Carbohydrate mobilisation in germinating seed of Enterolobium contortisiliquum and Peltophorum dubium (Fabaceae), two tropical trees used for restoration

Abstract

Enterolobium contortisiliquum (Vell.) Morong. and Peltophorum dubium (Spreng.) are two leguminous species native to Brazil that are frequently used to restore degraded areas. Seed of E. contortisiliquum are exalbuminous, whereas seed of P. dubium have a mucilaginous endosperm and both are orthodox, dormant and have a water-impermeable seed coat. There is little information about the dynamics of their germination and understanding this process is important for propagation, conservation and satisfactory practices for restoration of degraded areas. Thus, in this study we evaluated and compared the carbohydrate mobilisation of the seed of both species during germination and early seedling development. Data obtained showed differences in the composition and in the mobilisation of the storage carbohydrates in the studied species. Whereas the main storage of the E. contortisiliquum embryo is starch, the main reserve found in P. dubium is the galactomannan stored in the endosperm. The carbohydrates first hydrolysed in both species are raffinose family oligosaccharides that are used in the embryo development during germination. Starch found in cotyledons of E. contortisiliquum or accumulated after galactomannan degradation in the embryo of P. dubium is not used during germination and early seedling growth in either species.