Efeitos da luminosidade na germinação e no desenvolvimento de arbóreas nativas de Mata Atlântica

• Autor(a) principal: Paradizo, Inayá Castiglioni
• Data de Publicação: 2011
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Espírito Santo (riUfes)
• Texto Completo: http://repositorio.ufes.br/handle/10/9985
• topic: Espécies nativas; Germinação; Crescimento; Agronomia; Radiação solar; Plantas - Anatomia; Etileno; 57

We call germination the period of the life’s circle that is relationed with plants distribution. The radiation for the plant is not only one source of energy, but is an incentive governing the development and also can be a stressful factor. To comprehend all stages of a vegetal community, as the survival and regeneration of the habitat, a lot of studies about the eco-physiology of germination and the effects of luminosity radiation are important. In this context, the objective of this study was: Chapter 1: a) Determinate the great conditions of the germination of Angico, P. dubium, and Braúna, M. brauna, in relation between luminosity intensity(light, dark and photoperiod), temperature (20,25,30,35 and 40ºC) and rupture of dormancy with mechanic scarification; b) Quantify the production of nitric oxide and ethylene during the germination of the species described as a result of the luminosity intensity struck : dark, low light (50 photons), media light (250 photons) and high light (1200 photons); c) Contrast the nitric oxide production with the percentage of germination of Angico, adding one “kidnapper” of nitrogen (c- PTIO) to the water available to the seed, and adding one donator of nitrogen (SNP). Chapter 2: a) Verify the photossyntetisis pigment’s quantity made in sun plants and shadow plants of Peroba and Jequitibá; b) Analysis of fluorescence of chlorophyll in the different species and treatments; c) Quantify the carbohydrates made in the xylem walls and of bark; d) Carry out the growing analysis in the species in the initial time and after 60 days of treatment; e) Visualize the anatomic and histochemical differences between the species in a direct sunray and in the shadow. It was determinate the great conditions of germination, percentage of germination, IVG, TMG and VMG. The angico, P. dubium, has the best coefficient of germination in light, temperature between 25 and 30ºC, with its seeds scarificated. The production of No for the specie is highest in the dark, being this factor stressful for the seeds. Although, in high luminosity intensity, even the percentage of germination being lower, the production of ethylene offered the germination of some seeds. The function of nitrogen in the sinalization of the germination is confirmed with the treatments of c-PTIO and c- PTIO + SNP. The interation between No and ethylene is antagonist for the germination of the seeds, being made a high quantity of NO in the first 24 hours, after is made the ethylene, breaking the production of NO. For Braúna, the specie has germinative comportament only in the dark with 30º C of temperature. In spite of angico, braúna make for quantity of NO when they are in great conditions, being the production lower when the seeds are in stressful of light. C. legalis, jequitibá, can be considered one specie with big phenotype plasticity, even so of the photochemical rendiment of fluorescent of chlorophyll it’s not ideal in the treatment of dun, the same show outline the problem and keep a good growing and adaptation of the new sun conditions. Perobaamarela, P. peroba, can’t be considered a sun plant, but a shadow plant. Although the same didn’t have good results in all parameters analyzed when were in sun treatment. The same specie had anatomics anomalies in the leaves, caused by the high luminosity intensity. Therefore, the species can be used for recuperation of degraded areas, but the suggestion is first plant seedlings of Jequitibá to shade the place, and then plant the seedlings of Peroba. However, a lot of studies about ecophysiology of this species still have to be done, to have a better comprehension of comportament before the ambiental conditions, both biotic as abiotic.