Influence of light, temperature and humidity on substrate and osmoconditioning during the germination of Mimosa bimucronata (DC) O. Kuntze

Abstract

The maricá (Mimosa bimucronata (DC) O. Kuntze) is a forest species, belonging to the family Fabaceae, considered endemic to the Atlantic Forest biome. The present work aimed to study the germinative behavior of M. bimucronata seeds under different temperatures and light qualities, as well as to evaluate the effect of the amount of water (humidity) in the substrate and the osmoconditioning during germination. Thus, the experiment was performed using a completely randomized design. The treatments were distributed in a 4 × 4 factorial scheme (temperatures and light qualities), with 4 replicates of 25 seeds each. The means were compared by Tukey’s test at 5% probability. The volume of water and osmoconditioning of substrate was evaluated and data were subjected to regression analysis. The following variables were analyzed: first count of germinated seeds, germination, germination speed index, and electrical conductivity. The results revealed that seeds are neutral photoblasts, needing a constant temperature of 30 °C along with a white light for appropriate germination and vigor. Seeding on two sheets of paper towel moistened with water volume (mL) from 2.62 to 2.70 times was more suitable for conducting the germination test. The osmotic conditioning was inefficient in maintaining germination of these seeds