Superação de dormência em sementes de garapa (Apuleia leiocarpa (Vogel) J. F. Macbr.)

• Ano de defesa: 2010
• Autor(a) principal: Castro, Dayene Schiavon de
• Orientador(a): Araújo, Eduardo Fontes
• Banca de defesa: Reis, Múcio Silva , Ventrella, Marília Contin
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Fitotecnia
• Departamento: Plantas daninhas, Alelopatia, Herbicidas e Resíduos; Fisiologia de culturas; Manejo pós-colheita de
• País: BR
• Palavras-chave em Português: Garapa; Dormência; Sementes
• Palavras-chave em Inglês: Garapa; Dormancy; Seeds
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA
• Link de acesso: http://locus.ufv.br/handle/123456789/4528

The garapa (Apuleia leiocarpa) is an arboreal species with wide dispersion throughout Brazil, being widely used in reforestation programs and the recovery of degraded areas. The species has suffered a reduction in the number of individuals in their natural habitat due to uncontrolled commercial exploitation. In addition, the seedlings may be limited depending on the delay in germination. The objective of this research to evaluate methods for overcoming seed dormancy in garapa. The survey was conducted in the laboratory and the seed at the Center for Microscopy and Microanalysis, Federal University of Viçosa, from August 2008 to May 2009. In the first experiment, seeds were scarified and not scarified used for the preparation of the imbibitions curve. In the second experiment, seeds were subjected to treatments to overcome dormancy. Then they were evaluated by germination, first count of germination, speed of germination and seedling length. For some treatments, the seeds were also analyzed by scanning electron microscopy. To overcome dormancy, the treatments included hot water (80ºC) for 30 seconds, sulfuric acid 75 and 98% for 1, 3, 5, 7 and 9 minutes; dry heat (40ºC) for 72 and 96 hours, wet heat ( 60ºC) for 24 and 48 hours, 10% sodium hypochlorite for five times (5,0; 7,5; 10,0; 12,5 and 15,0 hours). The statistical design was completely randomized design with 4 replications. Data from the sulfuric acid factorial 2 X 5 + 1, were submitted to regression, the F test and Dunnett's test to the 5% level of probability. The heat treatment was subjected to analysis of variance, Tukey's test and Dunnett, at 5% probability. For sodium hypochlorite was performed analysis of variance and regression. After each treatment, seeds were evaluated for germination (normal seedlings, abnormal seedlings, dead seeds and hard seeds) and vigor (first count of germination, speed of germination and seedling length). Garapa scarified seeds following a three-phase model of imbibitions and radicle protrusion occurs around 72 hours. Immersion in water heated to 80ºC for 30 seconds caused the death of the seeds of garapa. Scarification with sulfuric acid, regardless of concentration and exposure time, was effective in overcoming the dormancy of seeds of garapa. Treatments with dry heat, wet heat and sodium hypochlorite partially overcome the impermeability of the seed coat of garapa.