Efeito da disponibilidade hídrica do substrato, DA QUALIDADE FISIOLÓGICA E do teor de água inicial das sementes de soja no PROCESSO de germinação

With the main purpose of studying the relations among water availability, moisture content, and seed physiological quality on the germination process, seeds from three soybean [Glycine max (L.) Merrill] lots of the cv. IAC-15 with different levels of physiological quality, were used. Moistening of the seeds was accomplished to reach three moisture levels: 90, 110 and 130g of water.kg-1 fresh weight. The seeds of each lot, with 90, 110 e 130g of water.kg-1 were placed under different water potentials to germinate in soil and paper towel substrates. Moistening of paper towels was done with polyethylene glycol solutions, with water potencials of -0.04, -0.10, -0.20 e -0.40 MPa. Soil moistening was based on a water retention curve, adding a corresponding volume of water to reach the same water potencials as above. Speed and percentage of seedling emergence from soil were evaluated; radicel protrusion at three days after instalation, abnormal seedling and germination percentages at the seven days after seeding were determined from the paper towel sustrate. The data analysis and the results led to the following conclusions: There is a relationship between physiological quality and moisture level of seeds during the germination; the water potencials of -0,20 e -0,40 MPa considerably reduce the germination; the water potencial of -0,40 MPa decreases the seedling emergence of soybean.

Glycine max; soybean; seed; germination

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