Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế đề tài:"Assimilate allocation and carbon in Juglans regia L. seedlings. | 832s Ann. Sci. For. 1989 46 suppl. 832s-836s Forest Tree Physiology E. Dreyer et al. eds. Elsevier INRA Assimilate allocation and carbon reserves in Juglans regia L. seedlings A. Lacointe Station de Bioclimatologie INRA Domaine-de-Crouelle F-63039 Clermont-Ferrand France Introduction This study was undertaken to answer 3 questions some of which have been debated by several authors . Hansen 1967 and Kandiah 1979 on apple trees or Petrov and Manolov 1973 on peach trees. Can a growing organ simultaneously be active as a storage organ Is a given storage area active at different times Are the dynamics of reserves different between the stem part which will bear the next year s shoot and the rest of the stem plants were selected for homogeneity and fed for 5 h with 14CO2 using a large assimilation chamber 24 plants at a time received a total of MBq 500 pCi . Another set of 72 plants were fed on October 8th primary growth had stopped in late August 2-3 plants were sampled the day after feeding and 3 d later then 8-9 monthly until bud-break late May They were divided into 5 perennial organs Fig 1 plus leaves when present frozen in liquid nitrogen freeze-dried and weighed. The 14c distribution was analyzed qualitatively by autoradiography and quantitatively with an argon-methane flow counter after dry-grinding. Results Materials and Methods Plant material Walnuts Juglans regia L were sown outdoors on 5 June 1986 in individual pots provided with an automatic irrigation system. Germination occurred around June 20th. The stem elongation was initially quite fast until early July building up the lower stem with scaly leaves then much slower building up the upper stem with true leaves. 4C feeding On August 1st late primary growth only a few short internodes were still being built Fig. 1 72 Autoradiographs schematic drawings Fig. 2 The taproot In both experiments the labeling pattern was stable after 3 days and remained unchanged until bud-break. In the August experiment .
