coleorhiza


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coleorhiza

a structure similar to the COLEOPTILE but located around the radicle of young seedlings.
References in periodicals archive ?
a sheath of tissue which encloses the root tip" and designated as a coleorhiza. Figures 5b and 6 show the radicle breaking through the suspensor cap (coleorhiza) during germination.
Homology of the Coleorhiza of Cycad and Grass Embryos
A coleorhiza is found in the embryos of the grass family (Poaceae) but its origin and homology is disputed (Black et al.
In dicotyledonous plant embryos where there is no coleorhiza, the suspensor is either absent as in the Euphorbiaceae or mostly consists of a single strand of cells attached to the initials of the radicle of the embryo proper (Raven et al.
More research on the origin of the coleorhiza is required, but based on the available information, we are postulating that the coleorhiza of the grass embryo as well as the coleorhiza of the cycad embryo is the remaining distal part of the suspensor and both structures are therefore structurally homologous and should be referred to as a coleorhiza.
Groups of 30 seeds were grown at 3 or 17 [degrees] C until they reached the coleorhiza or radicle stage of development; then they were exposed to freezing treatments (0, -3, -6, or -10 [degrees] C) for 2 h.
Proline content was measured by extracting 0.5 g from embryos (coleorhiza and radicle stages) into 118.0 mmol [kg.sup.-1] sulphosalicylic acid, using the acid ninhydrin reaction method (Bates et al., 1973).
Polar lipid fractions were obtained from 1 g of intact embryos (coleorhiza and radicle stages), treated with boiling isopropanol for 1 min immediately after dissection, and maintained at -20 [degrees] C until extraction.
Oxygen consumption of intact embryos germinated at 3 [degrees] C was measured polarographically at 20 [degrees] C with a Clark-type electrode at the coleorhiza and radicle stages.