Moraceae Gaudich. de Viçosa, Minas Gerais, Brasil: florística e anatomia foliar de Ficus mexiae Standl

• Autor(a) principal: Souza, Pedro Paulo de
• Data de Publicação: 2009
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2506
• topic: Florística; Moraceae; Anatomia; Floristics; Moraceae; Anatomy; CNPQ::CIENCIAS BIOLOGICAS::BOTANICA

The present work consists of the floristic study of Moraceae species in Viçosa, of the leaf anatomy, and the histochemical characterization of Ficus mexiae Standl., comparing with the anatomic data in the literature about F. enormis (Miq.) Miq., a species that is similar to F. mexiae. Viçosa is located in the southeastern Brazil, in the state of Minas Gerais, in Zona da Mata, occupying an area of 300 km2, composing the microregion of Viçosa. The vegetation is composed of Semideciduous Tropical Forest, distributed as small forest fragments confined on the top of the hills and in lands with great slope. Samples were collected every fifteen days from January, 2007 to October, 2008. All the collect material was herbalized following the usual techniques and incorporated to the stacks of the VIC herbarium of the Vegetal biology Department of the Federal University of Viçosa, and duplicates were sent to the R, RB and GFJB herbaria. Specialized literature, reference to the herbaria, and visit to specialists were used in the species identification. Thirty-one species were identified among native and exotic, inserted in the Moroideae and Cecropioideae subfamilies, gathering 12 genera. Moroideae was represented by 25 species: Ficus 15spp, Brosimum and Sorocea 2spp. and Artocarpus, Clarisia, Dorstenia, Helicostylis, Maclura and Morus represented by one species each. Cecropioideae was represented by 6 species: Cecropia 3spp., Coussapoa 2 spp. and Pourouma 1sp. The majority of species presented arboreal habit, Ficus e Coussapoa can present hemiepífitico habit in the inicial phase, Ficus pumila L presents climbing habit, and Dorstenia is the only genus that has herbaceous habit. F. mariae C.C. Berg, Emygdio e Carauta, F. obtusiuscula (Miq.) Miq., F. organensis (Miq.) Miq. e F. trigona L.f. represent four new quotations of occurrence to the municipality. Brosimum glaziovii e Dorstenia bonijesu are endangered (EN), whereas Ficus mexiae, Coussapoa floccosa, Sorocea guilleminiana e S. bonplandii are in the vulnerable class (VU) according to the IUCN classification. Besides descriptions, botanical illustrations, and conservation class, keys to the determination of the species are presented. To the anatomic characterization of F. mexiae, samples of leaves were fixed in FAA50 for 24 hours and in formalin 4%, in ferrous sulfate 10% for 48 hours and stored in ethanol 70% to the structural characterization. Samples of the leaf blade and petiole, in the proximal, median and distal regions, were dehydrated in ethylic series, included in methacrylate, 5-µm cuts were obtained in rotatory microtome, were stained with toluidine blue and assembled under cover slip with synthetic resin. The diafanization and the dissociation of the epidermis were carried out in order to study the leaf surface. Fresh samples from the median region of petiole and the leaf blade cut with a table microtome and exposed to several dyes and reagents were used to the histochemical tests. The samples destined for the scanning electron microscopy were fixed in FAA50 and exposed to the usual processing used to this kind of analysis. The F. mexiae leaf is hypostomatic with a uni or biseriate epidermis, covered by a thick cuticle, tector or glandular trichomes, and anomacytic stomata. Mesophyll dorsiventral with biseriate palisade parenchyma and lacunary parenchyma of miceliform aspect. Litocysts disposed on both faces and idioblasts and laticiphers distributed among the veins parenchyma cells, of the petiole and the vascular bundle sheath. Evident boundary curvature with crystals. Reniform petiole and collateral vascular system. The framework tissue is formed by ring collenchyma. The histochemical analysis indicated the presence of phenolic compounds, tannins, and alkaloids in laticiphers and idioblasts, and lipids, terpenes and rubber particles were found only in the laticiphers. A miceliform aspect of the lacunary parenchyma and ring collenchyma represent the main anatomic characteristics that distinguish F. mexiae from F. enormis.