Dormancy is modulated by seed structures in palms of the cerrado biome

Abstract

The aim of the present study was to evaluate the influence of the seed structures on the dormancy of the palms Attalea vitrivir Zona, Butia capitata (Mart.) Becc. and Acrocomia aculeata (Jacq.) Lodd. ex Mart., which are found in the cerrado biome (Brazilian savanna). The effects of seed structures on the imbibition and effects of the operculum on germination were evaluated. The effects of the collection area on the seed biometric characteristics and influence of the embryo mass and length on their germination capacity and vigour were also evaluated. The operculum was anatomically characterised, and the effects of the operculum thickness on seed germination were evaluated. The seed structures partially restricted water absorption by the embryos, but this did not affect germination; however, removing the operculum promoted germination. The mass of A. vitrivir and A. aculeata embryos positively influenced their germination capacity and vigour, and the thicknesses of the opercular seed coat and operculum negatively controlled the germination capacity of B. capitata. The greater thickness and rigidity of the operculum of A. aculeata increased the intensity of seed dormancy and possibly contributed to the wider distribution pattern of this species. The interaction between the embryo and operculum structures modulate the dormancy and possibly influence the distribution patterns of the palms in the cerrado biome.