Erythrina velutina Willd. (Fabaceae) is a Brazilian native tree with economic,

ecological and social potential. The aim of this study was to evaluate isoenzyme activity and

changes in DNA integrity during germination of E. velutina at different temperatures. The

seeds were placed to germinate at 5, 15, 25, 35 and 45 °C, evaluating isoenzyme activity and

degradation of the DNA during germination. Isoenzyme expression occurs differently for

seed germination under different temperatures, with varied expression between seedlings

and cotyledons. The esterase enzyme was more sensitive to express the response of the E.

velutina germination seeds at different temperatures. DNA repair is more efficient during

the germination of E. velutina seeds when submitted to a temperature of up to 25 °C, with

damage to the genetic apparatus with an increase higher than this temperature.