Seed Structure and Histochemistry of Prosopis velutina (Leguminosae)

Abstract

Structure and histochemistry of mature seeds of Prosopis velutina were studied by light microscopy, coupled with histochemistry and proteolytic enzyme digestions, to identify structure and to localize storage components in the embryo. The testa was typical of leguminous plants; it consisted of cuticle, palisade layer, osteosclereids, and macrosclereids and was linked to the pods by a vascular supply. Like other members of the Mimosoideae subclass of legumes, the testa had a pleurogram, and the seed was albuminous. Cotyledons had two to three rows of palisade parenchyma on the adaxial side and more regular-shaped to slightly elongated parenchyma in the center extending to the abaxial side. Histochemistry showed that embryo cells lacked starch and contained numerous protein bodies. All tissues except the radicle, which was devoid of visible storage reserves, contained protein bodies as the most prominent storage reserve. Protein bodies stained moderately with periodate-Schiff's reagent, indicating a glycoprotein complex. Globoids, inclusions containing a phytin complex, were localized in several protein bodies, notably those in the center of the cotyledons and the cortex of the epicotyl-hypocotyl region.