The seeds originate from the plant ovum, usually after fertilization. They are the first phase of the development of a new plant. Some seeds originate within the flowers that give rise to the fruits. In other plants that do not have flowers, the seeds are exposed in the growing branches that produce fertile leaves.
The seed is a plant embryo accompanied by a food store, protected by several layers of outer envelopes. Flowers appear in the reproductive phase of some plants. These are considered organs that own the fertile part of the plant.
It is just in the flowers where the spores or gametes are formed. There the fertilization takes place that leads to the formation of the embryo. In the latter is where the seed is latent.
When the fruit matures it releases the seeds, these when falling to the ground, germinate and form a new plant starting a new reproductive cycle. Each seed bears a fruit that germinating in the ground can develop a new plant.
The seeds are characterized by their hardness from their envelope. This lining is formed from covers, called integuments, that originally surround the ovule.
Once the ovule matures into a seed, that shell matures as well and can become a thin covering.
The seeds are produced in flowering plants, called angiosperms, and in gymnosperms. The seed is made up of the embryo, the seminal coat and the food store.
Process by which seeds originate
The seed as a reproductive unit is complex. To understand its formation, the life cycle of plants that takes place in flowers must be known.
Within these, sexual structures like the stamens and ovary do the work. For this, pollination must first occur. Pollen grains, male gametes, must travel through air, water or with the help of insects to the ovaries of plants.
When the pollen reaches the pistil, which is the female organ, it descends likewise towards the ovule. As in animals, this union, known as fertilization or fertilization, produces the zygote.
From that moment, the flower begins to lose part of its structure, while another part is transformed. This change accompanies the fertilization that ends up becoming the fruits that house the seeds.
The fruits and the seeds
The edible product of the fruits is known as fruit, which is nothing more than the fleshy covering that protects the seed, called the mesocarp.
In nature there are infinite variations with respect to the structure of the fruits and the dispersion mechanisms of the seeds. Therefore, not all flowers are the same.
For this reason, production in plants without flowers as obvious and showy as the most common ones can seem complicated. However, adaptation has made it possible to multiply the forms of reproduction according to their own conditions.
The seeds have also been the product of many studies and based on them, their production in agriculture has been controlled.
References
- De la cuadra, C. (1992). Germination, dormancy and dormancy of seeds. Recovered from mapama.gob.es
- The seeds. Digital library. Recovered from Bibliotecadigital.ilce.edu.m
- Megías, M.; Molist, P and Pombal, M. (2015) Plant organs SEED. Recovered from mmegias.webs.uvigo.es
- Royal Botanical Garden. (2010). Botany workshop: The fruits. Recovered from rjb.csic.es
- Unit 24: Fertilization and embryogenesis. (2013). Vascular Plant Morphology - Faculty of Agricultural Sciences. Recovered from biologia.edu.ar.