TY - BOOK AU - Mooney,P.A. AU - Van Staden ,J. TI - Induction of embryogenesis in callus from immature embryos of Persea americana KW - PERSEA AMERICANA N2 - Both the external morphology and internal anatomy of developing somatic embryoids and plantlets of Persea americana (avocados)were studied. The embryogenic callus, which is embryoidal in origin, was made up of normal parenchymatous tissue toward the centre of a clump of cells and numerous proembryoidal cells on the periphery of the callus mass. Embryogenesis appeared to begin in single cells on the periphery of the callus and from cells on the surface of existing proembryoids. Embryo initials could be recognised by their conspicuous starch contents and by their thickened walls, which lack plasmodesmata. Cell divisions occurred in cells with thickened walls to give rise to globular proembryoids. Proembryoids developed into heart-shaped, torpedo-shaped and cotyledonary embryoids and finally into complete plantlets UR - https://drive.google.com/file/d/1S7f1FbcbjMbvM_RSrrC30qAs-tjTgaa-/view?usp=drivesdk ER -