Germinação e vigor de sementes de soja em condições de estresses térmico e salino

Abstract

The knowledge about the optimal conditions for the development of crops is of fundamental importance for a successful production since species growth stages can be negatively affected by abioct factors such as temperature and salinity, especially under stress conditions. As a result, the present work aimed to evaluate the germination and vigor of soybean seeds, Glycine max cv. 5T7971PRO, under conditions of heat and salt stress. The experiment was set up in Germitest® paper rolls moistened with distilled water (control) or saline obtained by diluting sodium chloride (NaCl) in distilled water at concentrations of 3, 6, 9, 12 and 15 dS m-1, which were kept in B.O.D type germinators at constant temperatures of 20, 25, 30 and 35°C for 10 days. The variables analyzed were germination, germination speed index, length, dry matter and concentration of ions, sodium and potassium, in the root and shoots of seedlings. The results that presented a significant difference at the 5% level had behavior represented by regression models. With the exception of germination, the other vigor variables analyzed showed little tolerance to the effects of increased salt concentrations and temperature, with more severe results observed at 15dS m-1 and 35ºC.