Morfoanatomia de frutos e sementes em Apocynaceae / Morphoanatomy of fruits and seeds in Apoctnaceae

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

This paper had as objective contribute for the knowledge of Apocynaceae by a morph-anatomic survey data from fruits and seeds from species of the family. On this study, 13 species present in Brazil and distributed in three of the five families currently described, were included. Flowers, fruits and seeds in many development levels were collected, fixed and submitted to anatomy usual techniques. In the first chapter Aspidosperma australe Müll. Arg., A. olivaceum Müll. Arg. and A. pyrifolium Mart. ripe fruits were studied. The fruits have uniseriate epicarp with thick cuticle, lenticels and periderm. Cover trichomes were found only in A. australe. The mesocarp presents fundamental parenchyma, laticifers, vascular bundles, sclereids and idioblasts with prismatic crystals. In A. pyrifolium, the sclereids are arranged in groups of a variety of cells and A. olivaceum has laticifers with parenchymatic sheath. All species have multiseriate endocarp but only in A. australe the cells are lignified. In the second chapter an ontogenetic study of the Allamanda blanchetii A. DC. and Allamanda schottii Pohl capsules was made. Despite the fact these capsules has been traditionally classified as loculicidal, on this paper it was verified that they are, really, septicidal bicarpelares capsules. The epicarp of both species is uniseriate and has thick-walled epidermal cells, thin cuticle and stomata. In the mesocarp we can observe collenchymatic hypodermis, sclereids ring, fundamental parenchyma, aerenchyma, vascular bundles, islands of phloem and laticifers. The endocarp of both species is formed by several layers of sclereids, which have crossed arrangement only in A. blanchetii. Dispite they present pericarp with many similarities, it was possible to see that only A. blanchetii has aerenchyma distributed throughout the mesocarp of the fruit and, so, this is a good characteristic to distinguish the species. In the third chapter an ontogenetic study of the Prestonia coalita (Vell.) Woodson (Apocynaceae) fruits was made. The fruit of P. coalita, previously called follicle, is a septicidal bicarpelar capsule, each valve provided by a single carpel. The epicarp, originated exclusively from the external epidermis of the ovary, is formed by one layer of epidermal cells with thick cuticle, stomata, lenticels and cover trichomes. The mesocarp is originated from the ovarian mesophyll and is made by collenchymatic cells, parenchyma cells, not-lignified fibers, bicolaterals vascular bundles, islands of phloem and laticifers. The endocarp is formed by a layer of sclereids and the dehiscence of the capsule occurs due to the rupture in the region of the leaves carpels union. In the fourth chapter ripe fruits of Blepharodon bicuspidatum E. Fourn., Oxypetalum appendiculatum Mart., O. balansae Malme and O. glaziovii (E. Fourn.) Fontella &Marquete, species of the subfamily Asclepiadoideae, were studied. The pericarp of all species is formed by a uniseriate epicarp covered by a thick cuticle, striated only at B. bicuspidatum. All the species have stomata, but cover trichome are present only at O. appendiculatum. The mesocarps of all species are very similar, because they are formed by fundamental parenchyma, fibers, laticifers vascular bundles, islands of phloem and aerenchyma. The fibers have thick walls and without lignin, flattened in O. glaziovii or rounded in other species. Idioblasts with crystals of the druse type are present only in the mesocarp of O. appendiculatum. All species have uni or bisseriate lignified endocarp. In the fifth chapter ripe seeds of Allamanda blanchetii A. DC., Malouetia arborea (Vell.) Miers, Mandevilla pohliana (Stadelm.) A. H. Gentry and Tabernaemontana arborea Rose were studied. All have single seed-coat, embryo and endosperm. The seeds are exotestals and in the testa cells are phenolic compounds. Only M. arborea presents multisseriate exotesta. In all species, the cotyledon is dorsiventral. The main store substances found were proteins, normally forming protein bodies, being detected in the cotyledon and endosperm of all studied species. Starch was detected only in the cotyledons and endosperm of M. arborea and the aril of T. arborea. Lipid bodies were also observed in T. arborea

ASSUNTO(S)

fuits sementes - anatomia plant anatomy frutas - anatomia seeds apocynaceae anatomia vegetal apocinaceas

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