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Seed ontogeny in Tabebuia ochracea (Cham.) Standl. (Bignoniaceae)

The present work describes seed ontogeny in T. ochracea through histological analysis with special reference to the endospermogenesis. The ovule is anatropous, unitegmic and tenuinucelate; hypostase, nutrient passage route and endothelium are present. The endosperm is cellular with posterior development of Catalpa type. The chalazal haustorium of endosperm is primary, bicellular and it is totally degenerated during seed maturity; on the contrary the micropylar one is secondary, multicellular, differentiates latter, and remains active until the seed maturity.A latter differentiated endosperm was observed forming, together with the endothelium, a membranaceous envelope of the embryos. The endospermogenesis are in accord with previous results from other species of Tabebuia. Furthermore, the micropylar haustorium diferentiation and the membranaceous envelope origin were elucidated, the latter probably is the same in other species that present this structure.

Bignoniaceae; endosperm; ontogeny; seed; Tabebuia ochracea


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