Genetic characters and diameter growth of provenances of scots pine (Pinus sylvestris L.)

Correlation between genetic characters and growth parameters was studied with respect to four provenance samples, which are part of a 47-year-old provenance trial of Scots pine. Two samples with superior growth were contrasted with two weakly growing samples. Based on a sample size of 100 trees per provenance, genotypes were monitored at 16 enzyme coding gene loci. Effects between genetic and growth traits were studied by means of two-factorial analysis of variance and linear regression models with respect to diameter classes and subsets of elite and non-elite trees within provenance samples as well as diameter subsets of pooled provenance samples. Significant deviations are evident among the genetic structures of the four provenance samples. In each sample, deviations from Hardy-Weinberg structures are indicated at single loci. Inbreeding does not primarily account for such deviations. The study of diameter classes reveals that an increase of stem volume tends to coincide with an increase of the observed heterozygosities in three out of four provenance samples. In the case of two-locus genotypes at 6-PGDH and MDH-C, significant effects of heterozygosity on diameter growth are observed. By focusing the two most frequent alleles at six differentiation effective gene loci, significant relations to diameter growth can be particularly verified for two locus combinations including AAT-A. The genetic comparison of the elite and non-elite trees, the first subset reveals larger values for diversities, differentiation and heterozygosities than the second does. The genetic comparison between the subset of the 50 thinnest and the 50 thickest trees among the 400 individuals indicates higher values for the genetic multiplicity and the gene pool and multilocus diversity for the subsets with superior growth. It is concluded for the present that isoenzyme gene markers reveal an indicative potential for quantitative traits.