Aspectos fisiológicos e bioquímicos de genótipos de aveia branca em resposta à salinidade

• Ano de defesa: 2012
• Autor(a) principal: Timm, Fabiana Carrett
• Orientador(a): Moraes, Dario Munt de
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Pelotas
• Programa de Pós-Graduação: Programa de Pós-Graduação em Fisiologia Vegetal
• Departamento: Biologia
• País: BR
• Palavras-chave em Português: Fisiologia vegetal; Avena sativa L.; NaCl; Estresse oxidativo; Sementes
• Palavras-chave em Inglês: Avena sativa L.; NaCl; Oxidative stress; Seeds
• Área do conhecimento CNPq: CNPQ::CIENCIAS BIOLOGICAS::BOTANICA::FISIOLOGIA VEGETAL
• Link de acesso: https://guaiaca.ufpel.edu.br/handle/123456789/1988

The salinity negatively affects crop productivity due to osmotic and toxic effect caused by excess Na+ and Cl- in the soil. The mechanisms used by tolerant species include the control of Na+ uptake, compartmentalization and translocation of Na+ and Cl- by membrane transporters; production of protective osmolytes, increased activity of antioxidant enzymes and cell signaling. Thus, the objective was to evaluate seed germination and early growth of nine white oat genotypes, in order to identify contrasting genotypes for salt tolerance character. For this analysis was performed on the physiological white oat genotypes under different salt concentrations (0; 25; 50; 75 and 100 mM NaCl). The variables analyzed were: germination, first counting germination, index of germination speed, shoot and root length, shoots and roots dry mass of shoots and roots seedling. Based on these results were selected contrasting genotypes in which it was determined the activity of antioxidant enzymes and content of photosynthetic pigments. Seed germination was less affected than the growth of seedlings with increasing concentrations of NaCl, and the root length was most affected. The length of roots and shoots were the variables that best discriminated contrasting genotypes, enabling the identification of a tolerant genotype (URS 22) and sensitive (UPF 16), evidenced by the activity of antioxidant enzymes. The levels of chlorophyll and carotenoid were reduced in accordance with the increase in salt concentration in both genotypes, and lower in genotype UPF 16. Based on the analysis of initial growth was possible to discriminate a sensitive genotype (UPF 16) and a tolerant (URS 22), which showed higher and lower activity of antioxidant enzymes as well as lower and higher pigment contents, respectively.