Qualidade física e fisiológica de sementes e crescimento inicial de mudas Enterolobium maximum Ducke

• Ano de defesa: 2014
• Autor(a) principal: Farias, Carla Caroline Magalhães
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal do Espírito Santo; BR; Mestrado em Ciências Florestais; Centro de Ciências Agrárias e Engenharias; UFES; Programa de Pós-Graduação em Ciências Florestais
• Palavras-chave em Português: Luminosity; Substrate; Stress; Dormancy; Dormência; Luminosidade; Estresse; Plantas - Efeito da luz; Substratos; Sementes; Recursos Florestais e Engenharia Florestal; 630
• Link de acesso: http://repositorio.ufes.br/handle/10/5035

Enterolobium maximum Ducke is a Fabaceae (Mimosoideae) large size, typical of the Amazon Forest. The objective of this study was to investigate the physical and physiological seed quality and seedling growth of Enterolobium maximum. The work was conducted at the Laboratory of Seeds and in the greenhouse at CCA/UFES in Alegre-ES. Seeds were collected from matrices in the municipality of Alta Floresta, MT. Were measured and / or assessed the length, width, thickness, initial moisture content, weight of 1000 seeds and number of seeds per kilogram. The imbibition curve of intact seeds and scarified by soaking in distilled water, on paper and roll paper, and volume of seeds in common, distilled and type I water was taken. To evaluate the overcoming of dormancy, the treatments were used: 1) intact seeds (control); 2) mechanical scarification; 3) mechanical scarification + GA3; 4) mechanical scarification + KNO3; 5) GA3; 6) H2SO4/10"; 7) H2SO410"+GA3; 8) H2SO4/10"+KNO3; 9) H2SO4/15"; 10) H2SO4/15"+GA3; 11) H2SO4/15"+KNO3. Emergence, index of germination speed, stem diameter, shoot length and roots, leaf area, dry masses and were evaluated roots. To study the initial growth of seedlings in different substrates Enterolobium maximum brightness and the seeds were mechanically scarified and sown in bags containing substrates: soil+biosolid, manure+soil+sand and soil+sand+substrate business (HS Forest®). The light intensities used were: 1165; 417.4; 140.32 and 57.82 micromol photons m-2 s -1 obtained with the aid of black shading screen 50% (polyolefin). Were evaluated: emergence, mean emergence time, survival, height, root length, stem diameter, leaf area, dry weight of shoot and root, Dickson quality index, chlorophyll content and ratio of chlorophyll a/b. In the study of the physiological quality of seeds subjected to water and salt stress osmotic agents CaCl2, KCl, NaCl and mannitol were used for potential 0.0 (control), -0.2; -0.4; -0.6; -0.8 and -1.0 MPa. The percentage of germination were evaluated, the rate of germination rate, the germination time, the relative frequency of germination, the percentage of normal and abnormal seedlings, the length of the shoot and root. According to the results of the seeds had an average length of 19.03 mm, 11.53 mm wide, 6.43 mm thick and 1.05 g of dough.The initial moisture content was 8.68% mass of 1000 seeds is 964.59 g, and containing on average 1037 seeds kg-1. The seeds show dormancy imposed by the impermeability of the integument. Mechanical scarification with sandpaper is an efficient method to overcome the tegumentary seed dormancy. The seedling growth is favored in an environment with luminosity of 417.4 micromol photons m-2 s -1. The substrate soil+commercial substrate (HS Forest®)+sand is the most recommended for the development of seedlings under scheme luminosity of 417.4 micromol photons m-2 s -1. The variation in brightness changes the index of total chlorophyll and the ratio of the rate of chlorophyll a / b of the plants leaves. Seed vigor decreased with reduced water potential of solutions from -0.2 MPa. The mannitol induced water stress is less severe than the salt stress with CaCl2, KCl and NaCl. The solutions of NaCl and CaCl2 determine toxicity in Enterolobium maximum seeds from -0.6 MPa.