Intrapopulation and Interpopulation Genetic Variation ofQuercus in Denmark in Denmark

TY - JOUR

T1 - Intrapopulation and Interpopulation Genetic Variation ofQuercus in Denmark in Denmark

AU - Siegismund, Hans Redlef

AU - Jensen, Jan Svejgaard

PY - 2001

Y1 - 2001

N2 - Native Danish oak stands are fragmented and decreasing because of the extensive use offoreign seed sources. Therefore, the population structure of natural Danish oak stands wasanalysed by means of six polymorphic enzyme loci. A total of 17 stands of Quercus robur L.(including an ‘‘outgroup'' sample from The Netherlands), seven Quercus petraea [Matt.] Liebl.and two putative hybrid stands were included in the study. The average genetic diversity wassimilar for the two species as well as for the putative hybrid stands: 0.25 for Q. robur, 0.27 forQ. petraea and 0.26 for the hybrid stands. The genotypic proportions at two (Pgm and Mnr). and 0.26 for the hybrid stands. The genotypic proportions at two (and ) of the six loci showed many signi. cant deviations from Hardy-Weinberg expectations, alwayswith an excess of homozygotes, whereas the remaining four loci accorded to Hardy-Weinbergproportions, suggesting a low level of inbreeding. The differentiation of the Q. petraea and Q.robur populations was quanti. ed with Wright's F-statistics. The within-species component waspopulations was quanti. ed with Wright's -statistics. The within-species component was low, 0.022, re¿ ecting the wind-pollinated reproductive mode of the two species. The betweenspeciescomponent was 10-fold higher, 0.235, indicating two separate groups. A phylogenetictree estimated from allele frequencies also supported the presence of these two groups. Despitethe two well-separated groups in the tree, it was not possible to assign all individuals to thespecies to which they supposedly belonged. In total, 10% of the Q. robur individuals and 14%of the Q. petraea individuals were assigned to the other species, suggesting a limited amountof introgression between the two species. Key words: gene conser×ation, genetic differentiation,isozyme, population structure, Quercus petraea, Quercus robur., , Quercus petraea, Quercus robur.

AB - Native Danish oak stands are fragmented and decreasing because of the extensive use offoreign seed sources. Therefore, the population structure of natural Danish oak stands wasanalysed by means of six polymorphic enzyme loci. A total of 17 stands of Quercus robur L.(including an ‘‘outgroup'' sample from The Netherlands), seven Quercus petraea [Matt.] Liebl.and two putative hybrid stands were included in the study. The average genetic diversity wassimilar for the two species as well as for the putative hybrid stands: 0.25 for Q. robur, 0.27 forQ. petraea and 0.26 for the hybrid stands. The genotypic proportions at two (Pgm and Mnr). and 0.26 for the hybrid stands. The genotypic proportions at two (and ) of the six loci showed many signi. cant deviations from Hardy-Weinberg expectations, alwayswith an excess of homozygotes, whereas the remaining four loci accorded to Hardy-Weinbergproportions, suggesting a low level of inbreeding. The differentiation of the Q. petraea and Q.robur populations was quanti. ed with Wright's F-statistics. The within-species component waspopulations was quanti. ed with Wright's -statistics. The within-species component was low, 0.022, re¿ ecting the wind-pollinated reproductive mode of the two species. The betweenspeciescomponent was 10-fold higher, 0.235, indicating two separate groups. A phylogenetictree estimated from allele frequencies also supported the presence of these two groups. Despitethe two well-separated groups in the tree, it was not possible to assign all individuals to thespecies to which they supposedly belonged. In total, 10% of the Q. robur individuals and 14%of the Q. petraea individuals were assigned to the other species, suggesting a limited amountof introgression between the two species. Key words: gene conser×ation, genetic differentiation,isozyme, population structure, Quercus petraea, Quercus robur., , Quercus petraea, Quercus robur.

M3 - Journal article

SN - 0282-7581

VL - 16

SP - 103

EP - 116

JO - Scandinavian Journal of Forest Research

JF - Scandinavian Journal of Forest Research

IS - 2

ER -