Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế đề tài: Estimation of Fagus sylvatica L mating system parameters in natural populations. | Ann Sci For 1994 51 163-173 Elsevier INRA 163 Original article Estimation of Fagus sylvatica L mating system parameters in natural populations D Merzeau 1 B Comps 1 B Thiébaut J Letouzey 1 Laboratoire dÉcologie Génétique Departement de Biologie des Végétaux Ligneux Université Bordeaux I avenue des Facultes 33405 Talence Cedex 2 Université Montpellier II Institut de Botanique 163 rue A-Broussonet 34000 Montpellier 3 CNRS Centre Louis-Emberger BP 5051 34033 Montpellier France Received 1st February 1993 accepted 20 September 1993 Summary The mating system of beech Fagus sylvatica L was investigated using polymorphism at 4 allozyme loci and the multilocus model of Ritland and Jain 1981 . Beech appears to be a highly outcrossing species the outcrossing rate ranges from to 1. No significant differences were found in outcrossing rates according to environmental factors or among or within trees. Comparison of singlelocus and multilocus estimates indicated that little or no inbreeding occurred. Outcross pollen pool was not homogeneous and heterogeneity in pollen allelic frequencies was observed even among nearby trees. A possible explanation may be the temporal variability of the pollen pool due to variation in flowering time and to matings between phenologically synchronous trees. mating system outcrossing rate pollen heterogeneity beech Resume Estimation des paramètres du mode de reproduction de Fagus sylvatica L. Le mode de reproduction du hêtre Fagus sylvatica a été étudié à raids de 4 marqueurs alloenzymatiques GOT1 MDH1 SOD1 etIDHI etdumodèle multilocus de Ritland et Jain 1981 dans 4 populations frangaises I une en foret d lssaux dans les Pyrénées-Atlantiques les trois autres dans le massif de I Aigoual La Serreyrèdes Pio du Four et Sommet tableau I . Dans la foret d lssaux 3 parcelles presentant des physionomles differentes ont été étudiées une parcelle à forte densité foret une autre située en lisière de foretet la troisième formee d arbres isolés. Les .