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Several oregano genotypes belonging to Origanum vulgare subsp. hirtum (Link) Ietsw., O. onites L., and O. majorana L., Lamiaceae, from Greece, were genetically and chemically studied. Genetic analysis with microsatellite markers, showed the differentiation of O. onites genotypes from O. vulgare subsp. hirtum and O. majorana ones and revealed several diagnostic alleles which can be used for authentication of the plant raw material. The metabolic profiles of all oregano volatile oils contained carvacrol or thymol as their main volatile component, and others in lower concentration, such as γ-terpinene and p-cymene. Multivariate analyses revealed a clear distinction of the genotypes, based on their chemical composition. According to the Mantel test, there was no correlation between the metabolic and the genetic profile of the oregano genotypes. Molecular identification and chemical characterization contribute to the valorization of oregano material from Greece, which is in great demand, due to its high-quality properties and the various uses in food and pharmaceutical industry.

There are many factors determining the strawberry organoleptic profile and they are difficult to define. In this study, the sensory, physical, and chemical quality characteristics, the antioxidant properties as examined using ferric reducing antioxidant power (FRAP) and 1-diphenyl-2-picrylhydrazyl (DPPH) assays, the lactone concentration, and the FaFAD1 expression of ripe strawberries (cv. Camarosa, Florida Fortuna, and Sabrina) from Greece were evaluated and their interrelationships were investigated.; Results: 'Camarosa' had the highest antioxidant capacity and polyphenol content, although significant intra-cultivar variations of sugars, solid soluble content/titratable acidity (SSC/TA), red color intensity, sweetness, and hardness were recorded. In 'Sabrina' there was a constant lactone presence and FaFAD1 expression; it also had the lowest ascorbic acid content, the highest pH, SSC/TA index, firmness, and sweetness. 'Fortuna' showed the lowest sweetness and aroma indices, whereas 'Camarosa' had intermediate ones. Overall, firmness was correlated with hardness, while pH and SSC/TA index correlated with juiciness and sweetness. Both γ-decalactone and γ-dodecalactone concentrations were correlated with FaFAD1 expression and pH, but they did not solely determine the aroma sensory perception. In total, FRAP values were positively correlated with ascorbic acid and polyphenol content, and negatively with pH.; Conclusions: Significant inter- and intra-cultivar variation was recorded, revealing the impact of the genotype and underlining the effect of microenvironmental and cultivation conditions on quality and sensory perception. © 2018 Society of Chemical Industry.; © 2018 Society of Chemical Industry.

Greek sage (Salvia fruticosa Mill.) is an aromatic-medicinal plant, indigenous to Greece, rich in bioactive ingredients, henceforth in demand by the food, pharmaceutical and agricultural industries. Its use is hampered by the fact that Greek sage cultivars are not available at the moment which is a prerequisite for a sustainable crop production. Development of cultivars requires knowledge of the material’s phenotypic range of expression, of the existing genetic diversity, and of the effects of the environment on the phenotypic expression. For this purpose, essential oil (EO) and morphological traits were measured in a hundred individual plant samples of ten populations, from different locations of the Peloponnese (Greece). Significant differences among populations, both in yield and composition of EO, as well as in the morphological traits were observed. In fact, the EO components could assign most of the samples to their respective population (80–100%). The EO yield and main components were consistent, in one of the populations within a three year period of sampling, showing predominance of genetic background. Morphological traits showed a wide range of variation related to altitude, latitude and microclimatic conditions of the collection site, but were not correlated to the EO profile. For the genetic analysis and assessment of the diversity of the populations nine microsatellite markers were used. STRUCTURE analysis revealed the formation of four genetic groups, while PCoA managed to separate all populations according to their location of origin. Correlation was found between the EO composition and genetic diversity by the Mantel test. The present results demonstrate the high variability of the morphological and EO traits, and the high genetic diversity of the Greek sage populations growing in the Peloponnese. This diversity serves as the background for the selection of genotypes towards the development of S. fruticosa cultivars with high EO yield, superior EO composition and desirable agronomic traits.

Hypericum perforatum has plenty of uses in traditional medicine and is the source of top-selling herbal drugs and food supplements. The secondary metabolite chemistry for most of the nearly 500 Hypericum taxa is still unknown, even though they are used interchangeably. In the present study, we characterized four Hypericum populations from Achaia, Greece, belonging to H. perforatum ssp. veronense, H. perfoliatum, H. triquetrifolium, and an uninvestigated taxon, H. empetrifolium ssp. empetrifolium, in terms of their essential oils and polar bioactives in methanolic extracts via GC-MS, LC-HRMS, LC-DAD-MS, and HPLC-DAD. We also performed sequence analysis of nrITS to explore the genetic profile of these taxa and to examine whether their genotype is correlated to the metabolome. Sixty-three non-volatile compounds, phloroglucinols in their majority, and over one hundred (113) volatiles, mostly sesqui- and mono- terpenes, were detected. The concentration of the major polar constituents varied greatly among samples. In particular, phloroglucinols' diversity and abundance in H. empetrifolium ssp. empetrifolium was remarkable. The PCA and Biplot analysis revealed the contribution of each compound to the total chemodiversity and also revealed certain compounds that contribute to the discrimination of the samples. Sequence analysis of nrITS revealed different genetic profiles and markers which can be used for the identification of the four Hypericum taxa. The Mantel test showed a relatively strong correlation between the genetic profile and the volatile compounds and low with the main polar metabolites.

The aim of this study was to contribute to the characterization of Crocus taxa using morphological, phytochemical and genetic analysis. The styles of C. cartwrightianus, C. oreocreticus and C. laevigatus, collected in the island of Crete were compared to those of C. sativus cultivated at the region of Western Macedonia (Greece). Phytochemical analysis was done using GC–MS and HPLC methods, while ISSR markers were used for their genetic characterization. Safranal was the major volatile component of the styles of C. sativus, 4-hydroxy-2,6,6-trimethyl-1-cyclohexene-1-carboxaldehyde of C. cartwrightianus and C. oreocreticus, and isophorone of C. laevigatus. C. sativus had the highest content of crocins and picrocrocin, while C. laevigatus the lowest (only 5% of C. sativus' quantity) and negligible amount of picrocrocin. According to both the genetic and the chemical analysis, C. cartwrightianus is more related to C. oreocreticus, while C. sativus and C. laevigatus are more distinct. Concordance between the two different types of data was also confirmed by the Mantel test (r = 0.932, P = .68). This is the first thorough screening of secondary metabolites (volatile and non-volatile) and also genetic and morphological characters of wild Crocus styles simultaneously, that contributes to the identification and valorisation of genotypes with similar to C. sativus traits which may be introduced as new cultivars through breeding.

There are many factors determining the strawberry organoleptic profile and they are difficult to define. In this study, the sensory, physical, and chemical quality characteristics, the antioxidant properties as examined using ferric reducing antioxidant power (FRAP) and 1-diphenyl-2-picrylhydrazyl (DPPH) assays, the lactone concentration, and the FaFAD1 expression of ripe strawberries (cv. Camarosa, Florida Fortuna, and Sabrina) from Greece were evaluated and their interrelationships were investigated.'Camarosa' had the highest antioxidant capacity and polyphenol content, although significant intra-cultivar variations of sugars, solid soluble content/titratable acidity (SSC/TA), red color intensity, sweetness, and hardness were recorded. In 'Sabrina' there was a constant lactone presence and FaFAD1 expression; it also had the lowest ascorbic acid content, the highest pH, SSC/TA index, firmness, and sweetness. 'Fortuna' showed the lowest sweetness and aroma indices, whereas 'Camarosa' had intermediate ones. Overall, firmness was correlated with hardness, while pH and SSC/TA index correlated with juiciness and sweetness. Both γ-decalactone and γ-dodecalactone concentrations were correlated with FaFAD1 expression and pH, but they did not solely determine the aroma sensory perception. In total, FRAP values were positively correlated with ascorbic acid and polyphenol content, and negatively with pH.Significant inter- and intra-cultivar variation was recorded, revealing the impact of the genotype and underlining the effect of microenvironmental and cultivation conditions on quality and sensory perception. © 2018 Society of Chemical Industry.

Grafting of elite cultivars onto tolerant rootstocks is an advanced strategy to increase tomato tolerance to sub-optimal temperature. However, a detailed understanding of adaptive mechanisms to sub-optimal temperature in rootstocks and scions of grafting combinations on a physiological and molecular level is lacking. Here, the commercial cultivar Kommeet was grafted either onto ‘Moneymaker’ (sensitive) or onto the line accession LA 1777 of Solanum habrochaites (tolerant). Grafted plants were grown in NFT-system at either optimal (25°C) or sub-optimal (15°C) temperatures in the root environment with optimal air temperature (25°C) for 22 days. Grafting onto the differently tolerant rootstocks caused differences in shoot fresh and dry weight, total leaf area and dry matter content of roots, in stomatal conductance and intercellular CO2 and guaiacol peroxidase activity but not in net photosynthesis, sugar, starch and amino acid content, lipid peroxidation and antioxidant enzyme activity. In leaves, comparative transcriptome analysis only identified differentially expressed genes responding to sub-optimal root temperature when ‘Kommeet’ was grafted onto the sensitive but not onto the tolerant rootstock. 1509 and 2046 differentially expressed genes responding to sub-optimal temperature were identified in LA 1777 and ‘Moneymaker’ rootstocks, respectively. In tolerant rootstocks down-regulated genes were enriched in main stress-responsive functional categories and up-regulated genes in cellulose synthesis suggesting that cellulose synthesis may be one of the main adaptation mechanisms to long-term sub-optimal temperature. Down-regulated genes of the sensitive rootstock showed a similar response, but functional categories of up-regulated genes pointed to induced stress responses. Down-regulated genes of the sensitive rootstock showed a similar response, but functional categories of up-regulated genes pointed to induced stress responses. Rootstocks of the sensitive cultivar Moneymaker showed in addition an enrichment of up-regulated genes in the functional categories fatty acid desaturation, phenylpropanoids, biotic stress, cytochrome P450 and protein degradation, indicating that the sensitive cultivar showed more transcriptional adaption to low temperature than the tolerant cultivar that did not show these changes. Mainly defense-related genes were highly differentially expressed between the tolerant and sensitive rootstock genotypes under sub-optimal temperature. These results provide new insights into the molecular mechanisms of long-term sub-optimal temperature tolerance of tomato.

The genus Minuartia is highly diverse in the Mediterranean region and includes several endemic and locally restricted species. The genetic variation of three Minuartia species (M. dirphya, M. parnonia, M. wettsteinii) which are endemic to Greece was investigated, aiming to also develop effective conservation plans for their protection. Minuartia dirphya and M. wettsteinii are known to occur only at their type localities, each forming a small population, while M. parnonia is more widespread with seven populations located in the south-east Peloponnese. Genetic diversity was estimated using ten chloroplast microsatellite and five REMAP markers. The chloroplast microsatellite markers exhibited limited polymorphism among species only, while REMAP revealed a significant amount of genetic variation at the population and species level. All the analyses performed (dendrograms, PCoA, STRUCTURE) showed clear differentiation among species, highlighting M. wettsteinii as the most genetically distant. As shown by AMOVA, a degree of differentiation was detected within M. parnonia, where 41 % of the total variation was partitioned among populations and 59 % to the individuals within them. At the species level, the highest genetic diversity (PPB = 75.86 %, Hj = 0.2728, I = 0.3509) was observed in M. parnonia, followed by M. dirphya (PPB = 55.17 %, Hj = 0.2350, I = 0.2767), while the lowest was observed in M. wettsteinii (PPB = 28.74 %, Hj = 0.1449, I = 0.1498). Scarce gene flow (N m = 0.5451) was observed among M. parnonia populations. The current study is important for developing conservation management plans for the three threatened Minuartia species.