Water relation parameters in conifer embryos: methods and results.

Water plays a crucial role in processes such as fertilization, cell metabolism, and the development and growth of organisms. Maturation and germination of seeds are no exception. As predicted by Walbot (1978, see Bradford (1994) for a complete review), water governs and controls embryo development and, as pointed out by Adams and Rinne (1980), the absence of water serves as a switch for the embryo to go from a maturation programme to a germination one. This is true for both angiosperm (Johnson et al., 1997) and conifer seeds.