Uso das reservas seminais nas sementes e o efeito da poda no desenvolvimento inicial de mudas de Bertholletia Excelsa Bonpl

Abstract

The seed of the Amazon nut (Bertholletia excelsa) has a hypocotyl-type embryo, rich in nutritional and lipid reserves. Seedlings have bipolar germination, characterized by the emergence of the aerial part on the opposite side to the primary root. The reserve hypocotyl persists in the basal structure of plants, even after the establishment of the seedling, when it no longer depends on reserves for development. The type of seedling makes B. excelsa vulnerable to predation, as the hypocotyl rich in reserve attracts several wild animals, mainly rodents, which destroy the main axis of the plant in search of food. The Aruanã Agricultural Farm adopts aerial and root pruning with success in the production of chestnut seedlings. The present project aimed to provide technical-scientific foundations for the empirical methods applied. The study evaluated the depletion of seed lipid reserves in the development of B. excelsa seedlings, the effect of pruning on biomass production and the anatomy of the development of vascular bundles in the plant's basal structure (hypocotyl). Seeds (fruiting 2022) and seedlings aged one year (fruiting 2021) and two years old (fruiting 2020) from Aruanã Farm were evaluated and subjected to pruning, and control seedlings from the same fruiting were evaluated. The practice of pruning in seedlings increased the dry matter of the shoot and root axis by increasing the diameter, contributed to the more accelerated development of vascular tissues and delayed the consumption of lipid reserves during recovery from post-pruning damage, in addition to modifying the composition of fatty acids. Anatomical and metabolic changes increase the species' resistance in permanent plantings.