Abstract

Seeds of Argyrolobium uniflorum (Fabaceae), a spontaneous plant in arid and semi-arid regions of Tunisia, showed a color variability in their seed coats (green, orange, yellow and brown). The influence of the color of seed coat on germination and phytochemical seed composition was evaluated. Germination tests were carried out and the results obtained show that the applied chemical treatment (sulfuric acid) improved germination, independently of the color tested. In addition, this plant germinated at a temperature range of 10 to 30°C, where each color requires a suitable temperature. Brown seeds have the highest percentage of germination. Total polyphenolic contents of different colors of seeds were studied using three solvents. The yellow seeds TPC was found higher than that of the green, brown and orange colors, with the highest values in acetone extract reaching 7.98 and 8.68 mg EAG g^-1 MS. However, the level of antioxidant activity estimated by DPPH (EC₅₀ = 0.24 to 1.84 mg / ml) also showed that the yellow seeds exhibit the lowest value (EC₅₀ = 0.24 mg / ml). The highest values of flavonoids were observed in the seed brown with values 3 mg EC g^-1 MS. Germination associate with the colors of coat of seeds were to be a good process to improve the phenolic content and antioxidant activity of A. uniflorum seeds.

Key words: Argyrolobium uniflorum, germination, colors, antioxidant activity.