Write a note on the development of endosperm. Mention the types with examples?
Development of endosperm: Endosperm develops after double fertilisation in angiosperms. It is triploid and develops from the primary endosperm nucleus. In angiosperms three types of endosperm development are observed: 1. Nuclear endosperm. In nuclear endosperm development, the nucleus divides by free nuclear division, there is the appearance of the central vacuole, all the nuclei are pushed towards periphery then starts cytokinesis and results in the formation of cells but in coconut, vacuole persists which is filled with fluid. 2. Cellular endosperm. In cellular endosperm, each and every division is followed by cytokinesis, so endosperm is cellular from the very beginning, e.g. Datura, Petunia. 3. Helobial endosperm. It is intermediate between cellular and nuclear endosperm. The first division is followed by cytokinesis to form two unequal cells, micropylar cell and chalazal cell. Further divisions in each cell are free nuclear divisions. This type of endosperm is found in order Helobiales.
