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Growth Studies of the Root of Incense Cedar, Libocedrus decurrens. I. The Origin and Development of Primary Tissues

1962; Wiley; Volume: 49; Issue: 3 Linguagem: Inglês

10.2307/2439544

1537-2197

Hugh E. Wilcox,

Flowering Plant Growth and Cultivation

American Journal of BotanyVolume 49, Issue 3 p. 221-236 Article GROWTH STUDIES OF THE ROOT OF INCENSE CEDAR, LIBOCEDRUS DECURRENS. I. THE ORIGIN AND DEVELOPMENT OF PRIMARY TISSUES Hugh Wilcox, Hugh Wilcox Department of Forest Botany and Pathology, State University College of Forestry, Syracuse, New YorkSearch for more papers by this author Hugh Wilcox, Hugh Wilcox Department of Forest Botany and Pathology, State University College of Forestry, Syracuse, New YorkSearch for more papers by this author First published: 01 March 1962 https://doi.org/10.1002/j.1537-2197.1962.tb14932.xCitations: 44AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Abstract Wilcox, Hugh. (State U. Coll. of Forestry, Syracuse, New York.) Growth studies of the root of incense cedar, Libocedrus decurrens. I. The origin and development of primary tissues. Amer. Jour. Bot. 49(3): 221–236. Illus. 1962.—The anatomical features of active and dormant roots of incense-cedar seedlings are described and discussed in relation to various problems of differentiation and morphogenesis. Autoradiographs confirm the presence of a group of relatively inactive cells at the site of the apical initials. During periods of maximum growth activity, the presence of a quiescent center is accentuated by a peak in number of divisions in adjacent tissues. With diminution in growth activity, the peak occurs closer to the quiescent center and the size of the meristem appears to diminish. During dormancy, the configuration of the initial region seems to indicate the existence of apical initial cells which coincide with a minimal constructional center, as determined by studies of cell lineage. Roots whose apical cells retain their meristematic appearance are able to resume growth after a period of dormancy, whereas roots whose apical cells undergo vacuolation are likely to perish. Graphs are presented to show the functional relationships between growth rate and the varying distances from the apical meristem at which the tissues of the root differentiate and mature. Although early differentiation of precursory phloem could be discerned almost as soon as early vacuolation of metaxylem, its recognition was more dependent upon subjective judgment. The functional relationship between differentiation and growth rate was most pronounced in the maturation of protoxylem elements, the development of Casparian strips in the endodermis, the development of suberin lamellae in the endodermis, and by the development of phi layers in the inner cortex. Citing Literature Volume49, Issue3March 1962Pages 221-236 RelatedInformation