Germination of Roystonea borinquena of Cook (Arecaceae) seeds

Abstract

This work aimed to study the effect of the temperature on the seed germination and to describe the morphology and germination process of disseminules (seeds with stucked endocarp) of R. borinquena species. The fruits were harvested and had their pulp (exocarp and mesocarp) removed and the disseminules were shade dried. The experimental design was entirely randomized and six treatments were performed (temperature conditions: constant at 25, 30 and 35°C; alternated at 25-35 and 20-30°C; and room temperature) with four replications with 25 disseminules per plot, placed in plastic boxes (gerbox) containing vermiculite. The germination rate and germination speed index were calculated, and the data were submitted to the variance analysis, and the means compared by the Tukey test. For the morphological studies, the external and internal sides of the disseminules, the embryo and the representative germination stages were sketched. The samples were fixed in FAA (formalin - acetic acid - ethyl alcohol). It was concluded that the highest germination rate and faster germination were at the constant temperature of 35°C and alternated of 25-35°C. The seeds are albuminous, with a hard endosperm that takes almost the entire interior of the disseminules; the embryo is lateral, peripheral and poorly differentiated; the germination is adjacent.