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The sheath surrounding the radicle in monocotyledons.
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 It might be outdated or ideologically biased.



a calyptrate sheath that surrounds the primary root, enclosed in the seed of a plant. It performs a protective function. The coleorhiza is characteristic of cereal grains; it is also present in eucalypti. The growing rootlets rupture the seed (caryopsis), causing it to sprout.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
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Does a cycad seedling have a coleorhiza? Encephalartos 83:28-29.
And the morphological nature of cycad coleorhiza. Plant Science Bulletin 2:9-14.
At the coleorhiza stage, the average [LT.sub.50] was -2.4 [degrees] C for both cultivars, whether treated at 17 or 3 [degrees] C.
Proline, soluble sugars, and fructans accumulated in embryos at the coleorhiza and the radicle stage when seeds were exposed to 3 [degrees] C (Table 2).
Low temperature treatment did not modify the relative distribution of fatty acids of Ot220 or America at the coleorhiza or radicle stages.
Ot220 and America at the coleorhiza and radicle stage following treatment at 17 and 3 [degrees] C (mean [+ or -] SD).
The Cyt c pathway contributed approximately 70% of the total oxygen consumption for both cultivars except at the coleorhiza stage for Ot220 where the contribution was 50%.
Differential cold sensitivity at early stages of development (coleorhiza and radicle), however, could rely more on germination dynamics (e.g., Di, [D.sub.50], and final percentage of germination, Scott and Jones, 1982; Martin et al., 1988) than on [LT.sub.50].
These temperatures are lower than those reported here, of -2.4 [degrees] C and -1.9 [degrees] C for the coleorhiza and radicle stages, respectively.