Geographic population-genetic divergence of the Norway spruce bark beetle Ips typographus in the Czech Republic
1997
Pavlicek, T. | Zurovcova, M. | Stary, P. (Academy of Sciences of the Czech Republic, Ceske Budejovice (Czech Republic). Inst. of Entomology)
Genetic diversity, within and between-population variability was analysed in eight populations of the Norway spruce bark beetle, Ips typographus, collected in the Czech Republic. Geographic distances between populations were from 13 to 173 kilometers. From each population (with one exception) thirty individuals were examined and tested for 17 putative allozyme loci. The following average gene density indices were found: gene diversity He=0.184 (range from 0.164 to 0.209), heterozygosity H=0.07 (range from 0.046 to 0.090) number of alleles per locus A=1.85 (range from 1.6 to 2.0) and allele polymorphism, P=0.38. Wright's among-population variability index was Fst=0.075. Wright's inbreeding coefficient (Fis=0.608) suggested heterozygote deficiency. Significant deficiency of heterozygotes was proved in eight out of ten studied polymorphic loci and in 42 out of 62 combinations of locality and enzyme. Strong deviations from Hardy-Weinberg equilibrium of homozygotes and heterozygotes was demonstrated by outcrossing rate which was found to be as high as 23 percent. Our results for Ips typographus showed high gene diversity within populations, extensive deficiency of heterozygotes, low outcrossing rate, and long-distance gene flow which results in a low amount of among-population differences on a mesogeographic level
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