Search Results (107)

The large and hard olive pit adversely affects oil quality during traditional crushing, as seed- and pit-derived enzymes modify phenolic profiles and volatile compounds. Polyploid breeding offers a potential means to reduce pit size and improve processing traits, yet cultivated olive (Olea europaea L. subsp. europaea) is a strictly diploid species, and natural polyploids have not been previously documented. To evaluate the potential of triploids in olive improvement, we screened seed-derived progeny from multiple cultivars for polyploidy using flow cytometry and chromosome observation. One naturally occurring triploid seedling (‘Olive-3x’) was identified from a mixed lot of open-pollinated seeds. Whole-genome resequencing was used to develop 64 polymorphic InDel markers, and three markers indicated ‘Koroneiki’ as one putative parent of the triploid. Morphological and cytological analyses showed that the triploid exhibited typical polyploid characteristics, including thicker leaves and enlarged epidermal and palisade mesophyll cells compared with diploid controls. These findings provide the first evidence of a naturally occurring triploid in cultivated olive and show that triploids can arise within seed-derived progeny. The identified triploid plant and the developed markers offer useful resources for future studies on olive polyploidy and provide foundational resources for future research on olive polyploidy and cultivar improvement. Full article

Modern olive breeding points to a plant model characterized by low vigour, high productivity, and resistance to biotic and abiotic stresses, all traits required by the intensive and superhigh-density (SHD) systems of olive tree growing. The Italian Don Carlo and FS-17 Favolosa stand out among the new cultivars that are being tested. They were obtained not by breeding but by mass selection from two seedling populations of the Frantoio cultivar (maternal parent). Here, a multidisciplinary approach was used to determine the paternal parent of Don Carlo and FS-17, and then to investigate the inheritance of interesting traits such as fruit cell dimensions and oil content in these cultivars. Microsatellites were applied in phylogeny and kinship analyses, along with two functional markers previously developed on OeACP1 and OeACP2 genes. Ascolana Tenera cultivar was identified as the paternal parent of both new cultivars. This result was also supported by the analysis of the self-incompatibility group of the new cultivars and their most likely paternal parents. Light and electron microscopy [Cryo Scanning Electronic Microscopy (CRYO-SEM), Electronic Scanning Microscopy (E-SEM), and Transmission Electron Microscope (TEM)] techniques were used to analyze the fruit development concerning oil accumulation. Significant differences in cuticle thickness, size and shape of mesocarp and exocarp cells, and oil content were detected among cultivars. Our results suggested that the rearrangement of the traits studied led to an improved progeny compared to the parents. FS-17 exhibited an oil storage efficiency higher than Frantoio. Don Carlo showed fruit traits and oil content almost intermediate between the parents, making it a dual-purpose cultivar. Full article

The olive tree (Olea europaea L.), a cornerstone of Mediterranean agriculture, is widely recognized for its inherent drought tolerance. However, the increasing frequency and intensity of water deficit events driven by climate change are challenging its growth, productivity, and long-term sustainability. This review synthesizes current knowledge on the morphological and phenological adaptations of olive trees to water stress. In fact, under drought conditions, olive trees develop a suite of structural and anatomical adjustments that collectively enhance water-use efficiency and help maintain plant water status. These adjustments include reduced leaf area, thickened cuticles, mesophyll rearrangements, remodeling of xylem vessel architecture, and reinforced root systems. These morpho-anatomical responses influence phenology, through changes in the timing and duration of key phenological stages, leading to reduced flower induction, lower flowering intensity, decreased fruit set, and overall lower yields, while the most pronounced effects are observed in sensitive cultivars. Among all stages, flowering is the most vulnerable to water deficit, while pit hardening and fruit development show comparatively more tolerance. The combination of morphological, anatomical, and phenological responses could provide a mechanistic elucidation of drought tolerance variability within olive cultivars. Understanding this interplay is likely to offer valuable criteria in selecting and breeding resistant varieties, thus ensuring productive and sustainable olive cultivation under increasingly severe climatic conditions. Full article

Major historic olive tree cultivars around the Mediterranean originate from the Jordan area and possess a proven abiotic stress tolerance; however, they were unexplored from the diversity perspective. Therefore, historic olive tree accessions from three northern regions—Irbid (i), Jerash (J), and Ajloun (A)—were analyzed using DNA molecular markers to identify and study their genetic relationships and genetic structure. DNA molecular markers of inter-simple sequence repeats (ISSR) were used. A total of 3150 data entries (859 present and 2291 absent) were generated with fragment sizes ranging from 350 to 2000 bp. Data entries were evaluated with UPGMA and population genetic structure analysis. The results showed that similarity among the investigated sixty-three accessions ranged from 9% between J14 and i20 up to 100% between ‘J11’ and ‘J12’ and between A8 and A9. The discriminating power values for ISSR_807, ISSR_810, and ISSR_825 were 0.70, 0.61, and 0.83, respectively. A generated dendrogram showed ten major clades, while the genetic structure could resolve four unique genetic pools: one for Irbid, one for Jerash, and two for Ajloun. In addition, analysis of 19 phenotypic parameters covering leaf, fruit, stone, and flesh was able to confirm the molecular data. Phenotypic and ISSR data were analyzed using PCA, cluster, and Mantel tests. ISSR markers showed clear genetic differentiation among groups, whereas phenotypic traits displayed lower variation but a significant correlation with molecular diversity. Promising accessions with either pure or admixture genetic makeup were identified. The resolved genetic structure of the investigated historic olive accessions would open new frontiers for olive breeding and utilization, helping to overcome current production challenges and climate change limitations. Full article

Oleuropein (OLE), as the main effective active component in olive leaves, is a natural cyclic ether terpene polyphenolic compound found in plants of the genus Olea. It has antioxidant, anti-inflammatory and anti-apoptotic properties, and can reduce damage caused by reactive oxygen species. These characteristics indicate that it can enhance the maturation rate of oocytes and the developmental capacity of embryos—two key indicators in animal breeding. This study evaluated the effects of OLE on the in vitro maturation and early embryonic development of sheep oocytes. 20 μM OLE has the best promoting effect on the maturation rate of oocytes, and 30 μM OLE has the best increasing effect on the blastocyst rate. Compared with the control group, glutathione (GSH) level and mitochondrial membrane potential (MMP) level were significantly increased, ROS level was significantly decreased, the expression of antioxidant genes SOD1 and GPX3 was significantly elevated, and the expression of anti-apoptotic gene BCL2 was significantly elevated in the experimental group. In addition, during the in vitro development stage of early embryos, the expression level of the embryo development-related gene OCT4 significantly increased. The study has shown that OLE can effectively alleviate oxidative stress during in vitro culture, increase oocyte maturation rate and promote embryo development. Full article

Climate change poses serious challenges to Mediterranean crops such as the olive tree (Olea europaea L. subsp. europaea), underscoring the need for cultivars with improved drought tolerance and disease resistance. This study investigates variability in leaf and wood traits among Moroccan and introduced olive cultivars and their crossbreed genotypes grown under similar conditions. Specifically, we assessed (1) variation in key functional traits, (2) the effects of crossbreeding combinations, and (3) trait syndromes shaped by selection. Results showed substantial intraspecific variation in leaf traits, including specific leaf area (SLA), specific leaf water content (SLWC), stomatal size (SS), and density (SD), indicating diverse strategies for resource use and plasticity. Crossbreed genotypes generally displayed higher SLWC and lower SLA, reflecting adaptation to water stress. Wood traits, particularly vessel size (SVS) and number (NVS), also varied, revealing trade-offs between hydraulic efficiency and safety. Notably, an increase in vessel size and hydraulic conductivity was correlated with oil content (OC%), while OC% increased with higher vessel and stomatal densities. Larger stomata increased conductance and fruit growth, while lower SLA was linked to higher yield. Multivariate analysis distinguished two genotype groups, consistent with parental combinations. Overall, crossbreeding generated novel functional diversity that may enhance adaptive potential. These findings highlight the value of integrating functional and anatomical traits into olive breeding programs to improve resilience and productivity under climate change. Full article

Chlorogenic acid (CGA)-rich extracts from Eucommia ulmoides Oliver (CAE) are known for their gut health and antioxidant benefits in livestock. This study examines the effects of CAE supplementation during the peri-implantation period on sow reproductive performance and the gut microbiota. Sixty Dongliao black sows were randomized to receive either no supplementation (control) or CAE at 600 or 2000 mg/kg daily from gestation day −5 through day 15. High-dose CAE intake significantly increased total antioxidant capacity (T-AOC), superoxide dismutase (SOD), catalase (CAT), immunoglobulin A (IgA), and immunoglobulin M (IgM) levels in sow serum but decreased malondialdehyde (MDA) levels. Fecal short-chain fatty acids (SCFAs) also increase significantly. These changes correlate with improved reproductive performance, including a larger litter size, higher numbers of live-born piglets, a greater individual birth weight of live-born piglets, a higher total litter birth weight of live-born piglets, and a lower mortality rate. 16S rRNA sequencing of the fecal microbiota revealed that CAE markedly altered microbial diversity and composition, reducing the abundance of potentially harmful bacteria but increasing the abundance of beneficial bacteria. In conclusion, supplementation with CAE during the peri-implantation phase can reduce oxidative stress, alter the gut microbiota composition, and improve sow reproductive performance, thus potentially increasing breeding farm profitability. Full article

Camellia vietnamensis grows in a unique tropical environment, and its seed oil has a rich aroma. The content of unsaturated fatty acids in C. vietnamensis oil is up to 90%, which can regulate human lipid metabolism and prevent cardiovascular and cerebrovascular diseases. Compared with olive oil, C. vietnamensis oil has a higher content of unsaturated fatty acids. This study used eleven C. vietnamensis cultivars cultivated on Hainan Island. Among the 11 cultivars, “Boao 1” had fruits with the largest vertical diameter of 45.05 mm, while “Haida 1” had fruits with the largest horizontal diameter, single-fruit weight, and fresh 100-grain weight of 53.5 mm, 70.6 g, and 479.01 g, respectively. “Boao 3” had an acid value and peroxide value of 1.59 mg/g and 3.50 mmol/kg, respectively, and its saponification value content was 213.18 mg/g. “Boao 5” had the highest iodine value, 101.86 g/100 g, among the 11 cultivars. The content of unsaturated fatty acids in the seed oil of 11 cultivars ranged from 84.87% to 87.38%. The qRT-PCR results confirmed that “Boao 3” had a higher content of flavonoids and fatty acids than other cultivars. The comprehensive analysis of physiological and biochemical indices showed that the top five cultivars were “Haida 1”, “Boao 3”, “Haida 2”, “Boao 1”, and “Boao 5”. These five cultivars were suitable for large-scale cultivation in tropical regions, such as Hainan Island. This study provided a theoretical basis for the breeding of C. vietnamensis cultivars in tropical regions. Full article

To evaluate animal performance and meat quality, stoned olive cake and linseed were used in an experimental test conducted on thirty-six young Podolian bulls, divided into four groups: the control group (CON), OC group (with olive cake containing a 30% as-fed basis of stoned olive cake), EL group (with linseed containing a 15% as-fed basis of extruded linseed), and OCEL group (with olive cake + linseed containing 20% stoned olive cake and 10% extruded linseed). The results show that olive cake supplementation did not influence performance in vita or the post-slaughter animal measurements (final body weight, DMI, FCR, ADG, carcass weight, dressing percentage, and pH) (p > 0.05); this was not true of the TBARS and color measurements, for which the meat samples showed excellent values (p < 0.001), especially in diets supplemented with olive cake. In conclusion, incorporating olive cake and linseed into the diet of fattening cattle may be a way to utilize a by-product of the olive industry and naturally increase the nutritional value of meat and meat-based products in Mediterranean regions. This would reduce environmental impacts and promote the valorization of this local feed source in alignment with the principles of the circular economy. Full article

Phenolic compounds are important targets in olive breeding due to their health benefits and impact on fruit and oil quality. Fruit phenolic profiling enables efficient screening of large germplasm collections without oil extraction, but environmental variability, especially year-to-year differences, affects their expression. The aim of this study was to assess the genotypic influence on fruit phenolic composition, based on a three-year evaluation of 10 wild olive genotypes and 75 cultivars from an olive core collection. Each genotype was sampled in at least two seasons, with 1 to 3 trees analyzed annually. Variance analysis revealed significant genetic variation among cultivars and notable genotype-by-year interactions for certain phenolics. Broad-sense heritability was generally high for most compounds, although some, such as ligstroside and ligstroside aglycone, showed greater environmental sensitivity. Best linear unbiased predictions (BLUPs) were highly correlated with average relative phenotypic values. Clustering analyses identified strong associations among key phenolic compounds and highlighted distinct metabolic profiles separating wild and cultivated genotypes, reflecting differences in phenolic accumulation patterns. These findings demonstrate the genetic and environmental influences on olive fruit phenolics and provide reliable estimates to support future marker-assisted selection studies aimed at developing useful tools in olive breeding programs. Full article

Olive trees are generally considered a species well-adapted to drought, but the impact of water shortage is of critical importance on olive production. For this reason, developing tolerant cultivars could be an effective strategy to mitigate the impact of drought in the future. Characterizing drought stress tolerance in olive is a complex task due to the numerous traits involved in this response. In this study, plant growth, pressure–volume curves, gas-exchange and chlorophyll fluorescence traits, and stomata characteristics were monitored in nine cultivars to assess the effects of mild and severe drought stress conditions induced by withholding water for 7 and 21 days, respectively, and were compared to a well-watered control treatment. The plant materials evaluated included traditional cultivars, as well as new developed cultivars suited for high-density hedgerow olive orchards or resistant to verticillium wilt. Significant differences between cultivars were observed for most evaluated traits, with more pronounced differences under severe drought conditions. A multivariate analysis of the complete dataset recorded throughout the evaluation period allowed for the identification of promising cultivars under stress conditions (‘Sikitita’, ‘Sikitita-2’, and ‘Martina’) as well as highly discriminative traits that could serve as key selection parameters in future breeding programs. Full article

Flowering represents the most important process in the reproductive stage of fruit trees, including olive trees. Previous studies have demonstrated that the genotype–environment interaction (GEI) has a considerable influence on olive flowering time. This study investigated the GEI and genetic parameters influencing olive flowering phenology in Southwestern China (a non-Mediterranean region), using multi-trait-based stability selection methods. Sixteen olive cultivars from five countries were evaluated over two years in two distinct climatic regions of Southwestern China. Flowering phenology was assessed based on three parameters: full-bloom date (FBD), flowering-period length (FP), and full-bloom-period length (FBP). In the analyses, the best linear unbiased prediction (BLUP) to predict genetic value and genotype + genotype by environment interaction (GGE) biplot methods to visualize and assess stability and performance were employed across four environments. The results showed that genotype, environment, and GEI had highly significant effects on flowering traits, with GEI accounting for 54.12% to 89.62% of the variance. Heritability values were low (0.0589 to 0.262), indicating that genetic factors had limited control over flowering phenology compared to environmental factors. A stability analysis using a mean performance and stability (MPS) index identified genotypes with earlier flowering dates and longer flowering periods. Multi-trait selection using a multi-trait mean performance and stability (MTMPS) index further highlighted six superior genotypes with high performance and stability across environments. The findings emphasize the critical role of environmental factors on olive flowering phenology, highlighting the challenges in breeding for stable flowering traits. This study demonstrates the effectiveness of multi-trait selection methods in identifying genotypes with superior performance and stability under different environmental conditions. These results provide valuable insights for olive breeding programs, particularly in non-Mediterranean regions, suggesting that targeted selection and multi-trait evaluation could enhance the adaptability and productivity of olive cultivars under changing climatic conditions. Full article

The accurate definition of tree growth descriptors is a crucial step in enhancing orchard management, allowing cultivar identification within an orchard and in new genotype selection for breeding programs. In apple, almond, and olive orchards, Terrestrial Laser Scanning (TLS) technologies have been already used to identify different architectural groups, but not in hazelnut yet. This study utilized TLS to investigate the canopy structure of hazelnut trees of four different Italian varieties, with and without leaves. TLS proved to be a sensor capable of collecting three-dimensional data from hazelnut field trials and allowed the definition and selection of hazelnut plant descriptors by morphological traits and morphological indexes. Nineteen descriptors, eight morphologic traits and 11 morphological indexes have been identified as reliable suitable descriptors of hazelnut cultivar and in breeding evaluations, according to Biodiversity, FAO and CIHEAM. Many of the selected descriptors are related to the tree habit, vigour and branching density. Two useful indexes have also been defined: Canopy Uprightness (CU) Index and the Index of Canopy Opening (ICO). The descriptors allowed us to distinguish the four studied hazelnut cultivars based on their growth habit; in particular the cultivar Tonda Gentile delle Langhe showed a growth habit that is a lot different from that of the other ones. Full article

Aroma composition serves as a pivotal quality determinant in table grapes (Vitis vinifera). While the cytochrome P450 enzyme CYP76F14 is implicated in aroma biosynthesis, its functional role in grape berries remains uncharacterized. A comparative analysis of three aroma-distinct cultivars—Muscat type ‘Irsai Oliver’, Neutral type ‘Yanhong’, and Berry-like type ‘Venus Seedless’—revealed cultivar-specific linalool accumulation patterns. ‘Irsai Oliver’ exhibited sustained linalool biosynthesis from the fruit set through to maturity (from Stage 1 to Stage 5), with concentrations peaking at Stage 3 (veraison phase) and remaining elevated until harvest, surpassing the other two cultivars. Transcriptional profiling demonstrated that the CYP76F14 expression exhibited a similar trend with the accumulation of linalool levels, showing a higher expression in ‘Irsai Oliver’ across the developmental stages. A structural analysis identified 12 divergent residues in the ‘Irsai Oliver’ CYP76F14 variant, including E378 and T380 within the conserved substrate recognition site. The site-directed mutagenesis of these residues (CYP76F14-E378G/T380A) reduced the catalytic efficiency by 68–72% compared to the wild-type (in vitro LC-MS/MS assays), confirming their functional significance. This work reveals that cytochrome P450 CYP76F14 mediates the conversion of its substrate linalool in table grape berries, especially of Muscat type grapes, and proposes the CYP76F14 polymorphic variants as molecular markers for aroma-type breeding. The identified catalytic residues (E378/T380) provide targets for enzymatic engineering to modulate the terpenoid profiles in Vitis species. Full article

The genetic diversity of the olive tree (Olea europaea L.) is critical for enhancing crop resilience and productivity under changing climatic conditions. Peru’s southern region, particularly Tacna, hosts over 30 olive cultivars, yet their genetic structure remains poorly characterized. This study aimed to evaluate the morphological and genomic diversity of ten economically important olive varieties cultivated in 15 sectors across Tacna and Jorge Basadre provinces. A total of 92 mother plants were selected for morphological assessment using 25 standardized descriptors. Additionally, genomic DNA was extracted from 30 samples and subjected to genotyping-by-sequencing (GBS). Quality metrics confirmed the efficiency of a modified 6h-DNA extraction protocol. Bioinformatic analysis identified hundreds of thousands of SNPs per variety, with a high transition/transversion ratio (∼2.1), indicating reliable variant calls. Phylogenetic clustering revealed three diversity groups, with the olive cultivars Ascolana and Frantoio exhibiting high genetic variability, and Arbequina and Leccino—also olive cultivars—showing reduced diversity. The integration of phenotypic and genomic data highlights hidden variability and supports informed selection and conservation strategies. These findings provide a genomic baseline for breeding programs and genetic resource management in emerging olive-growing regions such as southern Peru. Full article