Industrial Pollutants Tend to Increase Genetic Diversity: Evidence from Field-Grown European Scots Pine Populations

The effect of heavy metal and gaseous pollution on genetic make up due to selection and mortality was studied in eight European Scots pine (Pinus sylvestris L.) populations. Genetic structure of these populations was evaluated after 13 years of growth at two sites, one located in the vicinity of a copper smelter in Glogow (southern Poland) and another in a control area (Kornik, central Poland). Based on data from 10 enzymatic loci, studied by starch gel electrophoresis, the following genetic parameters were characterized: mean number of alleles and genotypes per locus, heterozygosity and genotype polymorphism index, genetic diversity among sites and genetic similarity according to Nei and Roychoudhury. Most of the parameters differed both between sites as well as between pairs of populations. Mean multilocus observed heterozygosity and genotype polymorphism indices were 8% and 6% lower respectively at the control site than in the polluted one. Populations from the site polluted by heavy metals demonstrate higher genetic diversity then those from the control. Genetic similarities showed differentiation of particular populations from both locations in response to industrial pollution. These results provide evidence that the general pattern of adaptation strategy of populations to pollution stress is connected with increasing genetic variation. The best isoenzymatic markers for monitoring changes in the genetic structure of Scots pine populations under the influence of industrial pollution are fluorescent esterase (FEST), glutamic-oxaloacetatic transaminase (GOT-A and GOT-B), alcohol dehydrogenase (ADH), malate dehydrogenase (MDH-A) and shikimate dehydrogenase (ShDH-A) loci.