Morphology of the pericarp and seed of Tabebuia chrysotricha (Mart. ex DC.) Standl. (Bignoniaceae)

The morphology and anatomy of the fruit and seed of Tabebuia chrysotricha (Mart. ex DC.) Standl. (Bignoniaceae), a species typical of the Atlantic rainforest, is presented and discussed. The fruit was a loculicidal capsule, dehiscing through two slits, liberating a seminiferous column. The dehiscence process of the fruit involved separation tissue and two crossed sclerenchymatous mesocarpic layers (middle and subepidermic). The seed originated from an anatropous, unitegmic and tenuinucellate ovule. It was exotestal and presented polyembriony. The endothelium and endosperm were conserved in the mature seed and protected the embryo. Adventive embryos were made up of hypostase cells.

Regeneration of Bigleaf Magnolia by Somatic Embryogenesis

Bigleaf magnolia (Magnolia macrophylla Michx.) cultures were initiated from immature seeds on an induction medium containing 9.0 μm 2,4-D, 1.1μm BA, and 1 g casein hydrolysate/liter. After 2 months on induction medium, one culture produced adventive embryos. Clumps of embryos transferred to liquid induction medium proliferated as nodules, which grew in diameter, but failed to produce embryos while maintained in induction medium. Nodules transferred to basal medium produced clumps of somatic embryos, which continued to produce repetitive embryos with monthly transfer to fresh basal medium. Individual embryos transferred to basal medium lacking casein hydrolysate germinated and leaves expanded. Plantlets derived from these embryos were transferred to potting mix and acclimatized to greenhouse conditions. Chemical names used: (2,4-dichlorophenoxy)acetic acid (2,4-D); N -(phenylmethyl)-lH-purin-6-amine (BA).