Greek Cultivars Research Articles

The Detection of viruses in olive cultivars in Greece, using a rapid and effective RNA extraction method, for certification of virus-tested propagation material

Although Greece is the world’s third largest olive production country, information about the presence of olive viruses is limited. A survey for the presence of virus infections in the ten most important Greek cultivars was conducted in a germplasm collection olive grove located in Chania, Crete. Samples were RT-PCR assayed for the presence of Arabis mosaic virus (ArMV), Cherry leafroll virus (CLRV), Strawberry latent ring spot virus (SLRSV), and Olive leaf yellowing-associated virus (OLYaV), amplifying part of the capsid protein (ArMV), the 3΄UTR (CLSRV, SLRSV) or the HSP70h (OLYaV) gene. Total RNAs were purified using the Trizol method, yielding good quality and purity, thereby confirming application of the method as a rapid economic extraction protocol for detection of olive viruses. SLRSV was the most predominant virus, with an infection rate of 55%, followed by CLRV and OLYaV in 5% of the tested samples. ArMV was detected only in one sample. Mixed virus infections were also commonly detected. The DNA amplicons of the obtained viruses from the infected samples were sequenced. The partial sequences of ArMV, CLRV and SLRSV from olives, which are reported for the first time, showed 74-100% nucleotide similarity with available homologous sequences from other crops, whereas OLYaV isolates showed high sequence variability of 25%. The phylogenetic analysis based on olive-OLYaV HSP70h partial-nucleotide sequences grouped the olive isolate sequences according to the geographical origins of the host germplasm collection. This is the first official report of the occurrence of olive viruses in Greece, emphasizing the need to implement a certification programme for production and distribution of high-quality (virus-free) olive propagation material, in Greece and more generally in the Mediterranean basin.

Spatial distribution of nutrients and morpho-physiological indicators of salinity tolerance among five olive cultivars - The use of relative nutrient concentration as an efficient tolerance index

Olive is the most important fruit tree species grown in Mediterranean basin, where many times it grows under saline conditions, due to irrigation with low quality water. Olive response to salinity is cultivar dependent and the evaluation of native genotypes is an important tool in finding tolerant genetic material. For this reason, five Greek olive cultivars, i.e. “Koroneiki”, “Gaidourelia”, “Lefkolia Serron”, “N-K Gigas” and “Throumbolia”, were evaluated regarding their tolerance to sodium chloride salinity (0, 50, 100 and 200 mM). All cultivars exhibited a significant reduction of growth, while the most severe symptoms were found in “Gaidourelia” while “Lefkolia Serron” presented the least symptoms. The latter exhibited the lowest sodium concentration in the leaves and the highest in the roots. Both potassium to sodium and calcium to sodium ratios were high in “Gaidourelia” leaves and stems, suggesting that the use of nutrient concentration for comparison of olive tolerance among cultivars could lead to erroneous results. The best indicator proved to be the determination of nutrient relative concentration compared to corresponding cultivar’s control, as “Gaidourelia” exhibited the highest sodium relative concentration as well as the lowest nutrient ratios, revealing its inability to restrain sodium in the root level.

Screening Olive Leaves from Unexploited Traditional Greek Cultivars for Their Phenolic Antioxidant Dynamic.

Quality characteristics of olive products significantly depend on cultivar (cv), among other factors. In this study, seven traditional, noncommercial Greek cultivars, along with the commercial Spanish Arbequina cv., were examined for the phenolic antioxidant dynamic of their leaves. Polar extracts (aqueous, methanol, and ethanol) were analyzed for Total Phenol (TP), Flavonoid (TFL), Hydroxycinnamic Acid Derivatives (THAD), Flavonol (TFLVN) contents, DPPH radical scavenging ability, and Ferric Reducing Capacity (FRAP). Selective characteristics of olive leaf methanol extracts for all cultivars were re-examined on a second sampling period. Olive leaf is considered a rich source of phenolic antioxidants total phenol content reaching 29.3 ± 1.3, 30.6 ± 0.4, and 27.0 ± 1.1 mg caffeic acid/g dry leaf for aqueous, methanol, and ethanol extracts, respectively) and all cultivars were considered of equal bioactive dynamic. TP data derived from Folin–Ciocalteu and another spectrophotometric assay employed presented a high correlation for all examined cases (R2 = 71.5–86.9%). High correlation (R2 = 0.92) was also found between TP and FRAP findings of aqueous extracts. Olive leaf is considered a promising source of phenolic antioxidants irrelevant to cultivar and therefore even cultivars less effective for oil or table olive production could be efficiently exploited for the bioactive dynamic of their leaves.

Physicochemical Characteristics and Antioxidant Potential of the Greek PDO and PGI Virgin Olive Oils (VOOs)

The present review covers advancements in registered PDO/PGI VOOs in Greece per year and administrative region since 1992, when the first regulation for protection of geographical origin products was issued in the European Union. Evidence for quality, purity, and nutritional characteristics is presented and discussed. Most PDOs are coming from Crete and Peloponnese, the two major olive oil producing areas in Greece. PGI products have also been registered in Greece since 1992, whereas such products are registered in Italy and Spain rather recently. From the point of view of food science, the documents submitted originally for the registration, which are available electronically in the relevant EU portal (DOOR), look outdated and may confuse potential buyers and consumers. Data available for the major Greek cultivar, Koroneiki, cannot always support integrity of products traded in the international market. There are published data for molecular characteristics of almost all cultivars used in the PDO/PGIs that can be used in the certification process. The potential of Koroneiki and other cultivars in antioxidants is not reported in the official documents, though such a piece of information may increase further the added value of these products (e.g., health claim labeling). Similar are the observations from practices in Spain and Italy.Practical Application: PDO/PGI VOOs are popular products among consumers. A positive perspective in the market is expected, granted that the consumer will be properly informed on their intrinsic characteristics and practices that guarantee their authenticity. The review points out that the data for quality, purity, and nutritional characteristics of Greek registered VOOs are limited, and are mainly available for PDOs. It is also pointed out that molecular markers available nowadays and addition of information on natural antioxidants can assist the efforts to protect the integrity of these products in the market and add value because some of them can also bear health claims for their tocopherol and “polyphenol” content.Greece has registered a great number of PDO and PGI virgin olive oils since 1996, most of which are produced in the regions of Crete and Peloponnese, the major olive oil producing regions.

APPLICATION OF AUGMENTED DESIGNS FOR FIELD EVALUATION OF BREAD WHEAT DOUBLED HAPLOID LINES: A PRELIMINARY REPORT

Doubled-haploid is an effective method to produce 100% homozygous lines in asingle generation accelerating the release of new varieties and reducing thecorresponding expenses. However, the existing problem in cases where theadequate quantity of seeds is limited is the inability to evaluate new germplasm inreplicated experiments. In his attempt to confront this problem, Petersen proposedin 1985 the evaluation of new germplasm to be based on its division in blocks andselection to be performed regarding the yield of the randomly repeated control ineach block. The aim of the present study was to use the aforementioned method toevaluate preliminary 37 doubled-haploid lines (DHL). The parental varieties of theDHLs,Greek cultivars “Acheloos” and “Vergina”, were used as controls. For thepurpose of the study, 35 main spikes, one form each DHL and control, were used.The length of the spikes was measured, the number of spikelets was counted, andthe 1000 kernel weight and total yield were recorded. The data analysis revealedthat only one line exceeded the mean number of spikelets of the controls, oneexceeded the mean yield of the controls and two exceeded the mean 1000 kernelweight of the controls (one was even better than the best control). The reportedresults indicate the presence of valuable genetic variability among the DHL aftercrossing cultivars “Acheloos” x “Vergina”. Further research is needed, after DHLsmultiplication, using more plants and locations to draw more reliable conclusions.

Drought Effects on Growth, Water Content and Osmoprotectants in Four Olive Cultivars with Different Drought Tolerance

ABSTRACTThis study investigates the growth and leaf composition of 2-year-old olive trees (Persian cultivars: Fishomi and Dezful and Greek cultivars: Amigdalolia and Conservolia) in response to withholding irrigation for 30 days under a hot and dry environment. Drought stress limited stem elongation, stem diameter expansion, formation of new leaves, leaf area, and specific leaf weight of the plants. However, the effect of drought on inhibition of growth of ‘Fishomi’ plants was higher than the other cultivars. ‘Dezful’, ‘Amigdalolia’ and ‘Conservolia’ were able to preserve higher levels of leaf relative water content and membrane stability index under drought stress. Higher drought tolerance of these plants was related to higher concentration of soluble carbohydrates, proline, potassium, and calcium in their leaves.

Evaluation of bioactive compounds in black table olives fermented with selected microbial starters.

Table olives have been a component of the Mediterranean diet for centuries, with the trend for their consumption currently increasing worldwide. They are rich in bioactive molecules with nutritional, antioxidant, anti-inflammatory or hormone-like properties. In the present study, the concentrations of phenolics, triterpenic acids, carotenoids and vitamins, as well as fatty acid profiles and antioxidant activity, were analyzed in the edible portion of black table olives (Olea europea L.) from Italian (Cellina di Nardò and Leccino) and Greek (Kalamàta and Conservolea) cultivars fermented with selected autochthonous starters and in the corresponding monovarietal olive oils. On a fresh weight basis, Cellina di Nardò and Leccino table olives showed the highest total phenolic content. No significant differences were found with respect to the levels of total triterpenic (maslinic and oleanolic) acids and vitamin E among cultivars. All table olives were characterized by high amounts of oleic, linoleic and palmitic acids. Oils were richer in lipophilic antioxidants (carotenoids and tocochromanols) than table olives, which, instead, showed a higher content of polyphenols and triterpenic acids than oils. The present study demonstrates that fermented table olives are an excellent natural source of unsaturated fatty acids, as well as being nutritionally important health-promoting bioactive compounds. © 2017 Society of Chemical Industry.

Ecophysiological Responses of Two Olive Tree Cultivars (Olea europaea L. CV Koroneiki and Chemlali) Under Three Water Treatments

In this paper, our objective is to assess and compare the effects of three levels of irrigation application on the ecophysiological behavior and plant dry matter accumulation of two young olive tree cultivars Koroneiki, a promising greek cultivar, and Chemlali, the best local cultivar. According to this assessment, we can determine the most efficient water treatment that could be suitable for Mediterranean environments subjected to water shortage conditions. Measurements were made in the green house of the Tunisian Olive tree Institute under normal day-light conditions from March, 16th to April, 21st 2015. Three water treatments were applied which are T100% (control treatment: Daily irrigation at 100% of Available Water Content (AWC)), T50% (Daily irrigation at 50% of AWC) and T0% (Without watering). The results showed that the two olive tree cultivars possess important mechanisms to overtake limited water resources. However, some striking variations existed between the two cultivars studied. Indeed, as water stress increased (T0%), Chemlali maintained longer a high midday leaf water potential compared (- 4.54 MPa) to Koroneiki (- 5.8 MPa). T50% treatment seems to be sufficient for both cultivars. Measurements of total Osmotic Adjustment (OA) showed that olive trees use this mechanism to create very negative leaf water potentials in order to be able to extract water from a dry root environment. The root/shoot ratio of Chemlali plants at T50% treatment was the highest (1.08) comparatively with the other two treatments (0.70 and 0.79 for T100% and T0% AWC water treatments, respectively). This result shows that Chemlali plants valorize low quantities of water (T50%) rather than high quantities (T100%) and Koroneiki plants behave better when it is irrigated at 100% AWC. To conclude, Chemlali plants irrigated at 50% AWC, compared to Koroneiki plants, are the most suitable to tolerate water restriction conditions.

Assessing diversity among traditional Greek and foreign eggplant cultivars using molecular markers and morphometrical descriptors

Eggplant is a widely cultivated vegetable crop of great economic importance. Its long lasting history of domestication, selection and breeding has led to the development of numerous cultivars with variable traits. In the present study, we assessed the diversity levels within and among eleven Greek and foreign cultivars, using 22 morphological descriptors and two different classes of molecular markers (retrotransposon microsatellite amplified polymorphism-REMAP markers and nuclear microsatellites). Our results, in accordance with other studies in the field showed: a) the limited levels of genetic polymorphism within the cultivars; b) the high morphological and genetic divergence existing among them as indicated by the genetic distance values calculated, which could be attributed to selection, inbreeding and bottleneck effects; and c) the lack of concordance among morphological descriptors and molecular markers. Despite these, our analysis showed that the utilization of combinations of markers is an effective method for the characterization of plant material providing also useful diagnostic tools for the identification and authentication of the selected Greek cultivars.

APPLICATION OF RYE SSR MARKERS FOR DETECTION OF GENETIC DIVERSITY IN TRITICALE

Present study aims to testify usefulness of particular rye SSR markers for the detection of genetic diversity degree in the set of 20 triticale cultivars coming from different European countries. For this purpose, a set of six rye SSR markers were used. The set of six polymorphic markers provided 22 alleles with an average frequency of 3.67 alleles per locus. The number of alleles ranged between 2 (SCM43) and 5 (SCM28, SCM86). Resulting from the number and frequency of alleles diversity index (DI), polymorphic information content (PIC) and probability of identity (PI) were calculated. An average value of PIC for 6 SSR markers was 0.505, the highest value was calculated for rye SSR marker SCM86 (0.706). Based on UPGMA algorithm, a dendrogram was constructed. In dendrogram cultivars were divided into two main clusters. The first cluster contained two cultivars, Russian cultivar Greneder and Slovak cultivar Largus, and second included 18 cultivars. Genetically the closest were two Greek cultivars (Niobi and Thisbi) and were close to other Greek cultivar Vrodi. It was possible to separate triticale cultivars of spring and winter form in dendrogram. Results showed the utility of rye microsatellite markers for estimation of genetic diversity of European triticale genotypes leading to genotype identification.

Characterization and Classification of Extra Virgin Olive Oil from Five Less Well‐Known Greek Olive Cultivars

AbstractThe present study comprises the second part of an ongoing study focusing on olive oil from five less well‐known Greek cultivars for three of which there are no data available in the literature regarding their chemical composition. A total of 74 olive oil samples were collected during the harvesting periods 2012–2013 and 2013–2014. Headspace‐solid phase microextraction was applied to determine the olive oil volatile profile. Fifty‐six compounds were identified and semi‐quantified by CG–MS. Furthermore, fatty acid composition, conventional quality parameters and color parameters were determined in an effort to characterize and differentiate olive oils according to cultivar. All samples were characterized as extra virgin olive oils. Data obtained showed significant differences between the cultivars. Multi‐element analysis in combination with chemometrics resulted in a high classification rate of 86.5 % for the combination of volatiles plus color, 89.2 % for the combination of VC plus FA, and 91.9 % for the combination of FA composition plus color plus CQP.

Combination of high resolution melting (HRM) analysis and SSR molecular markers speeds up plum genotyping: case study genotyping the Greek plum GeneBank collection

AbstractIn a germplasm bank collection the conservation and characterization of genetic resources is a prerequisite in order to use the material in breeding projects aiming the creation of new cultivars. In the present study, 54Prunus salicina domesticaandPrunus domesticagenotypes (including seven Greek cultivars), maintained in theex situNational Genebank Collection of Greece, were classified using microsatellite (simple sequence repeat, SSR) markers on high resolution melting (HRM) analysis. The SSR primer pairs were chosen from the published literature as originally designed onPrunusspecies. This combined approach was used to genotype all plum accessions of the collection highlighting the benefits of either method (HRM and SSRs) for cultivar identification. Dendrograms forP. domesticaandP. salicinaand a combined one with all the genotypes assayed were produced. A total of 15 from the 19P. domesticaaccessions analysed, including all the Greek accessions but ‘Avgati Skopelou’, were grouped into the same clade in the combined dendrogram, whereas the remaining four were dispersed into theP. salinicaclades. Bayesian structure analysis confirmed that ‘Avgati Skopelou’ differs from the rest of the Greek plum cultivars since it was not grouped into the same cluster. The combination of HRM and SSRs, provided a considerably faster, cost-effective, closed-tube microsatellite genotyping method for molecular characterization of plum cultivars.

New process for production of fermented black table olives using selected autochthonous microbial resources.

Table olives represent one important fermented product in Europe and, in the world, their demand is constantly increasing. At the present time, no systems are available to control black table olives spontaneous fermentation by the Greek method. During this study, a new protocol for the production of black table olives belonging to two Italian (Cellina di Nardò and Leccino) and two Greek (Kalamàta and Conservolea) cultivars has been developed: for each table olive cultivar, starter-driven fermentations were performed inoculating, firstly, one selected autochthonous yeast starter and, subsequently, one selected autochthonous LAB starter. All starters formulation were able to dominate fermentation process. The olive fermentation was monitored using specific chemical descriptors able to identify a first stage (30 days) mainly characterized by aldehydes; a second period (60 days) mainly characterized by higher alcohols, styrene and terpenes; a third fermentation stage represented by acetate esters, esters and acids. A significant decrease of fermentation time (from 8 to 12 months to a maximum of 3 months) and an significant improvement in organoleptic characteristics of the final product were obtained. This study, for the first time, describes the employment of selected autochthonous microbial resources optimized to mimic the microbial evolution already recorded during spontaneous fermentations.

Differentiation of Greek extra virgin olive oils according to cultivar based on volatile compound analysis and fatty acid composition

Volatile compound (VC) analysis and fatty acids (FA) composition in combination with statistical analysis [Multivariate Analysis of Variance/Linear Discriminant Analysis (MANOVA/LDA)] were used for the differentiation of extra virgin olive oils (EVOO) according to cultivar. A total of 104 olive oil samples from six Greek cultivars were collected during the harvesting period 2012–2013. Fifty‐six VC were identified and semi‐quantified by Head Space‐Solid Phase Microextraction‐Gas Chromatography/Mass Spectrometry (HS‐SPME‐GC/MS). FA composition was determined by Gas Chromatography‐Flame Ionization Detector (GC‐FID). The application of MANOVA/LDA to total VC and FA showed that 34 VC and 9 FA were significant for the differentiation of olive oil cultivar. Based on volatiles’ analysis a classification rate of 83.0% was achieved. The respective classification rate for FA analysis was 92.1% while that of the combination of VC and FA was 93%.Practical applications: This research documents that VC and FA composition could play an important role in the differentiation of cultivar origin of EVOO. Furthermore, researchers had the opportunity to study the characteristics of some less‐known olive oil varieties such as Galano from Chalkidiki and Samothraki from Samothraki island. The results obtained may aid toward the labelling as “Protected Designation of Origin” (PDO) or “Protected Geographical Indication” (PGI) for EVOO from these olive cultivars.Differentiation of Greek olive oil samples according to cultivar based on instrumental analysis and chemometrics.

Growth, Ion Uptake, and Yield Responses of Three Indigenous Small-Sized Greek Tomato (Lycopersicon esculentum L.) Cultivars and Four Hybrids of Cherry Tomato under NaCl Salinity Stress

The effect of three sodium chloride treatments (0, 75, and 150 mM) on the growth, yield, and ion uptake of three small-sized Greek tomato cultivars (Santorini Authentic, Santorini Kaisia, and Chios) and four cherry tomato hybrids (Cherelino, Scintilla, Delicassi, and Zucchero) was studied by using a completely randomized block design with seven replicates. The results indicated that Santorini Authentic under 75 mM sodium chloride (NaCl) had reduced its total biomass production (total plant + fruits fresh weight) by only 22% while the relevant percentage decreases of some hybrids were found to be duplicated. Regarding yield characteristics, Zucchero under 75 mM NaCl, followed by Santorini Kaisia and Chios, showed the lowest reduction of the marketable total fruit fresh weight compared to Cherelino and Delicassi. The greater tolerance of Santorini Authentic might be due to the greater sodium and chlorine retention by the roots in combination with the nonsignificant decrease of the leaf potassium.

Morphological cladistic analysis of eight popular Olive (Olea europaea L.) cultivars grown in Saudi Arabia using Numerical Taxonomic System for personal computer to detect phyletic relationship and their proximate fruit composition

Varietal identification of olives is an intrinsic and empirical exercise owing to the large number of synonyms and homonyms, intensive exchange of genotypes, presence of varietal clones and lack of proper certification in nurseries. A comparative study of morphological characters of eight olive cultivars grown in Saudi Arabia was carried out and analyzed using NTSYSpc (Numerical Taxonomy System for personal computer) system segregated smaller fruits in one clade and the rest in two clades. Koroneiki, a Greek cultivar with a small sized fruit shared arm with Spanish variety Arbosana. Morphologic analysis using NTSYSpc revealed that biometrics of leaves, fruits and seeds are reliable morphologic characters to distinguish between varieties, except for a few morphologically very similar olive cultivars. The proximate analysis showed significant variations in the protein, fiber, crude fat, ash and moisture content of different cultivars. The study also showed that neither the size of fruit nor the fruit pulp thickness is a limiting factor determining crude fat content of olives.

Molecular characterization of Greek pepper (Capsicum annuum L) landraces with neutral (ISSR) and gene-based (SCoT and EST-SSR) molecular markers

Thirty landraces were selected from a Gene Bank collection comprising of pepper (Capsicum annuum L.) landraces from across Greece. The genetic variability among the 30 landraces and one commercial greek cultivar, intended for industrial use, was assessed by Inter-Simple Sequence Repeat (ISSR), Start Codon Targeted (SCoT) and Expressed Sequence Tag (EST) - Simple Sequence Repeat (SSR) molecular markers. All genotypes were clearly distinguished in the dendrograms produced, with the ISSR and SCoT dendrograms being the most consistent. Three landraces were grouped together in all dendrogams revealing a possible phylogenetic relationship. Furthermore, EST-SSR markers were combined with High Resolution Melting (HRM) analysis by which the more adequate and confident separation of the landraces was accomplished due to the unique HRM profiles produced. Genotyping the rich Greek pepper germplasm by molecular markers will aid the breeding process towards well adopted Greek pepper cultivars of higher quality and productivity.

Antiradical–antimicrobial activity and phenolic profile of pomegranate (Punica granatum L.) juices from different cultivars: a comparative study

Pomegranate juices from the fruits of the two relatively new Greek cultivars “Persephone” and “Porphiroyeneti” were studied compared to the “Wonderful” cultivar.

Analytical phenolic composition and sensory assessment of selected rare Greek cultivars after extended bottle ageing.

The Hellenic vineyard embraces a large number of native cultivars, which are mostly unexploited for their ageing potential. Therefore, it was thought that analyzing some quality parameters of 14 red wines produced by rare native varieties would be of great importance in obtaining a general picture of their potential for commercial use. Various analytical methods were applied to the selected wines, at bottling and after 8 years of ageing, in an attempt to provide reliable answers to this issue. In addition, it was of interest to investigate the alteration of the phenolic content and color parameters of the wines after extended bottle storage and to evaluate the overall changes with respect to their sensory properties. Most of the oligomeric phenolic compounds identified in the wines studied diminished after 8 years of bottle storage, while significant correlations were obtained between wine chemical composition and sensory data. After 8 years of bottle storage some of the unexploited varieties (Vitis vinifera) were found to be worthy of further study and use for the production of quality wines. Wines with the best sensory characteristics were those made by Limniona, Mavrotragano, Bakouri, Thrapsa and Mavrothiriko, in accordance (more or less) with the results of chemical analyses.

Response of four olive ( Olea europaea L.) cultivars to six B concentrations: Growth performance, nutrient status and gas exchange parameters

A greenhouse experiment was conducted to study the effects of boron (B) on growth, nutrient status, B distribution and gas exchange parameters of olive plants ( Olea europaea L.). One-year-old own-rooted olive plants of the Greek cultivars Megaritiki, Chondrolia Chalkidikis, Amfissis and Kalamon were grown in a sand–perlite medium and irrigated with nutrient solutions containing: 0.27, 0.5, 1, 2.5, 5 and 10 mg L −1 B (0.27 and 10 mg L −1 were considered as control and excess B treatment, respectively). After culturing for 185 days, leaves and stems (from basal and apical part of the shoots) and roots were separately sampled. Our results showed that the final number of leaves per plant was negatively correlated with B concentration in the nutrient solution. Furthermore, in B10.0 treatment, ‘Megaritiki’ had decreased length and number of lateral stems, ‘Chondrolia Chalkidikis’ and ‘Amfissis’ showed decreased length of lateral stems and ‘Kalamon’ decreased length of lateral stems and plant height. In general, dry weight of stems and leaves was not significantly correlated with B concentration in the nutrient solution. B concentration in leaves and stems was linearly correlated with B supply. A linear correlation existed between B concentration of the nutrient solution and that of leaves and stems. At the end of the experiment, B levels in the leaves and stems of B0.27 and B0.5 treatments did not differ significantly. In general, the increase of B concentration in the nutrient solution, negatively affected the nitrogen (N) concentration of leaves and stems while phosphorus (P) and iron (Fe) concentrations were not affected. Furthermore, potassium (K) and calcium (Ca) concentration in stems of plants supplied with 10 mg L −1 B was decreased. In addition, high B supply resulted in increased magnesium (Mg) and manganese (Mn) concentrations in ‘Chondrolia Chalkidikis’ and ‘Amfissis’ and in the decrease of zinc (Zn) concentrations, in all plants. A significant decline in photosynthetic rate at the end of the experiment was observed in the B5.0 treatment regardless of cultivar.