Pankow, H., von Guttenbebg, H.: Vergleichende Studien über die Entwicklung monokotyler Embryonen und Keimpflanzen. H.: Studies in the developmental anatomy of Phlox drummondii Hook. (ed.): Fyziologické a Genetické Princípy Odolnosti Rastlín voči Meteorogénnym Činitelom. (ed.): The Development and Function of Roots. Luxová M.: Some aspects of the differentiation of primary root tissues. Junk Publ., The Hague-Boston-London 1981. (ed.): Structure and Function of Plant Roots. Kubica, Š.: DNA content in metaxylem of barley roots. G.: Anatomical structure of the roots of barley. Heimsch, C.: Development of vascular tissues in barley roots. Hänsel, H.: Studie über seitliche Ausladung und Anzahl der Keimwurzeln verschiedener Gerstensorten mit besonderer Berücksichtigung ihres Verhaltens nach Vernalisation. Hagemann, R.: Anatomische Untersuchungen an Gerstenwurzeln. Čiamporová, M., Luxová, M.: The effect of polyethylene glyeol-induced water stress on the maize root apex. S., Smith, L.: A study of X-ray induced chromosomal aberrations in barley. Academic Press, New York-London 1972.Ĭaldecott, R. M.: Influence of temperature on germination and elongation of the radicle and shoot of corn ( Zea mays L.) -Crop Sci. A DNA autoradiographic and cytophotometric analysis. The basal region of seminal roots thus differs in its ontogenesis from the increase which is formed “ de novo” by the action of root meristem upon seed germination.Īvanzi, S., Brunori, A., D’Amato, F.: Sequential development of meristems in the embryo of Triticum durum. In the seminal root primordia initiated later the non-dividing areas are relatively shorter. The column of central metaxylem characteristic of the smallest number of cell cycles, has, under the given conditions, a mean length of about 22 mm, whereas the pericycle, as the tissue with most prolonged cell division, has a mean length of about 6 mm. The length of this postembryonically non-dividing basal zone is different in individual cell types. Upon desiccation of caryopsis in maturation, and subsequent quiescent period, their development was temporarily broken, proceeding with the onset of germination. The primary root base is formed of cells pre-existing in the seminal root primordium. With progressing growth the root apex becomes thinner, the meristematic region becomes longer, and the differences in the extent of cell division between individual cell types increase. The character of root meristem indicates a reduced water content at the embryonic development of root primordium. The root meristem is reactivated after the primary root primordium has broken through the sheath-like coleorrhiza and emerges from the caryopsis as the primary root. In the root primordia initiated later, the zone with completed cell division is relatively shorter, in the youngest primordia the non-meristematic cells may be lacking. On germination, the restoration of growth processes begins in this non-meristematic region of root primordium by cell elongation, with the exception of the zone adjacent to the scutellar node, the cells of which do not elongate but continue differentiating. It is formed by root meristem covered with the root cap, and by a histologically determined region with completed cell division. The primary root primordium is developmentally most advanced. In addition to the primary seminal primordium, the so-called secondary seminal root primordia are also initiated in a barley embryo.
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