This study attempts to provide a deeper insight into the current genetic status of 12 Bulgarian autochthonous sheep breeds using microsatellite (SSR) markers. A total of 600 individuals from 50 flocks were analyzed using a panel of 13 SSR markers. In total, 228 alleles were found in the studied microsatellite loci. The mean number of alleles, the effective number of alleles, and the polymorphic information content (PIC) values per locus were 17.54, 5.250, and 0.799, respectively. The expected heterozygosity (He) for all breeds ranged from 0.70 to 0.82. The within-population heterozygote deficit (Fis) varied from −0.03 to 0.1, reflecting significant levels for 10 of the 12 breeds. The average genetic differentiation (Fst) was 0.046, revealing a low discrimination between the breeds. The genetic distance, principal coordinate analysis, and the structure analysis showed that two of the studied breeds—Local Stara Zagora/SZ/ and Local Karnobat/MK/—were the most distinct sheep populations. The Bayesian clustering approach suggested poor breed differentiation for the remaining 10 sheep breeds. The results suggest that proper management strategies and specific breeding policies need to be implemented in Bulgaria to avoid the intermixing of breeds and to reduce the erosion of breed purity observed in some breeds.

In spite of the increasing industrial cultivation of lavender (Lavandula angustifolia Mill.), no genetic linkage map and mapping of QTLs (quantitative trait locus) has been reported for Lavandula species. We present the development of a set of SSR (simple sequence repeat) markers and the first genetic linkage map of lavender following the genotyping of a segregating population obtained by the self-pollination of the industrial lavender variety Hemus. The resulting genetic map comprises 25 linkage groups (LGs) corresponding to the chromosome number of the lavender reference genome. The map includes 375 loci covering a total of 2631.57 centimorgan (cM). The average marker distance in the established map is 7.01 cM. The comparison of the map and reference genome sequence shows that LG maps cover an average of 82.6% of the chromosome sequences. The PCR amplification tests suggest that the developed SSR marker set possesses high intra-species (>93%) and inter-species (>78%) transferability. The QTL analysis employing the constructed map and gas chromatography/mass spectrometry (GC/MS) dataset of flower extracted volatiles resulted in the mapping of a total of 43 QTLs for the accumulation of 25 different floral volatiles. The comparison of the genome location of the QTLs and known biosynthetic genes suggests candidate genes for some QTLs.

In spite of the increasing industrial cultivation of lavender (Lavandula angustifolia Mill.) and developed genomic resources, no genetic map has been reported for lavender or other Lavandula species. Here we present the development of a set of SSR markers and the construction of the first genetic linkage map of L. angustifolia following the genotyping with SSR and SRAP markers of a segregating population obtained by self-pollination of the industrial variety Hemus. The resulting genetic map comprises 25 linkage groups /LGs/ corresponding to the chromosome number of the lavender reference genome. The map includes 375 loci covering a total of 2518,9 cM. The average marker distance in the established map is 7,05 cM. The number of markers on each LG ranges from 9 to 26, with an average number of 15. The orders of SSR loci in most of the LGs aligns well with the order of SSR loci in the reference genome. The overall comparison of the LG maps and reference chromosome sequences shows that the LG maps cover between 49,2% and 99,4% of the chromosome sequences, with an average of 84,4% per chromosome. The PCR amplification of genomic DNA from L. angustifolia var. Hidcote Blue, L. latifolia and the intersectional hybrid L. × heterophylla var. Big Boy James suggests that the developed SSR marker set possesses high intra-species (> 93%) and inter-species (> 78%) transferability and could be successfully applied in various genetic diversity studies, the development of integrated maps and an anchor SSR set for the genus Lavandula.

We report the development of a procedure for ultrasound-assisted microscale extraction of metabolites from the flowers of Saint John’s wort (Hypericum perforatum L.), designed for comparative metabolite analysis of plants from genetic resource collections and natural and segregating populations. The procedure involves high-throughput methanol extraction of metabolites from ground-frozen flowers at a selected stage of flower development, which is carried out in a standard 2 mL Eppendorf tube. A total of 18 compounds, including chlorogenic acid, catechins, glycosylated flavonoids, hypericins, and hyperforin, were identified based on LC/DAD/QTOF analysis, of which 16 could be detected in the UV-Vis spectrum. Two alternative versions of the procedure were evaluated: the “single-flower” procedure, including repeated collection and analysis of single flowers from the tested plant, and the “bulk-flower” procedure, employing the collection of a bulk flower sample from the tested plant and analysis of a portion of the ground sample. The results showed excellent technical reproducibility of the “single-flower” procedure when used with the suggested combination of the peak areas for the proto- and stable forms of pseudohypericin and hypericin. Application of the developed “single-flower” procedure for comparison of the plants derived from seed progeny of the apomictic line Hp93 revealed significantly lower metabolite variation among the apomictic progeny plants compared to the variation observed among plants belonging to different genotypes.