Germination refers to a fundamental process in which we grow the sown plant seeds into younger plants or seedlings. On the basis of the growing conditions and the cotyledons' fate, there are two types of germination processes, as follows:
This article is essential for the Biology students to get a brief idea about germination, its types, and hypogeal germination. It covers all the fundamentals of the concepts and includes some FAQs related to the examinations to assure the students' best practice and understanding.
Define Hypogeal Germination –
A hypogeal germination is a form of seed germination that occurs mainly for both monocot and dicot seeds. The cotyledons stay inside the soil due to quicker growth and development in the epicotyl's length. Hypogeal germination is derived from an ancient Greek word, referring to the meaning 'below ground'. Here is a description of the hypogeal germination process:
Cotyledons – A significant part of the embryo of the seed stays under the soil.
Plumule – The rudimentary shoot tip that rises from the seed embryo grows above the ground.
Plumule rises and pushes itself upwards.
This process continues with epicotyl – the seed system that stays above the cotyledon and rapidly elongates its structure and shape.
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What is the Hypogeal Germination Process?
After the epicotyl's length grows and develops ultimately, it assumes a curved curvature, causing the plumule to rise above the soil surface and pushing the cotyledons to stay below the surface. In these types of germination, the plumule rapidly grows in length and then eventually ruptures the coleoptiles while undergoing further growths. The ruptured plumule then grows into radical, and the root system then replaces it. In this germination, the terminal part of epicotyls is curved for reducing damage to plumule by friction due to the soil particles.
Hypogeal Germination Seed Examples –
Here are some hypogeal germination examples:
Among the dicotyledons, pea, gram, and groundnut are some prominent examples.
In monocotyledons, maize, coconut, rice, and wheat are some common examples.
Pros and Cons, Related to Hypogeal Germination –
The benefit of hypogeal germination is that the plant or the seedlings are protected from early grazing in this process. In contrast, the disadvantage of hypogeal germination is that in this process, the plant cannot start synthesizing its food or photosynthesize until the true leaves appear entirely.
Key Points Necessary to Understand About Hypogeal Germination –
Hypogeal germination is among the prominent types of germination in which the seed leaves or cotyledons stay under the soil surface during the entire germination process.
In this, the terminal part of the epicotyl stays curved for reducing the damage to the plumule due to the friction from soil particles.
In hypogeal germination, hypocotyls do not elongate more. Instead of that, the epicotyl grows while keeping the plumule above the soil.
With the elongation of the epicotyls, the plumule emerges out of the seed coat in the process.
In this germination, the energy for growth is mainly derived from the endosperm.
Epicotyl is comparatively more extended in the plants, which show hypogeal germination.
Cotyledons do not appear as playing any significant role during photosynthesis.
Plumule does not always stay enclosed and protected by the cotyledons until it emerges out of the soil.
Mostly, the monocot seeds are the ones that show hypogeal germination prominently.
Hypogeal germination occurs in several plants, including maize, arum, water lily, gram, pea, and coconut.