Allozyme Frequency Distributions in Five European Populations of Black Pine (Pinus nigra Arnold). I. Estimation of Genetic Variation Within and Among Populations. II. Contribution of Isozyme Analysis to the Taxonomic Status of the Species

1994

S. 20-30

zahlr. Lit. Ang.

Unselbständiges Werk

200051510

Silvae Genetica 1994 ; 43,Nr. 1, S. 20-30

European black pine (Pinus nigra Arnold) is generally considered a collective species with many taxonomic problems. Genetic variation in 5 natural populations of Pinus nigra (Austria, Bulgaria, Greece, Corsica, Calabria) was investigated, at the enzyme level, by using the technique of starch gel electrophoresis. Isozyme patterns of 10 enzyme systems (MDH, 6PGD, MR, IDH, PGM, DIA, AAT, LAP, PGI, GDH) were studied. Analysis, using haploid megagametophyte tissue, demostrated that the allozyme variants in the above enzyme systems were coded by a total of 42 structural genes in the 16 readable loci. In one of these loci (IDH), no variants were found. The results of this study showed the followin: a) The loci (isozymes) of DIA appeared in MR enzyme system as well. b) On the averqage, 70,0% of the analyzed loci were polymorphic, while the number of alleles detected per locus (A/L) ranged from 1.87 (Calabria, Greece) to 2.31 (Bulgaria) with a mean value for all studied populations of 2.025 alleles per locus. c) Heterozygosity ranged from 0.180 (Corsica) to 0.257 (Bulgaria). d) 94% of the total variation of the species was due to intrapopulation gene diversity. e) Isozymes contributed differently in the total variation of the species. f) Isozyme variation is a useful tool for the taxonomy of Pinus nigra, since it can discriminate either different subspecies or different populations within a given subspecies. g) The most appropriate enzyme systems for classivication of the subspecies (ssp. laricio, nigra (austriaca) , pallasiana) were MDH, DIA, 6PGD and AAT. h) There was a clear distinction between laricio group (Calabria, Corsica) and austiaca group (Austria, Bulgaria). i) The Greek provenance was closer to the austriaca group.