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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.

In pepper crops, rootstocks that tolerate salt stress are not used because available commercial rootstocks offer limited profits. In this context, we obtained the hybrid NIBER®, a new salinity-tolerant rootstock that has been tested under real salinity field conditions for 3 years with 32%–80% higher yields than ungrafted pepper plants. This study aimed to set up the initial mechanisms involved in the salinity tolerance of grafted pepper plants using NIBER® as a rootstock to study root-shoot behavior, a basic requirement to develop efficient rootstocks. Gas exchange, Na+/K+, antioxidant capacity, nitrate reductase activity, ABA, proline, H2O2, phenols, MDA concentration and biomass were measured in ungrafted plants of cultivar Adige (A), self-grafted (A/A), grafted onto NIBER® (A/N) and reciprocal grafted plants (N/A), all exposed to 0 mM and 70 mM NaCl over a 10-day period. Salinity significantly and quickly decreased photosynthesis, stomatal conductance and nitrate reductase activity, but to lower extent in A/N plants compared to A, A/A and N/A. A/N plants showed decreases in the Na+/K+ ratio, ABA content and lipid peroxidation activity. This oxidative damage alleviation in A/N was probably due to an enhanced H2O2 level that activates antioxidant capacity to cope salinity stress, and acts as a signal molecule rather than a damaging one by contributing a major increase in phenols and, to a lesser extent, in proline concentration. These traits led to a minor impact on biomass in A/N plants under salinity conditions. Only the plants with the NIBER® rootstock controlled the scion by modulating responses to salinity.

Aims 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. Methods 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. Results 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 (

Olive (Olea europaea L.) orchard productivity largely depends on the choice of planted cultivars and their reproductive traits. Simultaneous flowering periods enable cross-pollination and high fruit set in different cultivars. Olive tree is producing both perfect (hermaphrodite) and staminate (male) flowers. Excessive production of male flowers can result in decreased yields resulting from their inability to set fruit. Low ability of pollen to germinate can also impair the productivity. In this study, the reproductive traits were analysed in twelve olive cultivars (‘Carolea’, ‘Cucco’, ‘Frantoio’, ‘Istarska bjelica’, ‘Itrana’, ‘Lastovka’, ‘Leccino’, ‘Levantinka’, ‘Maurino’, ‘Oblica’, ‘Pendolino’ and ‘Rosciola’). The earlier start of flowering was recorded for all cultivars in 2014, while the start date was delayed for nine days in 2015. Simultaneous flowering and full bloom periods were recorded for most cultivars ; however significant discrepancy also appeared for both traits. The highest proportions of staminate flowers were found for ‘Oblica’ and ‘Cucco’ and the lowest for ‘Frantoio’ in both years. Significant differences were found also in the extent of pollen germination between the various cultivars. Pollen germination varied from 3.7% (‘Lastovka’ in 2015) to 30.5% (‘Cucco’ in 2014), and the higher percentages were recorded for ‘Carolea’, ‘Cucco’, ‘Istarska bjelica’, ‘Itrana’, and ‘Oblica’. Our results suggest that the level of pistil abortion, and the success of pollen germination, are genetically determined and are most likely an evolutionary adaptation to redistribute available resources. Differences in environmental conditions over two flowering seasons affected the flowering timing.

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&ndash, 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&ndash, 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.

Olive (Olea europaea L.) is a wind-pollinated, preferentially allogamous species. However, inconsistent results are often reported for the classification of some cultivars as either self-compatible or self-incompatible, probably because of the influence of management and environmental conditions during bloom. Cross- pollination significantly enhances fertilization and fruit set in most olive cultivars. However, this improvement partly depends on the compatibility relationships between recipient and pollinizer trees in the species, where a few cases of cross- incompatibility have been reported recently. Different methods have been used to evaluate the success and inter-compatibility in pollination assays. The most common method for the determination of inter-compatibility is based on the observation of pollen-pistil interactions in cross-pollination trials. This method requires the usage of pollination bags to prevent the access of unwanted pollen grains to the stigmas of recipient flowers and the subsequent observation of pollen-pistil interaction features (pollen adhesion, pollen germination, pollen tube growth in the pistil and fertilization) and/or initial and final fruit set in response to experimental crosses. Lately, simple sequence repeats (SSRs) or microsatellites are increasingly becoming the markers of choice for paternity analysis of seeds to measure the success of crosses, especially when potential pollen donors are multiple and not applied by hand. SSRs offer a reliable way to test the paternity of seeds by checking the presence of parental alleles in the progenies. Knowledge of self-compatibility and cross-compatibility relationships of olive cultivars is a vital factor in the success of olive crosses and, therefore, of breeding programs. The advantages and drawbacks of the different methods to evaluate compatibility relationships within and between olive cultivars are presented in this work.

We report the genome sequence of a Pseudomonas sp. strain isolated from olive knot galls. The genome size is 6.101 Mbp with a G+C content of 58%. A total of 6,137 coding DNA sequences (CDS) were predicted, including 52 tRNA and 4 rRNA genes.

[EN] In vegetables, tolerance to drought can be improved by grafting commercial varieties onto drought tolerant rootstocks. Grafting has emerged as a tool that copes with drought stress. In previous results, the A25 pepper rootstock accession showed good tolerance to drought in fruit production terms compared with non-grafted plants and other rootstocks. The aim of this work was to study if short-term exposure to drought in grafted plants using A25 as a rootstock would show tolerance to drought now. To fulfill this objective, some physiological processes involved in roots (rootstock) and leaves (scion) of grafted pepper plants were analyzed. Pepper plants not grafted (A), self-grafted (A/A), and grafted onto a tolerant pepper rootstock A25 (A/A25) were grown under severe water stress induced by PEG addition (-0.55 MPa) or under control conditions for 7 days in hydroponic pure solution. According to our results, water stress severity was alleviated by using the A25 rootstock in grafted plants (A/A25), which indicated that mechanisms stimulated by roots are essential to withstand stress. A/A25 had a bigger root biomass compared with plants A and A/A that resulted in better water absorption, water retention capacity and a sustained CO2 assimilation rate. Consequently, plants A/A25 had a better carbon balance, supported by greater nitrate reductase activity located mainly in leaves. In the non-grafted and self-grafted plants, the photosynthesis rate lowered due to stomatal closure, which limited transpiration. Consequently, part of NO3- uptake was reduced in roots. This condition limited water uptake and CO2 fixation in plants A and A/A under drought stress, and accelerated oxidative damage by producing reactive oxygen species (ROS) and H2O2, which were highest in their leaves, indicating great sensitivity to drought stress and induced membrane lipid peroxidation. However, drought deleterious effects were slightly marked in plants A compared to A/A. To conclude, the A25 rootstock protects the scion against oxidative stress, which is provoked by drought, and shows better C and N balances that enabled the biomass to be maintained under water stress for short-term exposure, with higher yields in the field., This work has funded by INIA (Spain) through Project RTA2017-00030-C02-00 and the European Regional Development Fund (ERDF). LL-S is a beneficiary of a doctoral fellowship (FPI-INIA).

We report the genome sequence of a Pseudomonas sp. strain isolated from olive knot galls. The genome size is 6.101 Mbp with a G+C content of 58%. A total of 6,137 coding DNA sequences (CDS) were predicted, including 52 tRNA and 4 rRNA genes.

Here, we present the total genome sequence of Pantoea sp. strain paga, a plant-associated bacterium isolated from knots present on olive trees grown on the Adriatic Coast. The genome size of Pantoea sp. paga is 5.08 Mb, with a G+C content of 54%. The genome contains 4,776 predicted coding DNA sequences (CDSs), including 70 tRNA genes and 1 ribosomal operon. Obtained genome sequence data will provide insight on the physiology, ecology, and evolution of Pantoea spp.

Bemisia tabaci is one of the most damaging pests in tomato greenhouse production. The resistance of B. tabaci to insecticides requires a new approach with respect to the integrated management of this pest. The effect of grafting (nongrafted and tomato grafted on the rootstock Arnold) and nitrogen (N) rates (75, 140 and 205 mg/L) on the density of B. tabaci large nymphs (fourth instar to pupae) was studied in 2012. In 2013, large nymphs density was examined in relation to grafting treatments (nongrafted, self-grafted and tomatoes grafted onto the rootstocks Arnold and He-Man) and NO3− : NH4+ ratios (92 : 8, 85 : 15 and 70 : 30). A reduction of B. tabaci population density was found for rootstock Arnold grown at 140 and 205 mg/L N in the nutrient solution. Pupal size decreased with decreasing N fertilization. In the second experiment, rootstocks contributed to a reduction of B. tabaci density at different NO3− : NH4+ ratios. The lowest B. tabaci population density was found on plants grafted onto He-Man rootstock supplied with an 85 : 15 and 70 : 30 NO3− : NH4+ ratio in nutrient solutions. The increased proportion of NH4+ in the 85 : 15 NO3− : NH4+ ratio generally reduced the B. tabaci pupal size for all rootstocks. Grafting and N adjustment could represent useful tools for integrated greenhouse pest management.

Olive trees develop large numbers of flowers, but only a small proportion mature into fruits. The petals, anthers and style, which comprise the larger portion of the flower, drop after anthesis, and rapid fruit growth takes place. During flowering, the reproductive process becomes the plant's dominant sink for carbohydrates, at the expense of vegetative growth, which may affect leaf photosynthesis. The aim of this study was to observe the gas- exchange parameters on mature leaves from 1- year-old shoots in the inflorescence zone and young, fully expanded leaves in cultivars 'Leccino', 'Levantinka' and 'Oblica'. Three measurements were performed, before flower opening, at full bloom and during rapid fruit growth. The photosynthetic rate (A), stomatal conductance (gsw), transpiration (E), and leaf vapor pressure deficit (VpdL) were significantly influenced by cultivar, leaf age and time of measurement. 'Levantinka' and 'Oblica' had higher gsw and E compared with 'Leccino' ; however, A was highest in 'Levantinka' (16.2 μmol m‑2 s‑1), followed by 'Oblica' (14.39 μmol m‑2 s‑1) and 'Leccino' (11.1 μmol m‑2 s‑1). The highest Hydro N tester (HNT) value was measured in 'Oblica' (100.4), followed by 'Levantinka' (68.6), while the lowest was found in 'Leccino' (54.4). Higher A, gsw and E were found for leaves in the inflorescence zone compared with young leaves. At the stage of rapid fruit growth, gsw, Ci and E were higher compared with measurements before flower opening or at full bloom ; however, A and VpdL were higher only when the stage of rapid fruit growth was compared with full-bloom stage. In the period of rapid fruit growth, lower HNT values were observed compared with values found during full bloom. In our study, higher demands for assimilates during fruit development corresponded to the highest values found for gas-exchange parameters.

Plants perceive environmental stress and use this information to modulate their regular pattern of development. Abscisic acid (ABA) mediates plant responses to many abiotic stresses. This study investigated the efficiency of short- versus long-term ABA exposure on critical morphological and physiological responses linked to functional changes in stomata, stomatal density, plant water status, photosynthetic activity and overall growth in bell pepper ( Capsicum annuum L.). ABA was applied to pepper seedlings as foliar at 0, 0.1 or 1.0 mM for 5, 10 or 15 consecutive days. A depressive effect of ABA on net photosynthetic rate (A CO2 ) and stomatal conductance (g s ) compared to control was found after 5-day ABA-exposure at 1.0 mM, and after 15-day ABA-exposure at 0.1 mM and 1.0 mM ABA. Plants quickly resumed the photosynthetic activity since no effect of ABA was found after a longer recovery. Temporary higher leaf water potential was observed in seedlings treated with ABA compared to control. At 17 days after the beginning of the experiment, the number of stomata at adaxial and abaxial side was reduced at 1.0 mM ABA-rate compared to 0.1 mM ABA for each ABA-day of exposure. ABA-rate at 1.0 mM decreased leaf weight, number and area with a more pronounced effect as ABA-days of exposure increased. Stem dry weight was almost unaffected by ABA-rate at 0.1 mM, but 1.0 mM decreased stem weight by 30% after 15-day ABA-exposure. The increased specific root length at 1.0 mM ABA-rate after 5- or 15-day ABA exposure suggested that ABA induced the growth of thinner roots. The delayed effect of ABA-rate and ABA-days of exposure was measured for plants allowed to recover for 23 days after the last application for the longest treatment. Growth parameters were generally affected by ABA after longer recovery. The effect of ABA on modulation of pepper seedlings growth and physiology was dependent on rate and length of exposure but recovery duration was important as well. These results provide new evidences that application of ABA at a specific rate and length of exposure could eliminate the risk of stressing young seedlings to the point of physiological injury as previously reported for some hardening techniques.

Olive oil represents an important ingredient in the Mediterranean diet and is appreciated for both nutritional and sensory properties, often related to geographical area where the olives are grown and the olive cultivar. As consumers demand correct labeling of olive oil, there is a need for analytical techniques that are able to provide data and confirm traceability of origin and authenticity of the oil. Stable isotope ratios have long been known to have enormous potential for food source screening and have been used in authenticity studies for many food products. Results of stable isotope ratios analyzed by EA-IRMS technique are not influenced by cultivar or the agricultural techniques in the groves, and is a valuable tool for geographical discrimination of unknown samples. The carbon isotope ratio (13C/12C) of olive oils was determined by EA-IRMS (Elemental Analyzer – Isotope Ratio Mass Spectrometry). All analyses were performed in triplicates. Analysis of variance was performed on the obtained dana using SAS Institute v9.4 software.

The olive tree response to sequential pollinations is a more accurate procedure in the assessment of effective pollination period and flower life span than procedure based on the calculation of the components of the pollen-pistil interaction. Effective pollination period (EPP) was defined by Williams (1965) as the period during which pollination can result in fruit set. EPP was proposed to be the time the ovules remain fertile minus the time needed for a pollen tube to reach the ovule, providing that this value does not exceed the length of stigma receptivity. The duration of the EPP in fruit trees can be estimated by the microscopic analyses of these three components, but also by the plant response to sequential pollinations in term of fruit set. Here, we compare the estimation of EPP duration under cross-pollination in the main olive cultivars (Olea europaea L.) grown for oil production in Croatia (‘Lastovka’, ‘Leccino’, and ‘Levantinka’) based on these two procedures to discuss the advantages and disadvantages of each estimation and propose the best methodology to assess EPP duration and the capacity of flowers of different age to set fruit. Our comparison highlights that the different procedures provide a contrasting duration of EPP in all olive cultivars here analyzed. EPP based on initial fruit set and final fruit set was between 2 and 3 days, while that based on the microscopic study of EPP components was between 5 and 12 days, depending on the cultivar. We defend that EPP based on fruit set is more accurate and more relevant for growers, and believe that the longer duration of EPP when the estimation is based on the study of the components could be due to wrong assessments of the duration of particular components. In this sense, pollen germination may be a better parameter than pollen adhesion to estimate stigma receptivity. Ovule longevity assessment based on the fluorescence emitted could be an overestimation of the actual ovule readiness for fertilization. Style suitability, not considered in Williams’ equation, plays an important role supporting pollen tube growth toward the ovules and might be also relevant in determining EPP duration.

The aim of this study was to determine the effect of rootstocks on the growth and yield of cucumber (Cucumis sativus L.) plants in soils infested with root-knot nematodes (Meloidogyne spp.) Cucumber ’Adrian’ was grown with its own roots or was grafted onto three rootstocks of Lagenariasiceraria (Molina) Standi. (’Emphasis’, ’S-1’, and ’Gourd’), two interspecific hybrid rootstocks of Cucurbita maxima Duchesne x C. moschata Duchesne (’Strong Tosa’ and ’RS 841 Improved’) and zucchini Cucurbita pepo L. (’Romanesco Zucchini’). The experiments were conducted in commercial greenhouse, with cucumber grafted onto three rootstocks in the first season and onto six rootstocks in the second spring-summer season. The number of leaves was considerably affected by the rootstock in both seasons, and was the highest for the plants grafted onto interspecific rootstocks (28.0 in the first and 44.9 in the second season). The plants grafted onto ’Strong Tosa’ had higher total number of fruits (19.9) and yield (5.38 kg) compared to other rootstocks or non-grafted plants in first season, and the same result was found for two interspecific rootstocks in the second season (6.96 kg and more than 28.9 fruits per plant). The total soluble solids, pH and electrical conductivity of the fruit were not affected by rootstock, while titratable acidity changed with the rootstock type. The grafting of cucumber plants onto different rootstocks was confirmed as an acceptable non-chemical method to compete with the limitations of soils infected with root-knot nematodes, but the effect was highly dependent on the choice of the rootstock.

Most olive cultivars are partially self-incompatible. However, the mechanisms of self-incompatibility are still unclear and the choice of pollinizers for the main olive cultivars becomes difficult especially after the constant introduction of foreign cultivars in new environmental conditions. In order to determine compatibility relationships and to select suitable pollinizers for the main Croatian cultivars, pollen germination, pollen tube growth and fertilization percentage have been assessed in ‘Lastovka’ and ‘Oblica’, as well in the Italian cultivar ‘Leccino’ following self- and cross-pollination treatments in 2009 and 2010 seasons. Massive pollen tube growth, higher pollen tube growth rates, earlier and greater amount of fertilization were found for cross-pollination compared to self-pollination. The flowering periods of the studied cultivars overlapped in a high degree in both years. In ‘Lastovka’, cross-pollination was more efficient than self-pollination regarding pollen germination, tube growth and fertilization. Index of self-incompatibility (ISI), calculated as the ratio of fertilization following self-pollination to that following cross-pollination, was 0.4 and 0.5 in 2009 and 2010, respectively, which categorize this cultivar as partially self-incompatible. Higher ISI was found for ‘Leccino’ (0.7 in 2009; 1.0 in 2010) and ‘Oblica’ (0.5 in 2009; 0.7 in 2010). However, most cross-pollination treatments provided higher fertilization levels than self-pollination, proving that cross-pollination was also beneficial for ‘Leccino’ and ‘Oblica’. Inter-incompatibility reactions between cultivars were not observed.

The reproductive phase has proven to be one of the most temperature sensitive stages in plants. Relatively high or low temperatures, especially during the progamic phase, are often correlated with low fertilization percentages and low fruit setting in different years and orchards. Here, the olive variety ‘Oblica’ was employed in a two year field experiment to assess the effect of temperature on the duration of the flowering period as well as on pollen germination, pollen tube growth, and fertilization percentage. An increase in temperature in the field was caused by covering trees with polyethylene cages. Cultivars ‘Leccino’ and ‘Levantinka’ were used as pollen donor genotypes in the cross-pollination treatment, and pollen from ‘Oblica’ trees was applied in the self-pollination treatment. Pollen germination in vitro was enhanced when pollen grains were exposed to higher temperatures two days before the start of flowering (29% for covered trees vs. 17% for uncovered trees in 2009 ; and 12.3% vs. 10% in 2010). Higher temperatures advanced the appearance of full bloom and shortened the duration of flowering period by one day for ‘Oblica’ trees inside the cages. No significant difference in pollen germination on the stigma was observed between the trees exposed to different temperatures. Pollen donor genotype affected pollen germination in vivo. Temperature had significant influence on pollen tube growth in the style and on fertilization percentage, but the reaction was genotype dependent. Higher temperatures reduced pollen tube growth in the style (decrease for 17% in 2009 and for 9% in 2010) and fertilization percentage (decrease for 9% in 2009 and for 8% in 2010) by increasing the time required for pollen tubes to reach the base of the style or the ovule. Due to faster pollen tube growth, the percentages of pollen tube growth and fertilization were significantly higher in cross-pollinated flowers (94.9% in 2009 and 70.9% in 2010 for pollen tube growth ; 58.9% in 2009 and 51.4% in 2010 for fertilization) than in self-pollinated flowers (35.4% in 2009 and 59.6% in 2010 for pollen tube growth ; 19.3% in 2009 and 39.1% in 2010 for fertilization). The results of our study support the model that the self-incompatibility level in olive is regulated by temperature because differences in self-fertilization percentage were observed between ‘Oblica’ trees outside and inside the polyethylene cages.

Olive orchard productivity largely depends on the choice of planted cultivars and their pollination needs. Orchard designs in Croatia are changing because a number of valuable foreign olive cultivars, mostly Italian, have been introduced in this region in the last 30 years. The compatibility relationships of introduced cultivars with autochthonous cultivars are unknown. With the objective of studying reproductive behavior of the most important Croatian cultivars (Drobnica, Lastovka, Levantinka, and Oblica) and their cross-pollination to recently introduced Italian cultivars Leccino and Pendolino, initial and final fruit set in self-pollination versus cross-pollination and free pollination were compared during three flowering seasons. Experiments were conducted in three different orchards (Kastela, Mravince, and Brac) to identify the effect of the environment on reproductive behavior of olive cultivars. The differences of fruit set in five olive cultivars after tested pollination treatments appeared at the time of initial fruit set. Increased final fruit set under cross-pollinations was observed when compared with self-pollination for all olive cultivars in all experimental orchards. In the Mravince orchard, a positive response to cross-pollination was consistent, and fruit set increased under cross-pollination in all cultivars and years with the exception of ‘Levantinka’ in which no significant differences were noticed between self-pollination treatment and cross-pollination treatments in 2005. Variable self-fertility behavior from season to season was found for tested cultivars. A self-incompatibility index (ISI) higher than 0.1 was recorded for ‘Levantinka’ in all experimental years and, therefore, classified it as a partially self-incompatible cultivar. Self-incompatibility response was observed for ‘Lastovka’. The positive response to cross-pollination over self-pollination only in some experimental years classified ‘Drobnica’, ‘Leccino’, and ‘Oblica’ as partially self-incompatible. Results obtained from this study indicated that pollination efficiency is strictly combination-specific. The Italian cultivar, Leccino, was a successful pollen acceptor and pollenizer of most Croatian cultivars. Reciprocal high success in cross-pollination was recorded for ‘Levantinka’ and ‘Oblica’. In the Mravince orchard, ‘Lastovka’, ‘Leccino’, and ‘Oblica’ were efficient pollenizers of ‘Levantinka’ where the simultaneous flowering period was in accordance with their cross-compatibility. ‘Levantinka’ was a good pollenizer for ‘Lastovka’ in the Mravince orchard, and both cultivars entered into the flowering period earlier than other studied cultivars, which was not the case in the other two orchards. The variations in flowering timing among orchards were a consequence of differences in environmental conditions. According to the high fruit sets recorded in ‘Oblica’ after pollination with ‘Leccino’ or ‘Levantinka’, an increase in tree productivity of the acceptor cultivar is expected in the presence of selected pollenizers in all olive-growing regions.

Pollen performance under in vitro conditions is related to its ability to set seeds and fruits following in vivo pollination. Two in vitro tests usually used for pollen viability and germination capacity evaluation were compared in this study. Pollen performance of six sweet cherry cultivars ('Bing', 'Gomilička', 'Hedelfinger', 'Lambert', 'Stonska' and 'Tugarka') was tested using in vitro pollen germination test and fluorochromatic reaction test (FCR). Pollen germination success tested on germination medium consisted of 15% sucrose + 1% agar after 24h of incubation ranged from 22.4% ('Tugarka') to 61.4% ('Hedelfinger'). The highest germinations among the tested cultivars were recorded for 'Hedelfinger' after 2h and 24h. Significant differences among the pollen viability and germination success were recorded for all tested cultivars except for 'Hedelfinger'. Higher pollen viability was found with FCR for 'Tugarka' (83.8%) and Bing (82.6%) compared to 'Gomilička' (71.7%), 'Lambert' (69.9%), 'Hedelfinger' (69.3%), and 'Stonska' (64.6%). Pollen germination test showed lower viability of tested pollen than FCR.

Olive (Olea europaea L.) is the major fruit tree in the Mediterranean region, often grown in locations where plants are exposed to increased salinity. To determine the effect of NaCl on shoot and root growth, dry matter allocation, leaf Na+ and K+ concentration, electrolyte (EL) and K+ leakage (KL), seven olive cultivars of different origins were grown in nutrient solution containing 0, 33, 66, 100 or 166 mM NaCl for three months. The general effect of salinity was linear and quadratic decrease of observed plant growth parameters. Different responses of tested cultivars to applied levels of salinity were found for stem dry weight, shoot length and number of leaves. As salinity increased, growth of ‘ Manzanillo’ declined sharply, whereas ‘ Frantoio’ was the most tolerant to growth reduction in most of the observed growth parameters. Allometric analysis showed that biomass allocation under salinity stress was similar in all cultivars, but the slope between shoot weight and total plant weight decreased as salinity increased. Since the higher allocation in roots was not found, it seems that salinity only slowed the above ground plant canopy growth. Sodium concentration in leaves of all cultivars increased as salinity increased with the highest increment reached when the salinity of nutrient solution was raised from 100 to 166 mM NaCl. Significant differences among genotypes were found in leaf Na+ and K+ concentration and K+:Na+ ratio, but they were not related to the growth rate. Generally, ‘ Frantoio’ and ‘ Oblica’ accumulated less Na+ and were able to maintain higher K+:Na+ ratios as compared to other genotypes. Electrolyte leakage and KL linearly increased with increasing salinity and the magnitude of the response depended upon the olive cultivar.

SUMMARYWatermelon is a crop with a high water demand and is frequently grown under conditions of higher than normal root-zone salinity. In the present study, seedlings of watermelon (cv. Fantasy, Citrullus lanatus (Thunb.) Matsum & Nakai) were grown either ungrafted or grafted on three rootstocks: Strong Tosa, S1 (both Cucurbita maxima×Cucurbita moschata), or Emphasis (Lagenaria siceraria). All the plants were exposed to an NaCl-induced salinity stress (electrical conductivity, EC=2·2, 4·0, or 6·0 dS/m). The vegetative growth of all the plants substantially reduced after 2 weeks of exposure to 6·0 dS/m; however, growth of the plants grafted on Strong Tosa reduced less than that of the others. The leaf water content and specific leaf area (SLA, m2/g) decreased with an increasing salinity in grafted plants, but not in ungrafted plants. Salinity induced an increase of superoxide dismutase (SOD) activity in grafted plants up to two-fold depending on the rootstock, whereas it had no effect on this enzyme activity in ungrafted plants. Leaf Na+ concentration increased with increasing salinity in ungrafted and S1 grafted plants, whereas there was no significant leaf Na+ accumulation in Emphasis and Strong Tosa grafted plants. Leaf K+ concentration was affected by the rootstock but not by salinity, thus, the ability to keep a high K+/Na+ ratio was achieved mainly by limiting leaf Na+ concentration. The rootstock determined the leaf Cl− accumulation, with lower overall concentrations found if plants were grafted on the S1 rootstock than on Emphasis or ungrafted plants. Salinity significantly decreased the leaf NO3− concentration on Emphasis grafted plants only, while the NO3−/Cl− ratio was reduced in all the rootstocks. The capacity of Strong Tosa to withstand salt stress better than other tested rootstocks was probably due to the ability to induce anatomical adaptation (SLA) and SOD activity in response to salt stress, and also to the efficiency of Na+ exclusion from the shoot.

Vijek ekonomskog korištenja masline je oko 50 godina. Nakon tog razdoblja bilo bi potrebno provesti obnovu stabala. Osim obnove koja se provodi zbog starosti stabala, maslinu je potrebno obnavljati i zbog oštećanja nastalih požarom ili studeni. Postoje tri modela obnove oštećenog stabla: model obnove na panj, model obnove u krošnju i model obnove pojačanom rezidbom. Koji model će se primijeniti ovisi o razlogu zbog kojeg provodimo obnovu i o stupnju oštećenja stabla. Radi neravnoteže između korjenovog sustava i nadzemnog dijela obnovljena stabla imaju intenzivan rast te tako veoma brzo dolaze u produktivnu dob. U starim nasadima masline pri provedbi zahvata obnove potrebno je obaviti nadosadnju drugim sortama i sortama oprašivačima. Za kvalitetnu obnovu potrebno je u obnovljenim nasadima provoditi pojačanu ishranu i redovitu agrotehniku obnovljenih stabala., Period of economic exploitation of olive-growes is about 50 years. After that period it would be necessary to realise the regeneration of tree. Beside regeneration of old age olive trees it is also necessary to conduct regeneration of trees damaged by fire or cold. There are three models of tree regeneration: regeneration model on trunk, regeneration model of tree top and regeneration model by intensive cutting. The model that should be applied is dependent on reason that caused necessity for regeneration and also dependent on stage of tree damage. Imbalance between root system and above-ground part of plant causes intensive growth of regenerated tree and fast transition to reproductive period. In old olive-growes additional-planting with another cultivars and pollinators is recommended. For quality final regeneration of olive trees intensified application of plant nutrition and regularly agrotechnics is required.

Uspjeh ukorijenjivanja reznica masline ovisi o različitim čimbenicima od kojih su najvažniji zdravstveno stanje matičnog stabla, vrijeme uzimanja reznica, debljina reznice, primjenjena tehnologija ukorjenjivanja te vrsta i koncentracija stimulativnog sredstva. U istraživanju je primjenjena tehnologija ukorjenjivanja zelenih reznica metodom "mist propagation". Reznice su uzimane u tri vremenska razdoblja, početkom mjeseca srpnja, kolovoza i rujna. za stimulaciju ukorjenjivanja korištena je IBA (Indole-3-butyric acid) u dvije koncentracije. Prema dobivenim rezultatima najveći uspjeh ukorjenjivanja postignut je s reznicama uzetim početkom mjeseca rujna.