Alterações fisiológicas e bioquímicas em sementes de jacarandá-da-bahia (Dalbergia nigra) ((Vell.) Fr. All. Ex Benth) sob estresse térmico

• Autor(a) principal: Matos, Antônio César Batista
• Data de Publicação: 2013
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/3151
• topic: Floresta; Germinação; EROs; Enzimas; Forest; Germination; EROs; Enzymes; CNPQ::CIENCIAS AGRARIAS::RECURSOS FLORESTAIS E ENGENHARIA FLORESTAL::SILVICULTURA

The seeds germination is abiotic factors dependent, being the temperature one of the most important, influencing differently in metabolic activity. In an ideal range, temperature stimulates germination, but in extreme conditions, causes damage to the seeds. This study aimed to investigate the different temperatures effect during the seeds germination of Dalbergia nigra and its implications on the seeds physiology and biochemistry. The seeds were collected in the Viçosa-MG region, in September 2012. It was evaluated the germination percentage, the membrane integrity, the superoxide anion (O2.-) and hydrogen peroxide (H2O2) production, and the action of the antioxidante defence system, quantifying the activity of the enzimes superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and peroxidase (POX) in the different exposure times to temperatures of 5, 15, 25 (control), 35 ads 45 oC. There was not germination at the 5 and 45 oC. The membrane semipermeability was not recovered at the 5 and 45 oC. The superoxide anion and hydrogen peroxide production reduced with the seeds rehydratation in all temperatures. There is an effective activity of the enzymes SOD and POX in all temperatures and times evaluated. The activity of APX just is detected in the initial phase of imbibition at the 5 and 45 oC. The CAT activity is not detected after 48 hours of imbibition at the 45 °C.