The genus Abies is represented in southern Balkans by A. alba, A. cephalonica, and A. borisii-regis. To infer the status of southern-Balkans firs, as well as the extent and patterns of introgression within this taxonomical complex, we analyzed genetic variation patterns of 29 indigenous fir populations in Bulgaria, Macedonia, Greece, and Calabria using a combination of maternally and biparentally inherited markers. Three mitochondrial lineages were observed, one comprising Calabrian populations and two distributed in the Balkans, coinciding with A. alba and A. cephalonica. The boundary between lineages is sharp; only two populations containing a mixture of haplotypes were found. Bayesian analysis of population structure based on seven nuclear microsatellite (nSSR) loci revealed the existence of two clusters whose proportions exhibited a latitudinal cline with a width of 2.38 (< 255 km). Populations in the center of the latitudinal cline exhibit the most symmetrical, the flattest, and the broadest distributions of cluster proportions within individual tree genomes. A neighbor-net network reflects the cline resulting from the Bayesiananalysis. The observed variation patterns are not consistent with the hypothesis of A. borisii-regis as a monophyletic taxon or a stabilized hybridogenous species resulted from ancient hybridization; the taxon rather is a product of recent introgression.

No abstract

Seed orchards are an important source of seeds with improved genetic quality. Here we present results of a study on the genetic composition of seed orchards crop of Austrian black pine (Pinus nigra Arn.). Two seed orchards were included in the study &ndash; a clonal seed orchard established near Sliven, and a seedling seed orchard, established in the region of Simitli. The outcrossing rates were higher in the clonal seed orchard (Sliven), 0.873 and 0.806 multi-locus (tm) and single-locus (ts) estimates, respectively. The same values were 0.623 and 0.530, respectively, in the seedling seed orchard (Simitli). The inbreeding coefficient was positive in both cases, but was significantly different from zero in the clonal seed orchard only (0.101 vs. 0.032). Thus, the two studied seed orchards demonstrate different genetic efficiency. The results are discussed in relation to seed orchard management and efficiency.&nbsp;