Potencial fisiológico de sementes de Mimosa bimucronata (DC) O. Kuntze obtidas de diferentes localidades sob temperaturas

Abstract

Maricá (Mimosa bimucronata (DC) O. Kuntze.) is a medium-sized tree species belonging to the Mimosaceae family (Leguminosae-Mimosoideae) that has wood, ecological, phytotherapeutic potential and ornamental value. It has rapid growth and is widely used in the restoration of degraded areas. It is assumed that this species has different ecotypes and adaptations to different climatic regions, since it is naturally distributed in the Northeast, South and Southeast regions of Brazil, being particularly frequent in the states of Pernambuco, Alagoas and Paraná. Based on this, this work aimed to study the influence of different locations and temperature regimes on the physiological potential of M. bimucronata seeds. The experiment was conducted at the Plant Propagation Laboratory of the Engineering and Agricultural Sciences Campus – UFAL. To study the effect of seed origin, two seed lots collected from forest fragments were used, one from the state of Pernambuco, in the municipality of Garanhuns (8o 53 '25 "S, 36o 29' 34" W, and 842 m from altitude), and another one from Alagoas, in the municipality of Anadia (9o 41 ′ 6 ′′ S and 36o 18 ′ 24 ′′ W, and 163 m of altitude). To study the effect of temperature on germination, the seeds were subjected to constant temperatures of 25 and 30oC, and alternating at 20-30oC. The parameters evaluated were: water content, weight of a thousand seeds, first count, germination and germination speed index, length and dry mass of seedlings. The experimental design used was completely randomized (DIC), with four replications of 25 seeds, the treatments were distributed in a 3 x 2 factorial scheme (three temperatures and two locations). The data were submitted to analysis of variance (ANAVA) and the means compared by the Tukey test at 5% probability. The analyzes were performed with the aid of the SISVAR 5.6 software. The analyzes were performed with the aid of the SISVAR 5.6 software. For the evaluation of germination and vigor of seeds from Pernambuco it is recommended to use a constant temperature of 30oC and for Alagoas, a temperature of 30oC constant, alternating at 20-30oC is suggested.