treatments. The different treatments did not change values of ash. The lipid content was lower in the treatment of 80% and increased protein and nitrogen content in 50% and 80% treatment shading.