p. 41115 Seed Dormancy, Germination, and Seedling Establishment
- Lincoln Taiz, Lincoln TaizUniversity of California, Santa Cruz
- Eduardo Zeiger, Eduardo ZeigerUniversity of California, Los Angeles
- Ian Max MøllerIan Max MøllerAarhus University, Denmark
- , and Angus MurphyAngus MurphyUniversity of Maryland
Abstract
This chapter evaluates the processes of seed germination, hypocotyl and coleoptile growth, and seedling establishment. The seed tissues surrounding the embryo form a barrier that protects the embryo from the environment. In addition, the seed tissues provide stored foods that nourish the embryo throughout embryogenesis and early seedling development. Because germination is tightly coupled to the mobilization of these food reserves, the chapter begins with a description of seed structure and composition. It then considers various types of seed dormancy, which in some cases must be overcome before germination can take place. The chapter also discusses the mobilization of stored food reserves in different types of seeds, as well as the role of hormones in coordinating the processes of seedling growth and food mobilization. Finally, it looks at phototropism and gravitropism, the processes by which plants orient themselves to light and gravity.
