Search

AbstractThe present study aimed to evaluate the genetic diversity and differentiation of Pinus nigra Arnold, the European black pine, populations located in protected forested areas in three countries from the Balkan and Mediterranean region: Bulgaria, Greece, and Cyprus. Totally, 175 DNA samples from P. nigra plants collected from eight populations in these countries were analyzed using three SRAP primer pairs. The applied SRAP markers demonstrated high-resolution power, resulting in the identification of an average of 215 ± 67 polymorphic loci per SRAP primer pair. The analysis of molecular variance (AMOVA) showed that 82% of the observed variation was due to intra-population variation, while 18% was due to inter-population variation. The overall analysis of the population structure suggested low (Fst ≤ 0.01) intra-country differentiation for the populations from Bulgaria and Cyprus and moderate (0.15 ≤ Fst ≤ 0.17) inter-country differentiation. On the contrary, high differentiation between the populations (0.06 ≤ Fst ≤ 0.20) and complex genetic structure were characteristic of the three populations from Greece, relatively closely located in the area of the Pindos National Park. Analysis of the population structure also revealed that one of the Pindos populations belonged to the cluster of Bulgarian populations (Fst ≤ 0.01), showing moderate (Fst ≤ 0.11) to high (Fst ≤ 0.20) genetic differentiation from the other analyzed Pindos populations. The further use of SRAP markers for mapping the genetic diversity among P. nigra populations and identification of local populations diverted from the overall phylogeography-driven pattern in the studied region are discussed.

AbstractThe content of linalyl acetate and the ratio of linalool to linalyl acetate (L/LA ratio) are one of the important parameters that determine the quality of lavender oil. The characterization of a segregating population derived from a self-pollinated Lavandula angustifolia var. Hemus resulted in the identification of a single quantitative trait locus controlling the L/LA ratio (L/LA-QTL) and located on chromosome 8 of the lavender reference genome. The L/LA data analysis demonstrated that plants homozygous for one of the L/LA-QTL alleles had significantly higher linalool content, lower linalyl acetate content and higher L/LA ratio, than the plants which were either heterozygous or homozygous for the other allele. No significant difference was observed for the sum of linalool and linalyl acetate content among these three groups of plants, suggesting that the identified L/LA-QTL is related to an enzyme conversion of linalool to linalyl acetate. The BLAST search revealed that the L/LA-QTL region included a sequence of the LiAAT4 gene of monoterpene acetyltransferase, considered as a candidate gene for the L/LA-QTL locus. Sequence analysis of the LiAAT4 gene of var. Hemus revealed the presence of two alleles differing in two nucleotides and predicted amino acid substitutions. The comparison of the allele configurations of SSR, SRAP and LiAAT4 loci and the L/LA ratio of plants showing recombination in the L/LA-QTL region provided further support that LiAAT4 is a candidate gene underlying the identified L/LA-QTL and controlling the L/LA ratio. The application of molecular markers for the identified L/LA-QTL is discussed.

The genetic and flower volatile diversity of 59 plants from two natural populations of Hyssopus officinalis L. situated 73 km away from each other in typical growing regions for this species in Bulgaria were analysed. Analysis with 10 sequence related amplified polymorphism (SRAP) primer combinations scored a total of 1045 peaks of which 88.7% were polymorphic. Principal Coordinate Analysis (PCoA) and unweighted pair group method with arithmetic mean (UPGMA) clustering revealed clear grouping of samples based on their population origin. However, analysis of the genetic differentiation revealed that the two populations (Godech and Izvor) are genetically similar as shown by the low Fst and Gst values as well as by the low Nei’s genetic distance and high gene flow (Nm). Gas chromatography–mass spectrometry (GC-MS) analysis of flower extracts from the same individual plants that were used in the genetic diversity analysis identified 32 compounds. Principal Component Analysis (PCA) based on compound abundances revealed two major clusters of samples which did not correspond to their population origin. In depth analysis of the compound abundances showed large variation between the two identified clusters including complete presence/absence of major compounds and the existence of two distinct chemotypes corresponding to the identified clusters. Our results indicate that future efforts towards development of genetic resource collections as well as transition towards field cultivation of this species in Bulgaria should take into account the presence of the two identified chemotypes in natural populations and the factors (both genetic and epigenetic) which determine their existence.

We studied the petal number trait in a population obtained after self-pollination of R. x damascena f. trigintipetala following analysis of molecular markers which have previously been mapped near the major dominant locus Blfo/d6 determining this trait in other rose species including R. multiflora and R. hybrida. The results showed that the same genetic mechanism, which determines the petal number trait in R. multiflora and R. hybrida also controls the trait in R. x damascena f. trigintipetala and is related to the dominant effect of a single copy allele in the tetraploid genome of this species. We also analyzed the expression of several flower homeotic genes including R. x damascena APETALA1/FUL-like (paleo AP1 type), R. x damascena euAPETALA 3 (euAP3 line) and R. x damascena AGAMOUS in early stage flower buds corresponding to plants with double and simple flowers. The obtained results showed that only R. x damascena AGAMOUS was differentially expressed between the samples of double and simple flowers, its relative expression being upregulated 3.5-fold in simple flowers. We further cloned and sequenced the four genomic clones of R. x damascena AGAMOUS and studied the potential additive effect of this gene by analysing the segregation of its four alleles in the population of self-pollinated R. x damascena. Analysis of variance of the data for petal number and allele segregation did not show a statistically significant effect of any allele configuration of the AGAMOUS gene on the petal number trait in R. x damascena f. trigintipetala.

A total of 139 endophytic fungal isolates derived from 20 medicinal and aromatic plants were tested for their capacity to ferment rose oil distillation wastewater (RODW). Internal transcribed spacer sequence-based phylogenetic analysis affiliated the collected isolates to seven genera and nine different species, of which Alternaria alternata was the most widely represented. The fungal fermentation of RODW was evaluated through analysis of the sugar and phenolics content and phenolics composition. After cultivation in a small volume of RODW, the performed cluster analysis grouped the isolates in four distinct clusters according to their capacity to ferment RODW sugars and phenolics. Further larger volume shake-flask cultivation of a selected subset of fungi with a pronounced RODW fermentation capacity, outlined three groups of isolates with a distinct pattern and dynamics of sugars and phenolics fermentation. High-performance liquid chromatography analysis of RODW phenolics extracts following the fermentation by the selected fungal isolates showed two main types of changes in phenolics composition: (1) changes in the relative abundance of part of the RODW phenolic compounds, mainly due to utilization of sugar residues from the RODW phenolic glycosides and (2) biosynthesis of new phenolic compounds, most of which are specific to the endophytic fungal isolates used for RODW fermentation. The overall results of the study clearly demonstrate that endophytic fungal isolates represent a rich and untapped source for efficient fermentation of RODW and other agro-industrial phenolics-rich wastewaters and highlight their capacity for directional changes and modification of RODW phenolics composition towards further wastewater phenolics valorization.