Anatomy of sugar apple (Annona squamosa L.) seeds (Annonaceae)

The sugar apple is of great economic importance to the country,

however, information on the anatomical and morphological

aspects of Annonaceae family seeds is limited to a few species

and the anatomical studies refer to very few seeds. Using histological

techniques and microscopy, Annona squamosa L. seeds

were studied with regard to their anatomical characteristics.

In general, they presented the typical anatomical patterns of

seeds of the Annonaceae family. The multilayered testa was

comprised of exo-, meso- and endotestas, with the presence

of longitudinal and oblique fibers. The embryo was small and

straight with moderately developed embryonic axis, rudimentary

plumule and flat and thin cotyledons, wherein one could

observe the procambium. In particular, the perichalaza was

observed in the medium longitudinal plane of the endotesta

with more than two rows of vascular tissue. The tegmen or inner

integument was collapsed. The micropylar plug was tapered,

woody and composed of transverse fibers; a fracture line was

also observed. The ruminate endosperm interfered with both

the inner and external integuments. Oleiferous idioblasts were

observed at the outer edges of the ruminations.