Difference between Epigeal and Hypogeal Seed Germination. The term germination designates the overall processes beginning with the imbibition of water by. The main difference between epigeal and hypogeal germination is that in epigeal germination, the cotyledons emerge out of the soil during. Hope you already know that what is cotyledon and how seeds germinate. Epigeal; In this type of germination, the seed /cotyledons emerge out of the soil or .
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In epigeal germination, the cotyledons emerge out of the soil while in hypogeal germination, the cotyledons remain inside the soil. The plumule is not visible so long as it is covered by the base of the cotyledon in the form of a sheath just above the radicle. The straight radicle comes out of the seed and fixes the seed to the soil with the secondary roots developing from the radicle.
Plants that show hypogeal germination need relatively little in the way of external nutrients to grow, therefore they are more frequent on nutrient-poor soils.
Difference Between Epigeal and Hypogeal Germination
The plumule within the germinatoin becomes exposed and soon grows into the aerial shoot Fig. Growth continues till the hypocotyl and radicle become several centimetres long more than 70 cm in Rhizophora. The grain imbibes water from moist soil. After emerging out of the soil, these cotyledons are called seed leaves, which become photosynthetic as well.
No photosynthesis takes place within the cotyledon. Among dicotyledons, gram, pea Fig. The second leaves derived from the plumule become true leaves.
The embryo penetrating the seed coat is the conclusion of the germination process. In addition to food storage, cotyledons undergo photosynthesis and produce food for the development of the embryo. Adventitious roots are formed from the lowermost nodes above the mesocotyl Fig. The radicle and seminal roots with two branches persist throughout the life of the plant. Here’s how it works: Normally, the cotyledon is fleshy, and contains many nutrients that are used for germination.
In seeds with epigeal germination, the cotyledons are brought above the soil due to elongation of the hypocotyl. This means the hypocotyl shows a greater elongation in epigeal germination while the hypocotyl is short in hypogeal germination. The radicle comes out and first penetrates the soil and forms root system by giving out secondary branches. Epigeal is also not the same as hypogeal germination; both epigeal and hypogeal plants will grow differently.
Epicotyl is short in plants that show epigeal germination while the epicotyl is long in plants that show hypogeal germination.
Difference Between Epigeal and Hypogeal Germination –
An example of a plant with epigeal germination is the common bean Phaseolus vulgaris. The cotyledons in epigeal germination turn green and undergo photosynthesis while the cotyledons in hypogeal germination do not undergo photosynthesis.
Plants that show hypogeal germination grow relatively slowly, especially in the first phase. Anybody can ask a question Anybody can answer The best answers are voted up and rise to the top. The hypocotyl part of the stem below the cotyledon elongates while the epicotyl part gdrmination the stem above the cotyledon stays the same length. The radicle fails to develop any further but several adventitious roots grow from the base of the plumule.
Epigeal germination implies that the cotyledons are pushed above ground. Inbotanist James A. Answer Now and help others. The seedling becomes established where the adventitious roots penetrate the soil Fig. The plumule soon forms the aerial shoot.
This protects the plumule. The opposite of epigeal is hypogeal underground germination. During germination the lower end of the embryo forms the cotyledon which begins to grow as a spongy structure inside the endosperm. The radicle quickly forms new roots and establishes the seeding as a new plant Fig.
The base of the cotyledon grows further, turns green and pushes the seed out of the soil. The seed imbibes water and the testa bursts near the caruncle and the radicle grows out.
Leave a Reply Cancel reply. Vivipary is the phenomenon of giving birth to young ones in advanced stage of development.
After this hypocotyl grows due to which two papery cotyledons enclosed by endosperm are pulled out of the soil. Hypogeal germination implies that the cotyledons stay below the ground.