Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp Original article đề tài: Internal levels of plant growth regulators during in vitro culture of wild cherry (Prunus avium L.). | 117s Ann. Sci. For. 1989 46 suppl. 117S-120S Forest Tree Physiology E. Dreyer et al. eds. Elsevier INRA Internal levels of plant growth regulators during in vitro culture of wild cherry Prunus avium L. p. Label1 D. Cornu1 B. Sotta2 and E. Miginiac2 1 INRA Station d Amelioration des Arbres Forestiers Ardon 45160 Olivet and 2 Université Laboratoire de Physiologie du Développement des Plantes 4 pl. Jussieu T53-E5 75252 Paris Cedex 05 France Introduction In vitro micropropagation of wild cherry is presently one of the main commercial ways to clonally propagate this species Cornu and Boulay 1986 . In order to extend this technique to a large number of clones it seems necessary to improve our knowledge of the behavior of the explants during the in vitro culture. Since plant growth regulators PGR play an important role in this technique Margara 1961 our attention was drawn to the effect of exogenous PGR on hormonal levels in the explants. Materials and Methods Wild cherry explants were cultured according to the procedure described by Riffaud and Cornu 1981 . The micropropagation technique can be schematically divided into 3 stages the multiplication stage when axillary bud growth is promoted by an almost equal amount of indole-3-butyric acid IBA rM and benzyladenine BA pM in the culture medium the elongation phase which was not studied and the rooting phase in which IBA pM alone promoted root formation. Hormonal measurements were made during the multiplication and the rooting stages. For each measurement 48 explants were divided into 3 parts the apical part including the apex sensu stricto and the youngest leaves inserted in the short internodes of the stem tip the middle part of the explants bearing the oldest leaves at the axis whose axillary buds started to grow during multiplication treatment and the basal part including the portion of the stem inserted into the culture medium where roots were formed during the rooting stage. For each series
