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Recent changes in environmental conditions in populations of peat-bog pine (Pinus uliginosa Neumann) caused rapid decline or even extinction of the species in several stands in Central Europe. Conservation strategies for P. uliginosa require information about the evolutionary history and genetic structure of its populations. Using isozymes we assessed the genetic structure of P. uliginosa from four isolated stands in Poland and compared the results to genetic structures of other closely related pine species including eight populations of Pinus mugo, ten of Pinus sylvestris and one of Pinus uncinata. The level of genetic variability of P. uliginosa measured by the mean number of alleles per locus and average heterozygosity was similar to others related to P. uliginosa taxa from the reference group but it differs among populations. High genetic similarity was found between two populations of P. uliginosa from Low Silesian Pinewood. The populations were genetically distinct as compared to other populations including locus classicus of the species from the peat bog at Batorów Reserve. Very low genetic distance (DN = 0.002) and small genetic differentiation (GST = 0.003) were found between P. uliginosa and P. mugo in the sympatrie populations of the species from Zieleniec peat bog suggesting the ongoing natural hybridisation and genetic contamination of peat-bog pine from this area. Some evidence for skew in allele frequency distribution potentially due to recent bottleneck was found in population from Low Silesian Pinewood. The analysed open pollinated progeny derived from two P. uliginosa stands from Low Silesian Pine- wood showed the excess of homozygotes as compared to the maternal trees indicating high level of inbreeding (F =0.105,F = 0.081). The results are discussed in the context of evolution of P. uliginosa populations, taxonomie relationships between the analysed species and conservation strategies for active protection of peat-bog pine.
Genetic differences between two populations of P. uliginosa from Batorów and Węgliniec were assessed on the basis of 15 allozyme loci. The level of genetic differentiation between them was also compared with genetic differences among the three closely related pine taxa: P. uliginosa, P. sylvestris and P. mugo. A high level of genetic variation was found in both populations of P. uliginosa. The average (Na) and effective (Ne) numbers of alleles per locus amounted respectively to 2.47 and 1.50 in Węgliniec and to 2.67 and 1.52 in Batorów and the percentage of polymorphic loci was 80% and 87%, respectively. Close relationship between the three studied species were confirmed. The genetic differences between the two populations of P. uliginosa were substantial, as the Nei's genetic distance between the two populations (D = 0.040) was larger than between populations of P. sylvestris and between populations of P. mugo. The relatively high level of genetic differentiation between P. uliginosa populations may result from their isolation, small size and possibly different origin of these populations.
Peat-bog pine Pinus uliginosa Neumann has become extinct or rare in many parts of Europe. We have investigated the levels of genetic variation and inbreeding in seeds collected from a highly endangered reserve of this species in Poland, using allozymes as genetic markers. Generally, a high level of genetic variation was observed. The mean expected heterozygosity was 0.376, while average (Na) and effective (Ne) numbers of alleles per locus were 2.45 and 1.67, respectively. Nevertheless, we have detected relatively low levels of outcrossing, and potential biparental inbreeding. The population-wide multilocus outcrossing rate was estimated to be 0.706 (±0.091), while the minimum variance mean of single-locus estimates was distinctly lower (ts=0.611). The estimates of outcrossing calculated for individual trees ranged widely from 0.051 to 1.017, indicating the complexity of outcrossing patterns. The investigated population of P. uliginasa from Węgliniec is small and surrounded by extensive forest stands of P. sylvestris. Our three-year records of phenological observations demonstrated that flowering periods for P. uliginosa and P. sylvestris overlap, allowing for cross-pollination. The possibility of P. uliginosa pollination by P. sylvestris creates a potential danger of genetic erosion of the P. uliginosa gene pool. Nonetheless, based on a species specific cpDNA marker we have found that among 533 seedlings of P. uliginosa there were only six seedlings carrying cpDNA marker specific for P. sylvestris, indicating that such hybridization seems to be rare.
The results of morphological and anatomical studies on Pinus uliginosa needles from newly-discovered localities of this species in Węglowiec (Bory Dolnośląskie) are presented. The data obtained were compared to similar published material on P. uliginosa needles from its loco classico in Batorow and from the lowland locality in Węgliniec Nature Reserve, and to P. sylvestris growing nearby. In terms of needle structure, all three P. uliginosa populations were slightly different. The samples analyzed differed markedly from the sample of P. sylvestris, which contradicts the hypothesis that Scots pine has had a significant influence on the gene pool of P. uliginosa.
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