Estresse hídrico na fisiologia da germinação e morfoanatomia de plântulas de Myracrodruon urundeuva Fr. All. (Anacardiaceae)

• Autor(a) principal: Silva, Givanildo Zildo da
• Data de Publicação: 2014
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFPB
• Texto Completo: https://repositorio.ufpb.br/jspui/handle/tede/8026
• topic: Caatinga; Caatinga; Viabilidade; Vigor; Adaptação morfoanatômica; Viability; Vigor; Morphological; CIENCIAS AGRARIAS::AGRONOMIA

The Caatinga Biome, even with the approach of recent years, is a region lacking of information that enables the understanding of how plants survive on stress conditions. Species that make up this biome, Myracrodruon urundeuva Fr. All. stand out for timber and medicinal properties, suffering for decades, intense and predatory exploitation, leading to compose the official IBAMA list of endangered flora. The aim of this work was to select individuals of M. urundeuva through viability and vigor tests and to evaluate the effect of water stress on seedling emergence of normal and morphoanatomy. For such individuals mastic were selected in three areas of Paraiba State, a municipality of the ray tracing and two in Boa Vista, in which diasporas were collected and sent to the Laboratory of Seed Analysis (LAS) UFPB, Areia-PB. Initially it has proceeded to determine the water content (TA) and the following assessments: Germination test (GT), emergency testing (ET), first count of germination and emergence (FCG and FCE), germination speed index and emergency speed index (GSI and ESI), length and dry weight of seedlings. The methodology for implementing saline accelerated aging was also determined. Thereafter individual diasporas (matrix) more vigorous of the three areas were subjected to water stress under conditions of retention capacity of the soil levels: 10, 15, 20, 25, 30, 35, 40, 45, 50, 55 and 60%. In this step we assessed the TA, TE, PCE, IVE, length and dry weight of roots and shoots of seedlings. To evaluate the morphoanatomy, diasporas mastic were subjected to the same continuous water conditions, described above, and a second temporary water condition. For this, they were initially sown in the soil retention capacity of 60%, then to simulate drought with stopping of watering until obtaining the capacities of 10, 15, 20, 25 and 30% retention. After subjected to continuous and temporary water conditions, morphoanatomical characteristics evaluated were: number of leaves, length and width of the primary, length, width and thickness of the central leaflet leaf; length, width and thickness of the cotyledon; number of stomata in the leaf and cotyledon length and diameter of the stem and root. In the initial evaluation of the seeds was observed that individuals of M. urundeuva germination and vigor have differentiated between the collection areas, as well as within the same area, demonstrating the adaptive plasticity of the species. The accelerated aging test in saline temperature of 41 °C during 24 hours is recommended due to the reduction of fungi, the eleventh individual, the stronger this test. When the eleventh individual diasporas were subjected to water stress, it was found that they have some degree of demand relative to water in the early periods of development. The structural and physiological assessments seedlings have adaptive characteristics for perpetuation over time and space in a natural environment. As for water regimes applied in the evaluation of morphoanatomical characteristics, treatments affected seedling development of mastic, and capabilities between 50 and 60% retention of the best treatments for the production of normal seedlings, for most variables.