Extração, avaliação da viabilidade e armazenamento de pólen de pequi

Abstract

The pequi (Caryocar brasiliense Cambess.) is a native species of the Brazilian Cerrado with significant ecological and socioeconomic importance, whose use in breeding programs is associated with pollen viability. This study aimed to establish and optimize protocols for pollen extraction, in vitro germination, and storage of this species. Three extraction methods were compared (anthers removed with scissors, anthers manually detached, and natural release by immersion of floral buds), five culture media: (A) 10% sucrose; (B) 15% sucrose; (C) 20% sucrose; (D) 10% sucrose + 0.65 mM boric acid; and (E) 10% sucrose + 1.3 mM boric acid; and three storage conditions (room temperature ~25 °C, refrigeration ~8 °C, and freezing ~−15 °C), with viability evaluated over 131 days. Immersion of floral buds was the most efficient extraction method, providing higher pollen yield and purity. The medium containing 10% sucrose and 1.3 mM boric acid showed the highest germination rate (67.28%). Regarding storage, room temperature led to a marked decline in viability, with total loss after approximately 42 days, whereas refrigerated conditions showed greater stability throughout the experimental period. No statistically significant differences were observed between refrigeration and freezing (p ≥ 0.05), although refrigeration exhibited more stable behavior. The results indicate that the combination of floral bud immersion for extraction, germination in a medium containing 10% sucrose and 1.3 mM boric acid, and storage under refrigeration constitutes an efficient strategy for managing C. brasiliense pollen, with potential applications in conservation and genetic improvement.