eChapter Name: Seed Physiology
9789390083121
eBook Name: METHODS AND TECHNIQUES IN PLANT PHYSIOLOGY
by A. Bhattacharya, Vijay Laxmi
Much of the success on modern agriculture dependson the availability of high quality seeds with good genetic potential and proven performance in germination, emergence, and vigorous Vegetative growth.
Seed: Seed is a fertilized mature ovule containing an embryonic axis (embryo), stored food material (endosperm) and a protective covering (seed coat or testa).
Seed structures: Living embryo, the most important part of seed, consists of two structures (i) embryonic axis and ( ii ) cotyledon(s). Theembryonic axis is composed of three parts namely
(i)radical (embryonic root), the hypocotyls (point of attachment of cotyledons) and (iii) plumule (theshootapex with the first true leaves). Thethree parts of embryonic axis are easy to identify in dicots, but in monocots (especially in the family Gramineae) their identification is difficult. In monocots, there is only one cotyledon, which is reduced and modifiedto form the scutellum. The basalsheath of cotyledon is elongated to take the shape of coleoptile,while in somecases (e.g., maize), the hypocotyls is modified to form mesocotyl. The base of hypocotyls sheathing the radical is termed as coleorhiza.
Seed development: Thereare manyvariations in the pattern of seeddevelopment when the entire plant kingdom is considered. However, the general processof This includes seed development is almost similar.