Fertilization and seed formation are two critical processes in the reproductive cycle of plants. Fertilization is the fusion of male and female gametes to form a zygote, while seed formation is the process of developing a mature seed from the fertilized ovule.
During fertilization, pollen grains are transferred from the anther to the stigma of a flower, either by self-pollination or cross-pollination. Once the pollen grain reaches the stigma, it forms a pollen tube that grows through the style and reaches the ovary, where the male gamete is released and fertilizes the female gamete to form a zygote. The zygote then undergoes several rounds of mitotic division to form an embryo, which develops into the seed.
The ovule, which contains the female gamete, undergoes several changes during seed formation. The fertilized ovule develops into a seed coat, which protects the developing embryo. The endosperm, a nutritive tissue that surrounds the embryo, provides nutrients to the developing embryo. In some plants, the endosperm is absorbed by the embryo during seed development, while in others, it persists as a separate tissue in the mature seed.
Seed development is regulated by various hormones, including auxins, cytokinins, gibberellins, and abscisic acid. These hormones influence the growth and development of the embryo, endosperm, and seed coat. Environmental factors, such as temperature and light, can also affect seed development.
Seed dispersal is another critical aspect of reproduction in plants. Seeds can be dispersed by various mechanisms, including wind, water, animals, and self-dispersal. This dispersal helps plants colonize new habitats and ensures the survival of the species.
In conclusion, fertilization and seed formation are essential processes in the reproductive cycle of plants. The development of a mature seed from a fertilized ovule requires the coordination of various cellular and molecular processes, including the synthesis and regulation of hormones and the interaction of the developing embryo with the surrounding tissues. Seed dispersal ensures the survival and spread of the plant species.