Bertholletia excelsa SEEDS IN THE CERRADO-AMAZON TRANSITION REGION: MORPHOMETRY, COLORIMETRY, VIABILITY AND GERMINATION

Abstract

This study aimed to describe the morphometric characteristics of fruits and seeds, and to evaluate the viability and germination of B. excelsa seeds stored under litter under microenvironmental conditions of their natural habitat in the Cerrado-Brazilian Amazon transition. The morphometric characterization included measurements of diameters and latitudinal and longitudinal circumferences of the fruits; exocarp and mesocarp thickness, weight of fruits and seeds per fruit, number of seeds per fruit, thickness, width and length of seeds. Seed moisture was obtained by the ratio between masses. The colorimetric characterization occurred in the mesocarp, external and internal tegument and in the internal part of the seed. Seed viability was evaluated by the tetrazolium test and germination with degummed and intact seeds. Morphometric variability of fruits and seeds of B. excelsa was observed regardless of humidity. The color of the fruit and the outer seed coat changed color with the reduction of relative air humidity. Variations in the relative humidity of the air during the storage period influenced the significant reduction of 45.31% in the water content of the seeds and compromised the physiological quality, reducing the viability and germination capacity of the seeds. The seeds of B. excelsa are sensitive to variations in humidity. The storage of seeds inside the fruit under the litter under microenvironmental conditions of their natural habitat for up to 96 days with average relative humidity above 65%, guarantees the maintenance of seed moisture above the critical humidity of 30%. Viable seeds with germination power have a water content above 45%.