Floral Development, Sporogenesis, and Embryology in the Avocado, Persea americana

Abstract

Flower parts develop in acropetal order. The ovule is anatropous and has 2 integuments. A normal type of embryo-sac development results in an 8-nucleate megagame-tophyte. Microsporogenesis gives rise to the spherical pollen grains which have short conical spines. The endosperm apparent- ly results from triple fusion. It consists of a cellular tissue with large, conspicuous nuclei. No suspensor is formed. Differentiation of the cotyledons begins when the proembryo attains a diameter of 0.2-0.3 mm.