Antioxidant and physiological responses of seeds of soybean cultivars to delayed harvest

Abstract

Soybean seeds are susceptible to field deterioration after reaching physiological maturity, which usually occurs at the R7 stage, with harvest at R8. This study aimed to evaluate the biochemical and physiological changes in seeds of different soybean cultivars submitted to delayed harvest in the field. Seeds of the cultivars NS 5959, BMX Potência, and TMG 1175 were harvested at four times (0, 10, 20, and 30 days after reaching R8). Moisture, germination, first count, accelerated aging, emergence, and tetrazolium tests were performed in each harvest period. The activities of the antioxidant enzymes catalase (CAT), peroxidase (POX), and ascorbate peroxidase (APX) were also evaluated. The experiment was carried out in a completely randomized design in a 3×4 factorial scheme (three cultivars and four harvest times). A reduction in germination and vigor of seeds of different soybean cultivars was found at R8 + 20 and R8 + 30 days related to field deterioration due to delayed harvest. The seeds of the cultivars did not differ in terms of viability under delayed harvest but differed in terms of antioxidant and physiological responses. Better and worse seed performances were found for the cultivars BMX Potência and TMG 1175, respectively, at R8 and in R8 + 10 days.