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The seed coat forms from the two integuments or outer layers of cells of the ovule, which derive from tissue from the mother plant, the inner integument forms the tegmen and the outer forms the testa. (The seed coats of some monocotyledon plants, such as the grasses, are not distinct structures, but are fused with the fruit wall to form a ...
No endosperm or seed coat is formed around a somatic embryo. Applications of this process include: clonal propagation of genetically uniform plant material; elimination of viruses; provision of source tissue for genetic transformation; generation of whole plants from single cells called protoplasts; development of synthetic seed technology.
Somatic embryos are formed from plant cells that are not normally involved in the development of embryos, i.e. ordinary plant tissue. No endosperm or seed coat is formed around a somatic embryo. Cells derived from competent source tissue are cultured to form an undifferentiated mass of cells called a callus.
Dry fruits depend more on physical forces, like wind and water. Dry fruits' seeds can also perform pod shattering, which involve the seed being ejected from the seed coat by shattering it. Some dry fruits are able to perform seed pod explosions, such as wisteria, resulting the seed to be dispersed over long distances. Like fleshy fruits, dry ...
Starting from a plant which disperses by spores, highly complex changes are needed to produce seeds. The sporophyte has two kinds of spore-forming organs or sporangia. One kind, the megasporangium, produces only a single large spore, a megaspore. This sporangium is surrounded by sheathing layers or integuments which form the seed coat.
Scarification is often done mechanically, thermally, and chemically. The seeds of many plant species are often impervious to water and gases, thus preventing or delaying germination. Any process designed to make the testa (seed coat) more permeable to water and gases is known as scarification.
In the caryopsis, the thin fruit wall is fused to the seed coat. Therefore, the nutritious part of the grain is the seed and its endosperm. In some cases (e.g. wheat, rice) the endosperm is selectively retained in food processing (commonly called white flour), and the embryo and seed coat removed. The processed grain has a lower quality of ...
The cotyledons open upon contact with light (splitting the seed coat open, if still present) and become green, forming the first photosynthetic organs of the young plant. Until this stage, the seedling lives off the energy reserves stored in the seed.