HIGH-PRESSURE TREATMENT ACCELERATES GERMINATION OF WINGED BEAN-SEEDS

High hydrostatic pressures (30-200 MPa) have been utilized for accelerating the germination of winged bean (Psophocarpus tetraganolobus, 'Urizun') seeds. This pressure treatment promoted rapid germination of seeds and increased the germination percentage; it was especially effective in the germination of hard seeds. To confirm the acceleration mechanism of germination, water absorption parts were investigated under the pressure treatment. Furthermore, the changes in the water absorption content, leakage of solutes from seeds and individual sugar contents were also analyzed. As a result it is assumed that the effect of pressure treatments is at least partially physical leading to the improvement of water penetration, especially through the micropyle and seed coat, with a resulting acceleration of hydrolysis of sugars and other physiological processes associated with germination.