The importance of magnesium (Mg) is often overlooked in modern crop production. Tomato (Solanum lycopersicum L.) is commonly grafted onto appropriate rootstock to improve the nutrient uptake, which may have a negative effect on the tomato Mg leaf concentration and possibly influence the carbohydrate partitioning required for optimal crop yield and quality. The aim of this study was to screen tomato cultivars and rootstocks under Mg deficiency using two experiments. The first experiment included a panel of 14 tomato cultivars and 10 rootstocks grown with 1 or 0.1 mM Mg in nutrient solution. The second experiment consisted of four cultivars either self-grafted or grafted onto four rootstocks chosen from the first experiment. In both experiments, most of the plants grown under low-Mg conditions, on average, had a higher biomass production. The magnesium concentrations in the leaves and stems (but not in the roots) of both cultivars and rootstocks, non-grafted or grafted, were significantly higher under optimal Mg supply. Regarding the Mg content, the differences between the Mg supplies were up to three-fold for cultivars, up to two-fold for the rootstocks, and up to five-fold for the combinations of grafted plants. Our results showed that genotypic differences between used tomato cultivars and rootstocks in response to Mg can be observed at early developmental stages and can possibly serve as a tool in screening programs, but further research is needed to assess their relationship with long-term cultivation.

The essential oil of Helichrysum italicum (Roth) G.Don, commonly known as immortelle, is produced in Mediterranean countries to meet the increasing demand of the cosmetic and pharmaceutical industries. This study focused on the analysis of secondary metabolites, specifically essential oils, extracted from plants grown from the seeds of natural immortelle populations collected along the eastern Adriatic coast and cultivated ex situ under uniform conditions. Field trials were conducted to determine whether the observed variability was due to phenotypic plasticity or local genetic adaptation. Eighteen natural immortelle populations were sampled, hydrodistilled and their essential oil composition determined by gas chromatography-mass spectrometry. A total of 84 compounds were identified. Eighteen essential oil compounds were present in concentrations greater than 5% in at least one sample of 18 populations. The populations differed significantly in nine essential oil compounds: Limonene, linalool, nerol, neryl acetate, trans-caryophyllene, neryl propionate, ar-curcumene, β-selinene and δ-selinene and the differences were attributed to genetic adaptation to the native environment. Three chemotypes were identified within which the populations were grouped. Results showed a significant and strong correlation between biochemical and bioclimatic distance, with 22.4% of biochemical differentiation between populations explained by bioclimatic distance. Correlations between the 18 main compounds and the bioclimatic variables of the populations’ native environment revealed that BIO14 Precipitation of driest month and BIO15 Precipitation seasonality, were the most informative. These results can serve as a first step for future selection of immortelle populations with desirable adaptations to obtain commercial cultivars that ensure high quality immortelle essential oil.

Extreme environmental conditions affect the synthesis and accumulation of bioactive metabolites in halophytic plants. The aim of this study was to investigate the presence and quantity of key health-promoting phytochemicals in Croatian sea fennel, one of the most popular Mediterranean halophytes with a wide range of uses. The EOs were characterised by a high content of limonene (up to 93%), while the fatty acid profile shows a low content of oleic acid and the presence of valuable linoleic acid (ω-6) and linolenic acid (ω-3) in high percentages. The dominances of lutein and α-tocopherol were also confirmed in all samples. The results confirm the great variability in the chemistry of sea fennel populations in the Mediterranean region, with significant differences in the composition of the Croatian samples compared to the others, as well as the presence and high concentrations of the analysed bioactive compounds that contribute to the plant's health-promoting attributes.

Sea fennel ( Crithmum maritimum L.) is an edible halophytic species rich in various valuable phytochemicals, and has accordingly, been used in traditional medicine and nutrition since ancient times. The aim of this study was to investigate the chemical composition of sea fennel flowers from three regionally (ecologically) different locations on the Croatian Adriatic coast (Pag, Kor & ccaron;ula, Cavtat). The profiles of essential oils (EOs), fatty acids (FAs), tocopherols, and phenolic compounds (total phenolics, flavonoids, and tannins) as well as associated antioxidant capacity were analysed. The flowers collected at the northernmost site had the lowest contents of total phenolic compounds, limonene in the EO and unsaturated FAs, but the highest content of alpha-tocopherol, one of the best-known plant lipophilic antioxidants. On the other hand, the flowers from Kor & ccaron;ula and Cavtat contained high amounts of phenolics, especially chlorogenic acid (7.99 and 13.27 mg/g dry plant matter, respectively), resulting in high antioxidant activity of the samples. Despite these differences in composition, which may be related to the geographical location of the sampling site, sea fennel flowers from all locations can be considered a valuable source of important health-promoting phytochemicals.

Background: Dalmatian Zagora has experienced significant depopulation trends over recent decades. The area is very interesting because of its rich biodiversity of species as well as its history of the use of wild foods. Since there is a danger of permanent loss of knowledge on the use of wild edibles, we focused our research on recording traditions local to this area. Methods: We conducted interviews with 180 residents. Results: A record was made of 136 species of wild food plants and 22 species of edible mushrooms gathered in the area. The most frequently collected species are Rubus ulmifolius Schott, Cornus mas L., Portulaca oleracea L., Asparagus acutifolius L., Sonchus spp., Morus spp., Taraxacum spp., Amaranthus retroflexus L., Cichorium intybus L., and Dioscorea communis (L.) Caddick & Wilkin. Conclusions: The list of taxa used is typical for other (sub-)Mediterranean parts of Croatia; however, more fungi species are used. The most important finding of the paper is probably the recording of Legousia speculum-veneris (L.) Chaix, a wild vegetable used in the area.

A capacity to determine the provenance of high-value food products is of high scientific and economic interest. With the aim to develop a tool for geographical traceability of Croatian extra virgin olive oils (EVOO), multielement composition and 13C/12C isotope ratio in EVOO as well as the geochemistry of the associated soils were analysed in samples collected from three regions along the Croatian Adriatic coast. Soil geochemistry was shown to influence the transfer and elemental composition of EVOO. The most discriminating variables to distinguish EVOO from different regions were S, Mo, Rb, Mg, Pb, Mn, Sn, K, V and δ13C. The predictive models achieved high sensitivity and specificity, especially when carbon isotope composition was added. The results suggest that interregional geographical traceability of Croatian EVOO is possible based on matching their multielement composition with that of the soils in the provenance area.

Institute for Adriatic Crops and Karst Reclamation, Put Duilova 11, 21000, Split, Croatia Institute for the Study of Medicinal Plants „Josif Pančić“, Tadeuša Koščuška 1, Beograd, Serbia University of Zagreb, Faculty of Agriculture, Department of Seed Science and Technology, Svetošimunska cesta 25, 10000 Zagreb, Croatia Centre of Excellence for Biodiversity and Molecular Plant Breeding (CoE CroP-BioDiv), Svetošimunska cesta 25, HR-10000 Zagreb, Croatia

Leaves play a central role in plant fitness, allowing efficient light capture, gas exchange and thermoregulation, ensuring optimal growing conditions for the plant. Phenotypic variability in leaf shape and size has been linked to environmental heterogeneity and habitat characteristics. Therefore, the study of foliar morphology in plant populations can help us to identify the environmental factors that may have influenced the process of species diversification. In this study, we used European wild pear (Pyrus pyraster (L.) Burgsd., Rosaceae) as a model species to investigate the phenotypic variability of leaves under different environmental conditions. Using leaf morphometric data from 19 natural populations from the north-western part of the Balkan Peninsula, a high level of variability among and within populations were found. Leaf traits related to leaf size were more variable compared to leaf shape traits, with both influenced by geographic and environmental factors. Consequently, patterns of isolation by environment (IBE) and distance (IBD) were identified, with IBE showing a stronger influence on leaf variability. Multivariate statistical analysis revealed that European wild pear populations from the north-western part of the Balkan Peninsula can be divided into two morphological clusters, consistent with their geographical distance and environmental conditions. Our results confirm a high level of phenotypic variability in European wild pear populations, providing additional data on this poorly studied species, emphasizing phenotypic plasticity as a major driver in the adaptation of this noble hardwood species to rapid climate change.

A potential of rare earth elements (including yttrium) (REY) accumulation in olives is increasing due to enhanced use of REY in human activities. REY transfer to extra virgin olive oil (EVOO) is little studied, and characterising the relationships between soil properties and REY concentrations in olive leaves, pomace and EVOO can enhance our understanding of soil-plant interactions. Three different soil types (reclaimed karst, rendzina and cambisols), with the sum of REY concentrations (54–364 μg g−1) among the highest in European soils, were characterized for their pH, organic carbon, total carbonates and the applied agronomic practice. Aluminium, calcium, iron, phosphorus and REY were determined in soil (total and plant-available), olive leaves, pomace and EVOO. REY were mainly excluded from plant uptake and only small amounts of REY were transferred to leaves (0.2–652 ng g−1), pomace (0.001–10 ng g−1) and EVOO (<0.5–33 pg g−1). Soil REY availability (0.001–1685 ng g−1) and plant uptake increased with increasing soil acidity. Leaf REY concentrations were mainly explained by plant-available REY and pH. There was an indication of enhanced REY plant availability being associated with low available phosphorus and soil ploughing. Soil properties influence REY uptake and further partitioning to leaves, fruits and EVOO.

The tomato is an important horticultural crop, the cultivation of which is often under influence of abiotic and biotic stressors. Grafting is a technique used to alleviate these problems. Shortage of water has stimulated the introduction of new irrigation methods: deficit irrigation (DI) and partial root-zone drying (PRD). This study was conducted in two spring–summer season experiments to evaluate the effects of three irrigation regimes: full irrigation (FI), PRD and DI on vegetative growth, leaf gas-exchange parameters, yield, water-use efficiency (WUE), nutrients profile and fruit quality of grafted tomatoes. In both years, the commercial rootstocks Emperador and Maxifort were used. In the first year, the scion cultivar Clarabella was grown on one stem and in the second year the cultivar Attiya was grown on two stems. Self-grafted cultivars were grown as a control. In both experiments, higher vegetative traits (leaf area and number, height, shoot biomass) were recorded in tthe plants grafted on commercial rootstocks. The stomatal conductance and transpiration rate were higher under FI. Under DI, transpiration was lowest and photosynthetic WUE was highest. Photosynthetic rate changed between irrigation treatments depending on plant type. In both years, the total yield was highest in grafted plants as result of more and bigger fruits per plant. In the 2nd year, grafted plants under FI had higher yield compared to PRD, but not to DI, while self-grafted plants did not differ between irrigation treatments. WUE was highest in DI and PRD treatments and in grafted plants. Leaf N, P, K and Ca was highest in tthe plants grafted on Emperador and Maxifort, while more Mg was measured in self-grafted plants. More Ca and Mg were recorded in tthe plants under DI and PRD. Fruit mineral concentrations were higher in tthe plants grafted on commercial rootstocks. Total soluble solids differed between irrigation regarding plant types, while fruit total acidity was higher in Emperador and Maxifort. In conclusion, our study showed that grafted plants could be grown under DI with minor yield reduction with 30–40% less water used for irrigation. Moderate DI could be used before PRD for cultivation of grafted tomato and double stemmed plants did not show negative effect on tomato yield so it can be used as standard under reduced irrigation.

For two years, the tomatoes (cv. 'Belle' and 'Clarabella'), ungrafted, self-grafted and grafted onto the 'He-man' rootstock, were grown under two irrigation regimes, i.e., partial-root zone drying (PRD) and fully irrigated (FI), to investigate whether grafting can alleviate drought stress and promote water-use efficiency (WUE). The grafted plants under the FI regime had the highest vegetative growth, which was the result of more leaves and greater leaf area and were only significantly different from the PRD grown ungrafted plants. The grafted plants had the highest yield as a result of the greater number of larger fruits and the yield did not differ between the irrigation treatments. No differences were found in the leaf NPK concentrations, while the Ca and Mg were higher under the PRD regime. The ungrafted plants under the PRD regime had the highest total soluble solids and acidity in the fruit juice. The grafted plants had a significantly higher WUE, more pronounced in the PRD regime. The different types of irrigation did not influence the vegetative growth and the yield in the greenhouse grown grafted tomato. The PRD and rootstock effects should be additionally investigated with deficit irrigation.

An important part of agriculture in the European Mediterranean area is olive (Olea europaea L.) production. Characterising the relationships between properties of different soils where olive is grown and nutrient status in olive leaves can enhance our understanding of soil-plant interactions. Three different soils (Terra rossa, Rendzina, Lithosol) were characterized for their physical and chemical characteristics; plant-available nutrients were extracted with ammonium nitrate. Soils, soil extracts and leaf digests were analysed for nutrients and for nitrogen in soils and leaf. A redundancy analysis (RDA) was applied to elucidate relationships between soil properties and leaf nutrients. As revealed by RDA, leaf concentrations of Mg, K, Ca and micronutrients were explained by available Mg, total carbonates and soil organic carbon in topsoil. Leaf concentration of Na was associated with total Na in topsoil. Copper and Mo deficiencies were detected in plants grown in Lithosol, and Mg, P, Mn and Zn deficiencies were noted in all plants. Through appropriate agronomic techniques, Lithosols can be used for olive groves, but they have significant limitation regarding nutrient availability. Our results support the relevance of using soil nutrient variability to provide a basis for optimisation of measures for olive groves.

Cilj je bio utvrditi komponente vegetativnog i generativnog rasta, prinosa i kvalitete ploda rajcice cijepljene na vlastiti korijen (pozitivna kontrola) kao i na Solanum podloge u uvjetima reduciranog navodnjavanja. Biljke uzgajane s deficitarnim navodnjavanjem i djelomicnim zasusivanjem korijena imale 30% vecu efikasnost koristenja vode. Također, biljke uzgajane na podlogama su ocekivano pokazale vecu efikasnost koristenja vode u odnosu na prinos svježih plodova rajcice. Istraživanja su pokazala da uzgoj na 2 izboja/grane rajcice cijepljene na Solanum podloge uz deficitarno navodnjavanje naglaseno smanjuje troskove bez velikog utjecaja na prihod.

A pedo-geochemical survey was carried out in olive groves of the island Brac. The island of Brac, located in the central part of the Adriatic Sea, is part of the central Dalmatian island group. The complex pedological structure of the island is caused by a great variability of its karst features. The objective of this study is to determine geochemical soil composition (multielemental analysis) of major soil types (anthropogenically modified lithosol, terra rossa-rhodic cambisol and rendzic leptosol) on which the olive trees are cultivated. Topsoil (0-30 cm) and subsoil (30- 60 cm) samples were collected from 7 locations and their basic chemical and physical properties were determined. Multielemental composition (total content of more than 40 major, trace and rare earth elements) were determined by using High Resolution Inductively Coupled Plasma Mass Spectrometry after microwave digestion of soil samples with mixture of mineral acids. Additionally, concentrations of several important soluble plant-available elements were determined in topsoil samples and compared with total soil element content. Obtained results should demonstrate how different soil types of the studied olive growing region differ in pedological and geochemical composition. Such differences should be one of the mayor factors causing differences in olive oil multielemental composition and consequently one of the principal ways for establishing the olive oil geographic traceability