Morfologia, anatomia, histoquímica e aspectos fisiológicos da lâmina foliar de espécies de Clusia (Clusiaceae)

Abstract

The leaf lamina anatomy of 14 Clusia species was studied. For most of the species the analysis also included morphological, histochemical, micromorphological and photosynthetic aspects. The leaves of C. criuva were processed to the aspects above and besides, the responses presented by these leaves to changes in light availability were observed in structure, photosyntesis and chemical composition. The samples were collected in Atlantic forest (Clusia aemygdioi, C. arrudae, C. intermedia, C. marizii e C.spiritu-sanctensis), in Restinga (C. fluminensis, C. hilariana, C. lanceolata e C. parviflora), in a Cerrado-gallery forest (C. burchellii, C. criuva, C. gardneri e C. nemorosa) and in Amazon forest (C. insignis). The leaf lamina shapes vary from obovate to elliptic, the margin type is entire, the base is a little asymmetrical and decurrent, the position of the petiolar attachment is marginal, the leaves are pinnate, camptodromous, weak brochidodromous, the primary vein is prominent, the secondary vein spacing is uniform, there are strong intersecondaries, areoles are poorly developed by the third and fourth order venational, the marginal ultimate venation is compound by a fimbrial vein. The main differences between the transversal sections are number of mesophyll celular layers, the primary vein thickness and shape, the cuticle thickness and ornamentation, number of druse crystals, the spongy parenchyma intercelular space proportions, number of vascular bundles in the primary vein, presence of sclerenchymatic tissue under the epidermis only in C. burchellii. The histochemical analysis showed lipophilic material inside the secretory ducts; the soluble carbohydrates concentration and location are distinct between the species; starch occurs mainly around the vasculat cylinder of the primary vein; phenolic material, and also tanin, were observed in almost all leaf lamina tissues. The stomata occur only in the abaxial surface, they are paracytic with kidney-shaped guard cells, in a irregular distribution, wiht distinct frequency and shapes from circular to elliptic. There is an inverse proportion between stomata frequency and length, this relation is independent of the species or the kind of environment. The epicuticular wax depositions are distinct between the species, as well as the thickness and orientation of the celulosic fibrils in the subsidiary cell walls and the thickness of the guard cell walls. The species anatomy characteristics vary according to the type of photosynthetic metabolism - C3, C3/CAM and CAM, the mesophyll is thicker in CAM species. The changes in light availability can alter C. criuva leaf features related to photosynthesis, leaf specific area, leaf thickness, alterations in th photosynthetic tissues proportion with reference to those non- photosynthetic, carbohydrates and clorophyll contents.