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Olive (Olea europaea L.) fruit and derived products play a pivotal role in the Mediterranean diet, to which they contribute their gastronomic value and their health-promoting properties. The fruit cuticle constitutes the interface between the plant and the surrounding environment, and it modulates relevant traits such as water loss, mechanical resistance, and susceptibility to pests and rots. Hence, a better knowledge of fruit cuticle properties and the impact thereupon of agronomic factors could help improving olive grove management. In this work, time–course changes in fruit cuticle yields and composition were assessed during the on-tree ripening of 'Arbequina' olives obtained from irrigated or rain-fed trees grown at a commercial grove located in El Soleràs (Catalonia, Spain), where low annual rainfall occur together with cold winters and hot dry summers. Significantly higher wax contents were observed for rain-fed than for irrigated fruits, both in relative (% over total cuticle) and in absolute terms (from 231 to 840 µg cm−2 and from 212 to 560 µg cm−2, respectively, contingent upon the maturity stage), in agreement with their proposed role as a barrier against water loss. Compositional differences in cuticular waxes and in cutin monomers were also detected between irrigated and rain-fed olives, with major changes involving significantly higher loads per surface area of triterpenoids and ω-hydroxy fatty acids in the latter. In contrast to the load and composition of cuticular wax, no apparent impact of irrigation was observed on either total cuticle yields or cuticle thickness. [ABSTRACT FROM AUTHOR]

The olive tree (Olea europaea L.) has been cultivated around the Mediterranean basin since ancient times, 'Arbequina' being one of the most widely grown varieties. To improve the knowledge on ripening-related firmness changes in olive fruit, cell wall metabolism was studied in irrigated and rain-fed 'Arbequina' olives grown at 'Les Garrigues', a Protected Designation of Origin (PDO) in Catalonia (NE Spain) where harsh environmental conditions occur during fruit development. Fruit samples were picked periodically from September to January. Time-course dynamics of firmness loss during maturation were characterised by a first phase of rapid firmness loss followed by a second phase of moderate change. Compositional changes in cell walls and related enzyme activities were studied in fruit samples. Fruit firmness was significantly higher in rain-fed than in irrigated olives. Neutral sugar loss, an early event in ripening-related cell wall modifications, was lower in rain-fed samples, which, moreover, retained higher uronic acid amounts in the chelator-soluble fraction, thus resulting in attenuated firmness loss in these fruits. [ABSTRACT FROM AUTHOR]

Despite the importance of flowering for fruit formation, it has been considered very little in breeding programs involving fruit species, including olives. We evaluated the principal morphological flower-quality components in the olive cultivars, 'Arbequina' and 'Picual', and in the progenies of their crosses. Wide ranges of variation were obtained for all the inflorescence traits and ovary tissue sizes. An analysis of variance indicated that the residual error was the main contributor to the inflorescence traits, except for the number of perfect flowers, underlining the need to evaluate adequate numbers of inflorescences for accurate measurements of these traits. However, the high repeatability obtained for the inflorescence traits suggests that simple evaluation procedures could be accurate enough for genotype characterization. The average values for 'Arbequina' were in the upper range for all the traits; the opposite occurred for 'Picual', and the values for most of the progenies were intermediate. No significant differences between the maternal and paternal effect on inheritance were found. Some interesting transgressive segregants showed a higher flower number, greater ovary and mesocarp size, or percentage of ovaries with all four fully developed ovules. The correlations among the parameters may have reflected a relatively consistent distribution of the ovaries' structural components and a close relationship between the ovaries and their mesocarp growth. [ABSTRACT FROM AUTHOR]

BACKGROUND Tocopherols and sterols are minor components of virgin olive oils that contribute to oil quality. Based on observations at different geographical locations, it has been suggested that environmental temperature during fruit growth affects tocopherol and sterol oil concentrations in olive fruit. However, controlled experiments have not been conducted to directly assess their responses to temperature. In this study, a manipulative experiment using open‐top chambers (OTCs) was performed in the field to evaluate the responses of these oil components to a moderate air temperature increase during oil accumulation in young trees of two olive cultivars (Arbequina, Coratina). The two temperature levels in the OTCs were a control about 1 °C above ambient temperature (T0) and a heated treatment (T+) with a target temperature of 4 °C above T0. RESULTS: Total tocopherol and sterol oil concentrations in olive fruit were generally higher in the T+ temperature treatment than in the control at the end of the oil accumulation period. The increase in total tocopherols in T+ appeared to be related to a decrease in fruit oil concentration with heating. Individual sterols showed both significant increases and decreases due to T+, and some differences in response occurred between the two cultivars. CONCLUSION: These findings provide evidence that growth temperature affects tocopherol and sterol oil concentrations in olive fruit at the end of the oil accumulation period. Cultivars should be carefully chosen for new olive‐growing regions, and the results could be relevant for global warming scenarios in existing growing regions. © 2021 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Olive (Olea europaea L.) fruit and derived products play a pivotal role in the Mediterranean diet, to which they contribute their gastronomic value and their health-promoting properties. The fruit cuticle constitutes the interface between the plant and the surrounding environment, and it modulates relevant traits such as water loss, mechanical resistance, and susceptibility to pests and rots. Hence, a better knowledge of fruit cuticle properties and the impact thereupon of agronomic factors could help improving olive grove management. In this work, time–course changes in fruit cuticle yields and composition were assessed during the on-tree ripening of ‘Arbequina’ olives obtained from irrigated or rain-fed trees grown at a commercial grove located in El Soleràs (Catalonia, Spain), where low annual rainfall occur together with cold winters and hot dry summers. Significantly higher wax contents were observed for rain-fed than for irrigated fruits, both in relative (% over total cuticle) and in absolute terms (from 231 to 840 µg cm−2 and from 212 to 560 µg cm−2, respectively, contingent upon the maturity stage), in agreement with their proposed role as a barrier against water loss. Compositional differences in cuticular waxes and in cutin monomers were also detected between irrigated and rain-fed olives, with major changes involving significantly higher loads per surface area of triterpenoids and ω-hydroxy fatty acids in the latter. In contrast to the load and composition of cuticular wax, no apparent impact of irrigation was observed on either total cuticle yields or cuticle thickness.

The olive tree (Olea europaea L.) has been cultivated around the Mediterranean basin since ancient times, ‘Arbequina’ being one of the most widely grown varieties. To improve the knowledge on ripening-related firmness changes in olive fruit, cell wall metabolism was studied in irrigated and rain-fed ‘Arbequina’ olives grown at ‘Les Garrigues’, a Protected Designation of Origin (PDO) in Catalonia (NE Spain) where harsh environmental conditions occur during fruit development. Fruit samples were picked periodically from September to January. Time-course dynamics of firmness loss during maturation were characterised by a first phase of rapid firmness loss followed by a second phase of moderate change. Compositional changes in cell walls and related enzyme activities were studied in fruit samples. Fruit firmness was significantly higher in rain-fed than in irrigated olives. Neutral sugar loss, an early event in ripening-related cell wall modifications, was lower in rain-fed samples, which, moreover, retained higher uronic acid amounts in the chelator-soluble fraction, thus resulting in attenuated firmness loss in these fruits.

Os objetivos deste trabalho foram estabelecer in vitro as cultivares de oliveira 'Arbequina' e 'Maria da Fé' e avaliar a influência das tampas com membranas permeáveis a gases na morfogênese in vitro dessas cultivares. Inocularam-se segmentos nodais com gemas previamente descontaminadas pelo protocolo aqui desenvolvido. Utilizaram-se o delineamento inteiramente casualizado (DIC) em esquema fatorial 2³, duas cultivares; dois meios de cultura OM (Olive medium) (OM + 20 µM de zeatina [1]; e OM + 20 µM de zeatina + 10 µM de GA3 [2]); dois tipos de vedação (tampa rígida sem orifício e com membrana porosa) com cinco repetições/ tratamento; e a unidade experimental constituída por quatro tubos de ensaio. Avaliaram-se: a porcentagem de contaminação total; a porcentagem de contaminação fúngica e bacteriana; o número de gemas intumescidas; o número de brotos; e a porcentagem de oxidação. Aos 30 dias de cultivo, constatou-se a contaminação de 15% e 8,8% dos explantes de 'Arbequina' e 'Maria da Fé', respectivamente. Em 'Arbequina', 33,3% e 66,7% ocorreram por contaminação fúngica e bacteriana, respectivamente. Em 'Maria da Fé', 28,6% e 71,4% decorreram de contaminação fúngica e bacteriana, respectivamente. O número de gemas foi superior (pThe objectives of this work were to establish cultivars of Olea europaea L., namely 'Arbequina' and 'Maria da Fé', and to evaluate the influence of gas exchange on in vitro morphogenesis of these cultivars. Under aseptic conditions, single-bud nodal segments were previously decontaminated using disinfestation protocol developed in this work. The treatments followed a completely randomized design, in a 2³ factorial scheme: two cultivars and two olive (Olive medium) culture media (OM) (OM + 20 µ M zeatin [1]; and OM + 20 µ M zeatin + 10 µM GA3 [2]); and two types of sealing (rigid lid without orifice and porous membrane) in five repetitions/treatment. The experimental unit consisted of four tubes. The following parameters were assessed: percentage of total contamination; percentage of fungal and bacterial contamination; number of explants with swollen buds; number of axillary buds, and oxidation percentages. At 30 days of cultivation, the total contamination indexes of 15% and 8.8% were recorded for 'Arbequina' and 'Maria da Fé', respectively. For bacterial and fungal contamination percentages, respectively, 'Arbequina' had 33.3% and 66.7%, whereas 'Maria da Fé' presented 71.4% and 28.6%. Regarding the number of responsive cultures showing swollen buds, there was no difference between cultivars when rigid lids without porous membranes were used. However, lids with porous membranes led to statistically superior values for 'Arbequina' as compared to 'Maria da Fé'. For the number of shoots, culture medium 1 was statistically superior to 2. There was no statistical difference for oxidation percentages among treatments. Thus, because of the low level of contamination, it is suggested to use the disinfestation protocol developed in this work. In addition, the use of culture medium 1 and lids with porous membranes did favoured further development of axillary buds into plants.

Highlights: [•] Significantly greater KUE values were found in the T3 and T4 treatments. [•] ‘Koroneiki’ was the most K-efficient cultivar in the T3 and T4 treatments. [•] K concentration affected the plant growth of ‘Kalamon’ and ‘Arbequina’. [•] Greater stomata opening were recorded in the highest (T4) treatment. [•] The photosynthetic rate of ‘Koroneiki’ was not higher in the T4 treatment. [ABSTRACT FROM AUTHOR]

A comparative study was conducted to evaluate the influence of seven different levels of irrigation applied to 'Arbequina 1-18' olive (Olea europaea L.) trees grown in a super-high-density orchard (1,656 trees/ha) in the Sacramento Valley of California. Water was applied differentially by drip irrigation at rates of 15%, 25%, 40%, 57%, 71%, 89%, and 107% evapotranspiration (ETc) in 2002, and 28%, 33%, 55%, 74%, 93%, 117%, and 140% ETc in 2003. Each treatment was replicated three times. Olives were harvested on two different dates each year from each of 21 plots. Three of four harvest dates showed a decrease in maturity index with increasing irrigation levels. Oils were made from olive samples collected from each plot and analyzed for oil quality parameters. Total polyphenol levels and oxidative stability decreased as the trees received more water, especially for the three lowest irrigation treatment levels in 2002, but few differences were noted between treatments in 2003 when all the trees were irrigated more heavily. Average oxidative stability was correlated very closely with total polyphenol content with r² = 0.98 in 2002 and 0.94 in 2003. In 2002, free fatty acid levels increased and peroxide levels were unchanged, but in 2003, free fatty acid levels were unchanged and peroxide levels decreased in treatments receiving more water. Saturated fatty acids did not significantly change in 2002, due to tree irrigation level. The mono-unsaturated fatty acid levels and oleic-linoleic relationship declined while poly-unsaturated fatty acid levels increased in 2002 with increased irrigation. In 2003, there was no notable difference in the ratio of mono to poly unsaturated fatty acid levels. The individual fatty acid most consistently affected by more irrigation water was stearic, which decreased in both years. Total sterol content (mg·kg-1), percentages of cholesterol and erythrodiol were significantly influenced by tree irrigation levels, but increased in one year and either decreased or were unchanged the next. Oil sensory properties of fruitiness, bitterness, and pungency all declined in oils made from trees receiving more water. The lowest irrigation levels produced oils that were characterized by excessive bitterness, very high pungency, and woody, herbaceous flavors. Intermediate irrigation levels (33% to 40% ETc) produced oils with balance, complexity, and characteristic artichoke, grass, green apple, and some ripe fruit flavors. Higher irrigation levels lowered oil extractability and produced relatively bland oils with significantly less fruitiness and almost no bitterness or pungency. [ABSTRACT FROM AUTHOR]

The chemical composition and radical-scavenging activity of wood samples from 10 main Spanish olive cultivars were studied. The wood samples were collected during the pruning works from trees growing under the same agronomical and environmental conditions. The 10 ethyl acetate extracts were submitted to HPLC-DAD/ESI-MS analysis to determine the phenolic constituents. Seventeen compounds were identified (10 secoiridoids, 3 lignans, 2 phenol alcohols, 1 iridoid, and 1 flavonoid) by comparison with authentic samples. Significant quantitative and qualitative differences were found among olive cultivars. The lignan (+)-1-hydroxypinoresinol 1-O-β-d-glucopyranoside was the major compound in all olive cultivars, except in cultivars 'Farga' and 'Picual'. The multivariate analysis of all data revealed three sets of cultivars with similar compositions. Cultivars 'Gordal sevillana' and 'Picual' had the most distinct chemical profiles. With regard to the radical-scavenging activity, cultivar 'Picual', with oleuropein as the major phenolic, showed the highest activity (91.4 versus 18.6-32.7%).