In details explain hypogeal germination
Hypogeal germination is a type of seed germination that occurs beneath the soil surface. During this process, the cotyledons, which are the embryonic leaves of the seed, remain submerged in the soil while the shoot and root emerge above ground. This type of germination can be observed in many plants, including beans, peas, peanuts, and sunflowers.
To understand the details of hypogeal germination, we need to delve into the steps involved:
1. Imbibition: The first step of germination is the absorption of water by the seed. The seed takes in water to activate metabolic processes and soften the seed coat.
2. Activation of enzymes: Enzymes within the seed are activated by the presence of water. These enzymes break down stored nutrients, such as starch and proteins, into simpler forms that can be used by the developing plant.
3. Radicle emergence: The radicle is the embryonic root of the plant. It grows downwards into the soil, anchoring the plant and absorbing water and nutrients.
4. Shoot emergence: After the radicle has established itself, the shoot starts to grow upwards. In hypogeal germination, the cotyledons - which are stored with nutrients - remain below the soil surface.
5. Hypocotyl elongation: The hypocotyl is the region of the plant between the radicle and the cotyledons. It elongates and pushes the plant upwards, allowing it to emerge from the soil.
6. Cotyledon development: While the shoot is growing above ground, the cotyledons in hypogeal germination stay below the surface. They continue to provide nutrients to the growing plant until the true leaves develop.
One way to observe and study hypogeal germination is by setting up a simple experiment. You can select seeds of a plant that exhibits hypogeal germination (such as a bean or pea) and plant them in a pot with soil. Ensure that the seeds are covered with a layer of soil. Keep the pot in a suitable environment, providing adequate water and light.
Over time, you will be able to witness the radicle emerging from the seed and growing downwards into the soil. The shoot will start to emerge as well, with the cotyledons remaining below the surface. By closely observing the development of the plant, you can get a detailed understanding of hypogeal germination.