Embryo and endosperm development in Pitcairnia encholirioides (Pitcairnioideae – Bromeliaceae): An endangered species of the Atlantic Forest

Abstract

Pitcairnia encholirioides is a threatened species endemic to the inselbergs of the Atlantic Forest. The study of the embryogenesis and endospermogenesis of Pitcairnia encholirioides aims to the establish guidelines for its in vitro propagation. Using anatomical analysis, samples of flowers in anthesis and fruits at different developmental stages were analysed. In the results was observed the first division of the sporophytic zygote occurs in the transverse plane and originates the apical and basal cells, forming a uninodal embryo through Asterad-type embryogenesis. Endosperm formation begins with the formation of free nuclei, which undergo centripetal cellularization, beginning in the chalazal domain, characterizing this endosperm as the coenocytic/multicellular type. The differentiation of the aleurone layer occurs at the end of this process. The relationship between fruit maturation and embryo/endosperm developmental stages was established, thus setting forth guidelines for the development of in vitro culture protocols aimed at the conservation of P. encholirioides, an endangered Bromeliad species of the Atlantic Forest.