Teor de clorofila, danos oxidativos e qualidade de sementes de soja
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Data
2010-06-21
Autores
Teixeira, Renake Nogueira [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
A retenção de clorofila tem afetado a produção de sementes de soja no Brasil, principalmente na região dos cerrados. Como conseqüência, tem-se a redução da qualidade dos lotes, constatada por queda na germinação e vigor, com prejuízos no estabelecimento de população adequada de plantas, no momento da semeadura. A degradação da clorofila pode ser afetada pelo estádio de maturação, por condições de secagem, aplicação de produtos químicos dessecantes e pelas condições climáticas, especialmente durante as fases de acúmulo de reservas e maturação das sementes. O processo de maturação, além de ter grande efeito na degradação da clorofila, influencia a produção de enzimas específicas da germinação. A presença do pigmento verde pode estar relacionada à produção de radicais livres que causam danos oxidativos, os quais afetam a longevidade das sementes. Este estudo teve como objetivo averiguar a relação entre a clorofila, a qualidade fisiológica e os danos oxidativos que afetam o potencial de conservação das sementes de soja. A pesquisa foi conduzida no Departamento de Produção Vegetal – Agricultura, da Faculdade de Ciências Agronômicas, UNESP, Campus de Botucatu. Os tratamentos constaram de 67 lotes de soja, de diferentes cultivares, provenientes de áreas dos Estados do Mato Grosso, de São Paulo e do Paraná, com variações nos graus de retenção...
The retention of chlorophyll has affected the production of soybeans in Brazil, mainly in the cerrado biome. As a result there has been a reduction in the quality of the lots, evidenced by a decrease in germination and vigor, with losses in the establishment of appropriate plants population at sowing time. The degradation of chlorophyll can be affected by ripening stage, by drying conditions, application of chemical desiccants, and climatic conditions, especially during periods of reserve accumulation and seed maturation. The maturation process, besides having great effect on the degradation of chlorophyll, has importance in the production of specific enzymes of germination. The presence of green pigment may be related to the production of free radicals that cause oxidative damage, which affects seed longevity. This study aimed to investigate the relationship between chlorophyll, the physiological quality and oxidative damage affecting the conservation potential of soybean seeds. The research was conducted at the Department of Crop Production - Agriculture, Faculty of Agronomic Sciences, UNESP, Botucatu. The treatments consisted of 67 soybean lots of different cultivars from areas in Mato Grosso, Sao Paulo and Parana, with variable degrees of chlorophyll retention. For each batch was determined the percentage of green seeds using a visual method of classification with the aid of the Munsell color card, and the chlorophyll content by chemical extraction, using the method of Arnon (1949) adapted in this study. The fluorometer was used to evaluate the photosynthetic activity of the seeds with chlorophyll retention. We evaluated also the oxidative damage suffered by each lot by determining lipoperoxide. All parameters were related to the quality of seeds valued at three times; initial date, soon after receiving the seed and after 3 and 6 months of storage. The data were analyzed by correlation... (Complete abstract click electronic access below)
The retention of chlorophyll has affected the production of soybeans in Brazil, mainly in the cerrado biome. As a result there has been a reduction in the quality of the lots, evidenced by a decrease in germination and vigor, with losses in the establishment of appropriate plants population at sowing time. The degradation of chlorophyll can be affected by ripening stage, by drying conditions, application of chemical desiccants, and climatic conditions, especially during periods of reserve accumulation and seed maturation. The maturation process, besides having great effect on the degradation of chlorophyll, has importance in the production of specific enzymes of germination. The presence of green pigment may be related to the production of free radicals that cause oxidative damage, which affects seed longevity. This study aimed to investigate the relationship between chlorophyll, the physiological quality and oxidative damage affecting the conservation potential of soybean seeds. The research was conducted at the Department of Crop Production - Agriculture, Faculty of Agronomic Sciences, UNESP, Botucatu. The treatments consisted of 67 soybean lots of different cultivars from areas in Mato Grosso, Sao Paulo and Parana, with variable degrees of chlorophyll retention. For each batch was determined the percentage of green seeds using a visual method of classification with the aid of the Munsell color card, and the chlorophyll content by chemical extraction, using the method of Arnon (1949) adapted in this study. The fluorometer was used to evaluate the photosynthetic activity of the seeds with chlorophyll retention. We evaluated also the oxidative damage suffered by each lot by determining lipoperoxide. All parameters were related to the quality of seeds valued at three times; initial date, soon after receiving the seed and after 3 and 6 months of storage. The data were analyzed by correlation... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Soja, Sementes - Qualidade, Clorofila - Analise, Lipídeos, Glycine max, Chlorophyll, Lipid peroxidation
Como citar
TEIXEIRA, Renake Nogueira. Teor de clorofila, danos oxidativos e qualidade de sementes de soja. 2010. vi, 92 f. Dissertação (mestrado) - Universidade Estadual Paulista, Faculdade de Ciências Agronômicas de Botucatu, 2010.