Molecular aspects during seed germination of Erythrina velutina Willd. under different temperatures (Part 1): reserve mobilization

Aspectos moleculares durante a germinação de sementes de Erythrina velutina Willd. sob diferentes temperaturas (Parte 1): mobilização de reservas

ABSTRACT:

Erythrina velutina Willd. (Fabaceae) is a tree species that bears social, ecological, and economic importance for northeastern Brazil, a region with frequent temperature variations. The objective of this work was to evaluate the mobilization of reserves during seed germination and seedling establishment of E. velutina at different temperatures, and how these mechanisms are affected in a thermal-stress situation. The seeds germinated at 5, 15, 25, 35, and 45 °C, and the physiological and biochemical aspects of reserve mobilization (starch, lipids, and total proteins) were assessed during seedling establishment. Germination, vigor, and the mobilization of reserves from the cotyledons to the embryonic axis are affected according to the incubation temperature. The temperature of 25 °C favors the mobilization of reserves during seed germination and seedling establishment in E. velutina. In a situation of thermal stress, high temperatures affect the establishment of the seedlings, whereas low temperatures compromise the mobilization of reserves.

Index terms:
germination ecophysiology; reserve compounds; seed biochemistry; semiarid; thermal stress