Also found in: Dictionary, Medical, Wikipedia.


The embryonic plant stem above the cotyledons.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



the part of the stem in a plant seedling between the cotyledons and the first true leaves (the first internode). In embryos the epicotyl is a conoid outgrowth consisting of primary formative tissue, or meristem. In plants with aboveground shoot formation the epicotyl and the cotyledons appear above the surface of the soil (for example, in beans and melons). In plants having underground shoot development the cotyledons remain in the soil, and the epicotyl is bent into a loop and then straightened; it carries the bud with the first leaves to the surface, toward the light (for example, in peas, plums, and oaks).

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
However, in the experiment I, there was also a significant effect for the explant type, with emphasis on the epicotyl; and in experiment II, there was interaction between the factors.
Epicotyl consists of a uniseriate and hairy epidermis, and collenchymatous and parenchymatous cortex, without typical endodermis.
Hypocotyl and epicotyl explants (2 cm in length) were transferred to WPM supplemented with 6-benzyladenine (BA) (0, 2.5, 5.0, and 10.0 [micro]M) alone or combined with indole-3-butyric acid (IBA) or [alpha]-naphthaleneacetic acid (NAA) (0.5 [micro]M).
Double coty-node explants were obtained by excising out the epicotyls at the cotyledonary junctions and cutting off the hypocotyls 45 mm beneath the cotyledons.
Shoot regeneration of lentil has been previously reported from meristem tips, shoot tips and shoot meristems (Bajaj and Dhanju, 1979; Williams and McHughen, 1986; Singh and Raghuvanshi, 1989; Polanco and Ruiz, 1997), epicotyl (Williams and McHughen, 1986), embryonic axes (Saxena and King, 1987), first nodes and bractlets of immature seeds (Polanco et al., 1988), cotyledonary seedlings (Mallick and Rashid, 1989), nodal segments (Singh and Raghuvanshi, 1989), stem and cotyledonary nodes (Warkentin and McHughen, 1993; Polanco, 2001; Khawar and Ozcan 2002a, Sarker et al., 2003; Khawar et al., 2004; Sevimay et al., 2005) and decapitated embryo (Sarker et al., 2003).
In hypogeal emergence, the cotyledons remain beneath the soil surface and the epicotyl emerges from the soil.
The growing point of the shoot above the point of cotyledon attachment is called the epicotyl, and the section of stem below the cotyledons is called the hypocotyl.
This exercise is introduced with a description of seedling morphology, including root hairs, cotyledons, hypocotyl, epicotyl and plumule.
Soybean BRU1 encodes a functional xyloglucan endotransglycosylase that is highly expressed in inner epicotyl tissues during brassinosteroid-promoted elongation.
The Ministry of Agriculture and the GCNA are also hard at work developing plants from mature female trees using epicotyl grafting, a technique that produces short bushy plants with strong root systems and the capacity to bear fruit within three to four years.
The epicotyl emerges and the cotyledons remain below the soil surface (for example, corn) (Figure 6-23b).