Caracterização morfoanatomica e fisiológica de sementes e plântulas de Jatropha curcas L. (Euphorbiaceae)

Abstract

Jatropha curcas L. is a popularly known species found in almost all intertropical regions of the planet. The oil present in its seeds have medicinal properties and economic importance. The species is currently indicated as a promising source of raw material for biofuel production. Thus, the objectives of this study were to characterize morphologically seeds and seedlings of Jatropha curcas L., and to perform studies on tissue anatomy linking the seeds development to the seeds imbibition's stages. Internal and external details were found on the morphological analysis of the seeds and seedlings. Regarding the study of the germination stages, we conducted a test to evaluate the seeds' behavior during imbibition. For the anatomical analysis, permanent slides were prepared with section's tissues seeds after 0, 4, 24 and 72 hours of imbibition. The Jatropha curcas L. seeds are endospermatics, elliptical and anatropous with glabrous seed coat, presenting pores and fictions on its surface. The cotyledons are foliaceous, showing cordiform shape and trinervis ribbings. The germination is phanerocotylar epigeous. Anatomically the seeds are albuminous. The seed coat consists of parenchymatic and polygons cells with vacuoles with vascular beams and sclerified cells. The endosperm is composed of polyhedral cells rich in reserve substances, mainly lipids. During the germination phases, alterations were observed in the reserve substances concentration of the endosperm, as well as changes in the organization of the vascular beams gifts.