Morfologia polínica de espécies frutíferas nativas da Amazônia

Abstract

Brazil is home to approximately 250 species of native fruit plants not yet fully known and studied. Therefore, using pollen morphology as a resource in identifying flora, especially in the Amazon, known for its large extension, is essential. Thus, the main objective of this work was to characterize the pollen morphology of native Amazonian fruit species. We studied, palynologically, 30 species belonging to 13 families: Annonaceae, Arecaceae, Chrysobalanaceae, Clusiaceae, Fabaceae, Lecythidaceae, Malpighiaceae, Malvaceae, Melastomataceae, Myrtaceae, Sapindaceae, Solanaceae and Urticaceae. The material used was obtained from exsiccates deposited in INPA and HSTM herbaria. The pollen grains were treated through acetolysis, with at least four slides being prepared for each species. The fixation and assembly of the pollen grains was done in glycerin gelatin and the slides were sealed with paraffin. The analysis was performed under light microscopy and the pollen grains were described as to pollen unit, size, scope, shape, number and type of openings and ornamentation. For each species, characteristics such as habit and height, habitat, geographic distribution in Brazil and conservation status were also studied. The pollen grains ranged from small to very large, most being medium; Prolate-spheroidal and subprolate form predominant in most species, oblate in all Sapindaceae and most Myrtaceae; most of the pollen grains had a triangular to subtriangular scope. Polyads, tetrads, inarperturated, colpated and colporated monads and, for most grains, openings, 3-colporate and reticulated sexin were observed. With respect to species threatened with extinction, most did not present a degree of threat. In this study, morphological characters of the pollen grains of these fruit species were observed, which will greatly contribute as subsidies for palynological research in the Amazon.