Physiological potential of soybean seeds under hypoxia and salinity stress

Resumo

Adverse factors affect the physiological performance of soybean seeds during field establishment. This study evaluates the physiological potential of Intacta soybean seeds under hypoxia and salinity stress, by submersion in water using different osmotic potentials. In both situations, three intact soybean cultivars (TMG 7062 IPRO, 63i64 RSF IPRO, 7166 RSF IPRO) were tested in the laboratory. To test the effect of hypoxia, the seeds subjected to the tests were previously immersed in water for periods of 0, 6, 12, 24, and 48 hours. In the evaluation of salinity stress, towel papers were moistened with different solutions of potassium chloride (KCl) (0.0; -0.4; -0.8; and           -1.2 MPa). Seed germination and vigor (first germination count, shoot length, primary root length, and seedling dry biomass) were evaluated. Seed germination was negatively affected by the 12-hour period of hypoxia. Cultivars 763i64 and 7166 were more tolerant to hypoxia conditions. Cultivar 7062 was more tolerant to salinity stress. Osmotic potential of -0.4 MPa affected the vigor of soybean seeds. Soybean cultivars showed adaptive differ­ences under hypoxia and salinity stress.