Hypocotyl

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Related to hypocotyls: radicle, endosperm

hypocotyl

[′hī·pə‚käd·əl]
(botany)
The portion of the embryonic plant axis below the cotyledon.

Hypocotyl

 

in sprouting plants, the section of the stem extending from the root collar (the zone between the main stem and the root) to the place of attachment of the cotyledons. In the embryo, the hopocotyl is the rudimentary stem. The sprouts of some plants have an elongate hypocotyl that bears assimilative cotyledons. This type of aboveground germination characterizes hornbeam. In other plants the hypocotyl is underdeveloped, and the cotyledons do not appear on the surface. Such underground germination is typical of the pea and the oak.

The anatomical structure of the hypocotyl retains its embryonic character. It may give rise to adventitious shoots, roots, or leaves (when the apex of the epicotyl is removed, as in cyclamen). In some plants the hypocotyl becomes the repository of nutrients (for example, the tuber in cyclamen). In many root crops, including the turnip, carrot, and sugar beet, the hypocotyl consists of the fleshy part of the storage organ, which is found between the stem base and the root proper.

L. V. KUDRIASHOV

References in periodicals archive ?
Callus formation and shoot regeneration resulted in all hormone concentrations used for the hypocotyl and cotyledon explants in our study.
Seedlings (Figure 1A and C) are phanerocotylar and epigeal, with axial root, collet visible for presenting slight constriction, hypocotyl long, cylindrical and green, and epicotyl relatively short, cylindrical, green, hairy, with scale like leaves.
Effects of each treatment were evaluated throughout the entire plantlet growth period by monitoring the following characteristics: germination (%), fresh weight (g), hypocotyl length (cm), leaf length (mm), leaf width (mm), and number of leaves per plantlet.
Statistical studies on anatomical modifications in the radicle and hypocotyl of cotton induced by NaCl.
On day 10, the length of hypocotyl, radicle and the biomass of each seedling were measured by selecting five seedlings randomly from each petri dish [42].
170 for hypocotyl length), and length or width of sporangiophore (Table 3) (r=-0.
Soy hypocotyls (soybean variety Kenfeng15, Heilongjiang Province, China, harvested in 2010 in Heilongjiang Province, China) were provided by Heilongjiang Jiusan Oil & Fat Co.
1991), JORDAN and BOTTI (1992) studying the cultivar Concha Lisa reported very good response in the induction and development of adventitious shoots from hypocotyls, unfortunately with a low rate of rooting success.
1] BAP (D3), mature cotyledonary states were obtained that produced leaves, hypocotyls and secondary roots after being transferred to germination conditions.