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 ?
01) by the F test for the lengths of the hypocotyl and epicotyl in the four experiments (Table 1), indicating the existence of genetic variability among the genotypes, which enables success when selecting promising materials.
For callus induction, the basal part of the 6 day old seedling hypocotyls were dissected (0.
When groups I and II were compared, the differences in morphological characteristics among the genotypes were highlighted, determining that the two groups had hypocotyls pigmentation, emergent cotyledon, standard color, wings color, string bean color, and darker seeds color.
2000, "Direct shoot regeneration from node, internode, hypocotyls and embryo explants of Withania somnifera".
9] Kiran G, Kaviraj C P, Jogeswar G, Kavi Kishor P B, & Srinath Rao, Direct and high frequency somatic embryogenesis and plant regeneration from hypocotyls of chickpea (Cicer arietinum, L.
2]-tolerant variants were selected from nitrosoguanidine (NTG)-treated suspension cell cultures of cow pea, Vigna unguiculata, initiated from hypocotyl callus and incubated with 18 [micro]g/ml [HgCl.
Daliri et al [4] reported that barley extracts caused a marked reduction in Datura stramonium (thorn apple) hypocotyls and radicle dry weight.
Uptake and accumulation of lead by roots, hypocotyls and shoots of Indian mustard (Brassica juncea L.
Role of abscisic acid and indoleacetic acid in the stunted growth of water-stressed, etiolated squash hypocotyls.