Mobilização de reservas no eixo embrionário e nos cotilédones de sementes de <i>Schizolobium parahyba</i> (Vell.) S. F. Blake durante a germinação

Abstract

RESUMOO conhecimento da composição química da semente é de extrema importância para auxiliar o entendimento do comportamento durante a germinação, o armazenamento ou mesmo nos processos metabólicos envolvidos na degradação dessas reservas, que, em última instância, afetam o vigor das sementes. Dessa forma, o objetivo deste trabalho foi estudar as alterações no conteúdo de carboidratos, lipídios e proteínas nos cotilédones e no eixo embrionário, durante a germinação de sementes de Schizolobium parahyba (Vell.) S. F. Blake. Para tanto, as sementes foram colocadas para germinar e retiradas amostras periodicamente para as análises. A porcentagem de germinação foi de 88%, iniciando-se no 9 o dia, e a velocidade de germinação foi de 7,7 sementes. ABSTRACTKnowledge of seed chemical composition is very important in order to understand behavior during germination, storage and metabolic processes involved during reserve degradation, the latter of which affects seed vigor. The objective of this study was to assess changes in carbohydrates, lipids and proteins in the embryonic axis and in cotyledons during germination of Schizolobium parahyba. Seeds were placed in Petri dishes to germinate and samples were removed periodically for analyses. Germination was 88%, starting on the ninth day, and the germination rate was 7.7 seeds.day -1 . Among fatty acids, oleic acids predominated in the embryonic axis and in cotyledons, with changes occurring during the observation period. The others fatty acids showed little change. The levels of starch and soluble carbohydrate behaved in a similar manner in both compartments with a decrease during the imbibition period. Protein levels in the embryonic axis decreased by the eight day, after increasing for two days. On the other hand, protein levels in cotyledons remained constant during the first two days, decreased on the six day and increased on the eight day.

Alterations in seed reserves of Dalbergia nigra ((Vell.) Fr All. ex Benth.) during hydration

“…The use of sugars for respiration was observed during the germination of Schizolobium parahyba, with a clear reduction during the initial soaking and a subsequent stabilization in the cotyledons between 2 and 8 days (Magalhães et al, 2010). In a study on reserve mobilization in Aniba rosaeodora seeds, there was a 30% reduction in soluble sugars when the radicle length was 2-5 cm, with this mobilization being associated with the formation of the first leaf (Lima et al, 2008).…”

Degradation of reserves of crambe seed (Crambe abyssinica) during germination

“…The data relating to starch content in the seed set to a downward quadratic regression equation indicates the intake and mobilization of reserves during the germination period (Figure 3). According to Magalhaes et al (2010), starch provides glucose to be used both as air for breath, to generate electricity, and to compose physical structures for embryo growth during germination phase.…”

Plant growth regulators and mobilization of reserves in imbibition phases of yellow passion fruit

“…(grápia), observed that the average content of soluble sugars did not differ significantly during the soaking period, nonetheless, there was a tendency to mobilize these reserves during this period. Magalhães et al (2010) found that the levels of total soluble carbohydrates in seeds of Schizolobium parahyba (Vell.) Blake (guapuruvu) showed marked reduction during the initial phase of soaking, and that this energy consumption is related to the respiration of seeds soon in the beginning of the imbibition process.…”