Báo cáo khoa học: Genetic variation of the Croatian beech stands (Fagus sylvatica L): spatial differentiation in connection with the environment

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Báo cáo khoa học: "Genetic variation of the Croatian beech stands (Fagus sylvatica L): spatial differentiation in connection with the environment" Original article Genetic variation of the Croatian beech stands (Fagus sylvatica L): spatial differentiation in connection with the environment M Plazibat B Thiebaut B Comps I Sugar I Trinajstic 1 Université de Bordeaux I, Département de Biologie Végétale, Avenue des Facultés, 33405 Talence Cedex; 2 Centre Louis Emberger, CNRS, BP 5051, 34033 Montpellier Cedex; Institut de Botanique, Université des Sciences et Techniques du Languedoc, Auguste Broussonnet, Montpellier, France; rue 3 Botanicki Zavod, Fakulteta Sveucilista u Zagrebu, Marulicev trg 20/11, 41000 Zagreb; 4 Sumarski Fakultet, Simunska Cesta, 4100 Zagreb, Yugoslavia 15 October 24 (Received 1990) April 1990; acceptedSummary — Thirty-five beech stands located in Croatia, (Yugoslavia) have been analysed using 6polymorphic enzymatic loci. Three of them (PX-1, PX-2, GOT-1) seem to be more or less influencedby selection since their allelic frequencies are related to climatic conditions. The total gene diversityis higher for only 1 out of 6 loci in the continental region. Discriminant analyses on allelic frequenciesshow that the Mediterranean Seslerio-Fagetum which grows in rather dry conditions, is an associa-tion apart; and a significant difference exists between 2 groups of Mediterranean beechwoods locat-ed in the highlands and on the plain, respectively. A general tendency towards a heterozygotic defi-cit occurs with the same significance in both regions. Multilocus F-statistics reveal that the totalgenotypic differentiation and its 2 components (intra- and interpopulations) do not differ between the2 regions.genetic differentiation / beech population / Croatia / geographic variationRésumé — La variation génétique des hêtraies croates (Fagus sylvatica L) : différenciationspatiale en relation avec l’environnement. Trente-cinq hêtraies localisées en Croatie (Yougosla-vie) ont été étudiées à l’aide de 6 marqueurs enzymatiques polymorphes. Trois d’entre eux (PX-1,PX-2, GOT-1) semblent plus ou moins soumis à la sélection, en particulier parce que leurs fré-quences alléliques varient parallèlement aux conditions climatiques. La diversité allélique totale estplus élevée pour1 locus sur 6 seulement, en région continentale. Deux analyses discriminantes surles fréquences alléliques montrent : que le Seslerio-Fagetum méditerranéen qui caractérise des stations relativement sèches repré--sente une association originale; une différence significative entre 2 groupes de hêtraies méditerranéennes en fonction de leur loca--lisation soit en montagne, soit à basse altitude. Une tendance générale se manifeste vers un déficiten hétérozygotes de même importance dans les deux régions. Les F-statistiques montrent que ladifférenciation génotypique totale, aussi bien que ses 2 composantes (intra- et interpopulations) nesont pas différentes d’une région à l’autre.différenciation génétique / hêtraie / Croatie / variation géographique* Correspondence and reprints methods and models have been proposed,INTRODUCTION which can best be applied to actual plant populations (Malécot, 1969; Gregorius, genetic structure of beech stands de-The 1975a, b; Van Dijk, 1987).pends on selection and the mating system, Historical factors could also play an im-in addition to gene flow and genetic drift: portant role in the genetic structure ofthese factors induce inter- and intra- beechwoods. After the last glacial period,population genetic differentiation over current beech stands spread out from aspace and time (Kim, 197 ...