Germination, dormancy and morphology of the seeds of herbaceous ornamental plants

• Published in: Seed Science and Technology (Netherlands) Vol. 8; no. 4
• Main Author: Atwater, B.R. (Ransom Seed Lab., Santa Barbara, Cal. (USA))
• Format: Publication
• Language: English
• Published: 1980

Eight basic forms of seed structure are described. The seeds of species within each form have been found to have similar dormancy and germination patterns. Seed with rudimentary and linear embryos require time for further maturation of the embryo before germination. Miniature seeds require light at the beginning of the germination period. Seeds with peripheral embryos are protected by inhibitors in multiple seed coverings which need to be removed or leached before germination. Non-endospermic seeds or seeds with residual endosperm have mature embryos which are ready to grow but growth is blocked by their seed coverings. Hard seed coats which restrict the imbibition of water require mechanical or chemical abrasion or a release through the hilum, chalaza or strophiole. Seeds having a mucilaginous exudation exclude oxygen and may require light, low temperature or the addition of gibberellic acid. Seeds with multi-layered woody and fibrous seed coats are semi-permeable, allowing water entry but blocking oxygen and retaining strong inhibitors. Extracted embryos grow readily. Various permeability aids are necessary including temperature alternation, KNO(,2), light and abrasion. An understanding of these structural blocks to germination and the modifying effects of environment is directive in establishing methods for germinating flower seeds.