Effect of drying and soaking fruits and seeds on germination of macaw palm (Acrocomia aculeata [Jacq.] Loddiges ex MART.)

Abstract

This study evaluated mechanisms of the dehydration and rehydration of fruits and seeds on the resulting embryo viability of the macaw palm, Acrocomia aculeata (Jacq.) Loddiges ex Mart. Dehydration was performed in a forced-air oven at 37 ± 2°C for 0, 3, 6, 9, 12 or 15 days, and after these periods, the embryo viability was evaluated by the tetrazolium test. The effect of hydration on the germination percentage and velocity index was evaluated by the imbibition of seeds with distilled water in a germinator at 30 ± 2°C for 0, 2, 4, 6, 8 or 10 days. The seeds were then treated with fungicide and maintained in a Mangelsdorf germinator at 30 ± 2°C. Drying caused a progressive water loss in the fruits and facilitated the extraction of the seeds. Fruits subjected to drying for up to nine days had no loss of vigor; however, after dehydration for 15 days, a loss in seed viability was observed. Simple linear regression estimated the seed water content based on the fruit water content. Seed imbibition in distilled water favored an increase in dead by fungally contaminated seeds.