Isoenzymatic differentiation in putative hybrid swarm population (Pinus mugo Turra x P. sylvestris L.) from "Torfowisko Zieleniec" peat-bog

Abstract

Isoenzyme variability of eight groups of individuals from different parts of putative hybrid swarm population (P. mugo Turra x P. sylvestris L.) from "Torfowisko Zieleniec" peat-bog complex was studied at ten enzymatic loci. Differences in allelic frequencies distribution among particular samples of the Zieleniec population were statistically significant at 9 loci, as shown by G2- statistics. Chi-square test indicated that in each of studied subpopulations frequencies of alleles at some loci (2-5) differed significantly from frequencies expected for a homogeneous population. Heterozygosity values and also a genotypic polymorphism in studied population confirmed the existence of large genetic variation. Wright's fixation indices (F) showed some excess of homozygotes in majority studied groups of individuals, notably higher in some subpopulations. Gene diversity coefficient for 8 subpopulations was high (GST=9.4%). However, when MDH C locus was excluded from the calculation, its value decreased to 2.8%. Presented data demonstrated notable differentiation of subpopulations within studied pine population, comparable with the differentiation among different populations of coniferous species.

Keywords

• Pinus mugo
• isoenzymes
• subpopulations
• genetic structure
• gene diversity
• hybridization