Comportamento fisiológico e bioquímico de sementes de girassol submetidas ao armazenamento convencional e câmara fria

Abstract

The sunflower cultivation is strategic mainly as crop rotation on offseason periods and for the development of industrial oil. The culture is important in some regions, especially in the Midwest, and the use of high quality seeds is essential for ensuring high productivity. Mainly due to biochemical features, there is the need to store the seeds under favorable conditions in order to maintain their quality until sowing. This study included sunflower seeds of two commercial hybrids, Helio 250 and Helio 251, which were subjected to storage in both environments. Seeds were stored for a period of eight months in the conventional storage and freezer. Seed quality was evaluated at 0, 2, 4, 6 and 8 months of storage, through germination, speed of germination index, accelerated aging, emergency test (IVE), emergence index and water content. It was assessed the expression of proteins by electrophoresis and chemical composition of the seeds in each storage period. The freezer storage is more efficient for the conservation of sunflower seed quality. Changes in sunflower seed quality can be detected by enzyme analysis, except for the glutathione peroxidase. High content of oleic fatty acid does not influence the quality of sunflower seeds. The proportion of fatty acids is changed after storage.