Types of germination epigeal and hypogeal
Germination refers to the process in which a seed begins to grow into a new plant. There are two main types of germination: epigeal and hypogeal.
1. Epigeal germination: In this type, the cotyledons, which are the embryonic leaves of the seed, emerge above the soil level. The epicotyl, the part of the embryo above the cotyledons, elongates and pushes the cotyledons and the plumule (the embryonic shoot) above the ground. Examples of plants that exhibit epigeal germination include bean, pumpkin, and sunflower.
2. Hypogeal germination: In this type, the cotyledons remain below the soil surface while the epicotyl elongates and brings the plumule above the ground. The cotyledons usually remain enlarged and serve as storage organs for the developing seedling. Examples of plants that exhibit hypogeal germination include peas, peanuts, and maize.
Both types of germination involve the emergence of the radicle (the embryonic root) first, which anchors the young plant into the soil and absorbs water and nutrients. After germination, the seedling continues to grow, developing leaves, stems, and roots.