THE PHYLLOTAXIS OF THE DATE PALM (PHOENIX ... - Pubhort.org

Concerning the date palm, the chronological curve represents , aperfect and constant response to explain the date palm phyllotaxis. There isno raison to distinguish this curve with the ontological spiral. The twoexceptions described in this paper constitute at the contrary elements thatgive force to this hypothesis. One of these two exceptions, the change ofdirection of the chronological spiral, fits strangely well with the theory ofthe first available space to explain phyllotaxis (Snow, 1962).The link that has been established between leaves chronological curveand two traits of leaves morphology of course reinforces also thehypothesis of the morphogenetic signification of the chronological curve.The practical interests of the results and methods present in this paperare numerous: easy calculation of the total number of leaves or of theleaves production (Ferry, 1988), sampling of leaves of the same rank,rankihg of the inflorescences and of the bunches, accurate phenology withreference to the position, leaves and palm architecture modelisation.LITERATURE CITEDBouguedoura N. Contribution a la connaissance du palmier dattier,Phoenix dactylifer L.; Etude des productions axillaires. These de Doctorat,Univ. d' Alger, 90p.Cottignies A., 1993. Courrier sur les spirales vegetales. La Recherche.24/251: 736.Davis T.A., 1963. The dependance of yield on asymmetry in coconutpalms. J. Genetics, 58:186-215.Davis T.A., 1970. Fibonacci numbers for palm foliar spirals. Acta.Bot. Neer. 19(2): 249-256.Douady S., Couder Y., 1993.La physique des spirales vegetales. Larecherche, 24/250: 26-35.Ferry M., Toutain G., Desfonds V., Louvet J.M., 1988. Morphologicaldifferences' in the developement of date palm vitroplants of variousvarieties. Proc. Symp. on date palm tissue culture, Bagdad, pp 1-16.Hilgeman R.H. , 1951. The differentiation, growth and anatomy of theaxis, leaf, axillary bud, inflorescences and offshoot in Phoenix dactylifera.Ph. D. Thesis, Univ. California, Los Angeles, 140p.570-- - ---