Some Aspects of the Developmental Anatomy of Arachis hypogaea L.

Abstract

Studies of the different stages of the embryo of Arachis hypogaea L. revealed that the root apex and cotyledons are initiated in the globular embryo. The root cap is formed in the heart-shaped embryo but it does not persist in the mature one, its place being occupied by cortical files. There is a common initiating region for the columella and provascular strands at the radicular apex. The cortical files “open out”, exhibit knee joints, and contribute secondary columella files. The radicular apex becomes distinct before the plumular apex. The protoderm of the “embryonic shoot apex” is not stable in the heart-shaped embryo but becomes stabilised in the later stages. The mature shoot apex exhibits four cytohistological zones. The floral anatomy shows some peculiar features like one staminal trace fusing with the trace of the standard petal, and the tendency for reduction in the androecium. The node is trilacunar. The nuclear endosperm is meagerly developed and has cytoplasmic nodules. A hypostase is also developed.