Crescimento e mobilização de carboidrato em embrião de sementes de fedegoso (Senna macranthera Irwin et Barneby) durante a germinação

Abstract

The fresh and dry weights, the length, the starch content and of oxidating sugars were evaluated in both embryos, isolated or not, from fedegoso seeds (Senna macranthera Irwin et Barneby). The cotyledons weight grew in water during three days, under constant light in 25°C. The weight of the fresh embryos increased, so much in the isolated embryos as well as in the whole seeds, being larger in the first one. Small decrease was observed in the weights of the dry embryos, clearly in the isolated embryos. There was constant increase in the length of the isolated embryos, while in those of whole seeds there was small increase in the first 24 hours, being stabilized to proceed. The concentration of reducing sugars decreased in the isolated embryos, keeping constant in those of whole seeds. The content of starch presented reduction in both embryo types, with decrease more accentuated in those of whole seeds . Small reduction was observed in the weight of dry cotyledons after 48 hours of soak. It was concluded that the soak causes elongation of the embryonic axis, being larger in those without the restriction of the embryo covers. During the elongation there is consumption of reserve, however they are used for deposition in the cellular wall, given that it was not observed great variation in the dry matter weight.