Germination of aspidosperma discolor a. Dc. Under Different light and Temperature Conditions

Abstract

Theoretical framework: Among the genera of the Apocynaceae family found in Brazil, Aspidosperma is among the most important, because of its high medicinal and economic value. Objective: The objective of this work was to evaluate the effects of white, far-red, and red light, and the absence of light; as well as the effects of constant temperatures of 25 ºC, 30 ºC and 35 ºC, on seed germination behavior of Aspidosperma discolor A. DC. Method: The material was collected in Atlantic Forest fragments. The germination percentage, speed index, average time and average seed germination speed were evaluated. A completely randomized design was used, and the means were compared by the Tukey test at 95% probability. A 4 x 2 factorial arrangement was used for the evaluation of the light regime (four light regimes and two origins); and for the thermal influence, a 3 x 2 arrangement (three temperature levels and two origins) was employed. Each test had five repetitions with 20 seeds. Results: The results showed that the seeds of both origins presented preferential or neutral photoblastic behavior, with better germination performance at 25 °C. However, they had total germination inhibition when exposed to 35 ºC.