Antioxidant defenses determine the maturation and physiological quality of in vitro Euterpe edulis Martius seeds

Abstract

Abstract The palm Euterpe edulis Martius is native to the Atlantic Forest. The nutritional composition and antioxidant potential of its fruits are superior to those of Euterpe oleracea and Euterpe precatoria. The present study aimed to analyze the antioxidant defenses associated with in vitro germination of E. edulis and the quality of its seedlings. Seeds were harvested at 29 maturation stages (94–290 days after anthesis, DAA), and characterized in terms of budding, vigor, seedling formation, antioxidant defenses (superoxide dismutase, catalase, ascorbate peroxidase, and anthocyanins), hydrogen peroxide, lipid peroxidation, and hormonal composition. Fruit dry mass and volume did not differ from 241 DAA; whereas seed dry mass peaked 255 DAA, decreasing after this period. Seed moisture decreased throughout maturation. Seedling-related variables achieved the highest average values 227 DAA. The seeds showed maximum germination, vigor, percentage of normal seedlings, concentration of ZEA and ABA at 164 DAA. From 269 DAA, a decrease in dry mass suggested increased reserve consumption (respiration), inhibition of nutrient translocation to seeds, and reduction in water content (desiccation). The resulting greater sensitivity to environmental variations coincided with increased oxidative stress, but was counteracted by antioxidant defenses.