Alterações fisiológicas e bioquímicas na pré-hidratação de sementes de soja

Abstract

Seeds of soybean when subjected to fast hydration an suffer da mage by imbibition, which may be more or less pronou nced depending on the cultivar and the initial water content of seeds. The objective of this work was to study physiological and biochemical alterations, with emphases in the electrolyte leakage and in the expression of different isoenzym atic systems, determined by m ethods of pre-hydration to reduce the damage by imbibition. Three lots of each cultivar, CD 202 and CD 215, uniform in size, characterized for the water content, germination, first germ ination counting, accelerated aging, electrical condu ctivity and seedling emergence in the field, were used. The water content of seeds have b een adjusted to 7.5, 10.5 and 13.5%. Next, the seeds were subjected to pre-hydration treatm ents in saturated atmosphere and substrate moistened, during 4 and 6 hours. The seeds were evaluated by tests of electrical conductivity after 18 and 24 hours of imbibition, germination, emergency of seedlings in the field , and leakage of calcium , potassium and m agnesium. They were also characterized as to th e pattern of expression of isoe nzymatic systems Malato Desidrogenase, Glutamate Desidrogenase, Ac id Phosphatase and Esterase Acid. T he treatments with pre-hy dration in s aturated atmosphere and in m oistened substrate, during 4 and 6 hours, were efficient in reduc tion of da mage of seeds with low water content, sendo mais expressivo nas sem entes da cultivar CD 202. No entanto, …Seeds of soybean subjected the pre- hydration presented alteration of isoenzymatic profiles of acid phosphatase and malate dehydrogenase enzymes.