Abstract:Embryo development in Coix lacryma-jobi is classified into the following stages: proembryo before club-shaped, club-shaped, coleoptilar, I-leafed, 2-1eared, 3-1eared, 4-1eared, 5-leafed and 6-leafed (mature embryo). The 3-, 4-, 5-leafed embryos have 1, 2 and 3 adventitious roots (seminal roots) respectively, and the matrue also has 3. These seminal roots are arranged in a longitudinal row parallelling with the radicle. The storage reserves first deposit in the scutellar cells. 9 days after anthesis (l-leafed stage), the starch grains are accumulated in cells of scutellum, coleoptile and mesocotyle. When the embryo matures, starch grains are deposited throughout its cells. The increase in size and amount of starch grains correlates with the initiation and growth order of the embryonic organs. But the amount in the scutellar cells decreases from later to mature stage. 10 days after anthesis (2-leafed stage), protein bodies containing crystals, of protein and phytin are present in the scutellar cells. They subsequently become larger and abundant druses. At the same time some protein bodies without crystals are also formed. Later, the protein bodies containing crystals disappear, while those without crystals increase until the embryo matures. 13 days after anthesis (3- leafed stage) protein bodlies are formed in the upper coleoptile cells. Protein bodies are rich in the cells of mature embryo, but the earlier the organ of embryo occurs, the more and the larger protein bodies it contains. 10 days after anthesis, lipid bodies appear in the scutellar cells and increase in size and quantity rapidly as the embryo develops. The correlation of the length of caryopsis and scutellum with embryo development is also observed.