Search Results (40)

This study investigates the impact of rootstock selection on the essential oil (EO) composition of clementine mandarin (Citrus clementina Hort. ex Tan.) var. SRA 63 cultivated in southern Greece. EOs were extracted from the peel and leaves of trees grafted on four commonly used rootstocks: Cleopatra mandarin, sour orange, Troyer citrange, and Swingle citrumelo. The GC-MS analysis revealed significant qualitative and quantitative differences in EO profiles across the different rootstock combinations. In peel EOs, limonene was the dominant compound, particularly in trees grafted onto Cleopatra mandarin and Swingle citrumelo, while Troyer citrange favored a more diverse chemical profile rich in oxygenated monoterpenes, sesquiterpenes, and aldehydes. Leaf EOs were characterized by high levels of sabinene, linalool, and limonene, with Swingle citrumelo promoting sabinene production and Troyer citrange enhancing limonene content and sesquiterpene diversity. Sour orange showed an intermediate effect, increasing both compound diversity and abundance. These results underscore the critical role played by rootstock in modulating the biosynthesis of volatile compounds, likely through physiological and molecular interactions with the scion. These findings offer valuable insights into optimizing EO yield and quality in citriculture and support the broader goal of valorizing Citrus by-products through targeted agricultural practices. This research contributes to the implementation of targeted agricultural practices (rootstock choice) for the development of high-value Citrus-based products with specific quality traits. Full article

The valorization of citrus peel byproducts presents a sustainable and innovative approach to reducing food waste while improving the nutritional content of fruit-based products. Citrus peels, a significant byproduct of the fruit juice industry, are abundant in bioactive compounds with recognized health benefits and functional properties, making them particularly suitable for jam production. The global citrus industry generates substantial amounts of waste, with peels accounting for approximately 50% of the total fruit mass. Conventional disposal methods often result in environmental concerns and the underutilization of valuable bioresources. This study aims to investigate the potential of incorporating citrus peel into jam formulations as a means of enhancing their nutritional and functional properties. Jams were prepared using a traditional processing technique (TP) incorporating citrus peel. The experimental jam variants included pomelo peel jam (PPJ), lime peel jam (LiPJ), lemon peel jam (LePJ), clementine peel jam (CPJ), orange peel jam (OPJ), and grapefruit peel jam (GPJ). All jam samples were subjected to comprehensive analyses, including assessments of chemical composition, total soluble solids (TSSs), titrable acidity (g/100 g acid citric), macro- and microelement contents, total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activity using the FRAP assay. The study revealed high levels of biologically active compounds, such aspolyphenols, flavonoids, and vitamin C, in the jams, highlighting their antioxidant properties and potential health benefits. Among the jams, lemon peel jam (LePJ) exhibited the highest antioxidant activity and polyphenol content, making it a superior choice in terms of functional benefits. In terms of sensory analysis, orange peel jam (OPJ) was the most favored by consumers, demonstrating its high acceptability and potential for market success. Full article

The Citrus clementina (citrus) plant produces various phytohormones due to the significant involvement of the carotenoid cleavage oxygenase (CCO) gene family in its growth and development. CCO genes can be divided into two main categories: NCED (9-cis-epoxy carotenoid dioxygenase), responsible for abscisic acid (ABA) production, and CCD (carotenoid cleavage dioxygenase), involved in pigment and strigolactone formation. To better understand the roles and positions of CcCCO gene members in relation to these hormones, researchers analyzed the clementine genome. To identify their structural features, they employed phylogenetic analysis, protein interactions, localization, structure, miRNA targets, evolutionary analysis, and transcriptome studies. The study revealed the presence of 15 CcCCO genes, including 11 NCED and 4 CCD genes, scattered across various chromosomes, with the majority located in chloroplasts. Promoter sequencing analysis indicated the presence of different cis-regulatory elements that likely interacted with phytohormones, such as auxin and abscisic acid among others. Notably, two genes, CcNCED1 and CcNCED3, were significantly expressed among the CCO genes, and these were found to be expressed during stress and played a crucial role in enabling optimal plant development. Furthermore, a comprehensive genome-wide comparison of CCO genes in C. Clementine and Arabidopsis thaliana models was conducted to understand their functional characteristics. This research provides a solid foundation for further exploration of the unique attributes of the C. clementina plant, contributing to a deeper understanding of its growth and development processes. Full article

This paper presents the influence of natural extracts obtained from Levisticum officinale and Citrus x clementine on the corrosion of carbon steel in a 3.5% NaCl solution. We started from dried leaves of Levisticum officinale and Citrus x clementine peel in order to prepare several extracts in a 50%:50% (v:v) water/ethanol solution and in analytical-grade ethanol. Several electrochemical techniques, such as open circuit potential monitoring, electrochemical impedance spectroscopy and potentiodynamic polarization, were employed in order to investigate the influence of the synthetized extracts on the corrosion of carbon steel. The aggressive solution that the corrosion tests were performed in was a 3.5% NaCl solution modified with different amounts of the extracts. The electrochemical tests performed in order to determine the influence of the Levisticum officinale leaf and Citrus x clementine peel extracts showed that these extracts may be employed as natural corrosion inhibitors for carbon steel in a 3.5% NaCl solution, achieving inhibiting efficiencies up to 87.8%, in the case of the Levisticum officinale extracts. Full article

Citrus is one of the world’s most important and widely produced fruit crops, with over a 100 million metric tons harvested from nearly 10 million hectares in 2023. Challenges in crop maintenance, production, and fruit quality necessitate developing new traits through Agrobacterium-mediated genetic transformation. While a few Agrobacterium strains (EHA105, GV3101, LBA4404) are known to transform citrus, many wild strains remain untested. We screened forty-one wild-type Agrobacterium strains isolated from various woody species and identified five capable of DNA transfer into citrus cells. Strain 1D1416 demonstrated the highest transient transformation frequency in Carrizo epicotyl explants (88%), outperforming the control EHA105 (84%) with comparable shoot regeneration rates (32% and 42%, respectively). Notably, 1D1416 exhibited no overgrowth and had the lowest necrosis and mortality rates in transformed tissues. It efficiently transferred the DsRed gene and induced galls in mature tissues of Mexican lime (70%), lemon (48%), Washington navel orange (25%), and clementine (6%). Genome sequencing of 1D1416 allowed for the disarming of the native T-DNA and addition of GAANTRY technology. This novel strain, combined with an optimized transformation procedure, make it a valuable tool for advancing citrus transformation. Full article

In this study, the effect of the antioxidant extract from lemon by-products (Citrus × Limon L.) integrated into an edible alginate-based coating was evaluated to preserve the storage quality of ready-to-eat Clementine (Citrus × Clementina) fruits. The effects of different coatings (1.5% of alginate and 1.5% of alginate + 2–4% of lemon by-product extract) were assessed by the physical, chemical, microbiological, sensorial, and structural analyses of ready-to-eat Clementine fruits stored for 21 d at 4 °C. Ready-to-eat Clementine fruits coated with alginate and extract from lemon by-products showed greater levels of polyphenols, flavonoids, antioxidant activity, and organic acids. A microbiological analysis revealed the dose-dependent effect of the extract to contrast the growth of mesophilic bacteria, yeast, and molds during storage. A sensory analysis confirmed that the enriched coating improved the visual, structural, and olfactory parameters until the end of storage. The evidence in this study proves that an antioxidant extract from lemon by-products is a great sustainable treatment to preserve ready-to-eat fruits. Full article

Acute Lung Injury (ALI) is a life-threatening syndrome that has been identified as a potential complication of COVID-19. There is a critical need to shed light on the underlying mechanistic pathways and explore novel therapeutic strategies. This study aimed to examine the potential therapeutic effects of Citrus clementine essential oil (CCEO) in treating potassium dichromate (PDC)-induced ALI. The chemical profile of CCEO was created through GC–MS analysis. An in vivo study in rats was conducted to evaluate the effect of CCEO administrated via two different delivery systems (oral/inhalation) in mitigating acute lung injury (ALI) induced by intranasal instillation of PDC. Eight volatile compounds were identified, with monoterpene hydrocarbons accounting for 97.03% of the identified constituents, including 88.84% of D-limonene. CCEO at doses of 100 and 200 mg/kg bw exhibited antioxidant and anti-inflammatory properties. These significant antioxidant properties were revealed through the reduction of malondialdehyde (MDA) and the restoration of reduced glutathione (GSH). In addition, inflammation reduction was observed by decreasing levels of cytokines tumor necrosis factor-α and tumor growth factor-β (TNF-α and TGF-β), along with an increase in phosphatidylinositide-3-kinase (PI3K) and Akt overexpression in lung tissue homogenate, in both oral and inhalation routes, compared to the PDC-induced group. These results were supported by histopathological studies and immunohistochemical assessment of TGF-β levels in lung tissues. These findings revealed that CCEO plays an integral role in relieving ALI induced by intranasal PDC and suggests it as a promising remedy. Full article

Low-temperature stress is an important limiting factor affecting citrus growth and fruit yields. Therefore, increasing citrus cold stress tolerance may enhance the growth, yield, and quality of citrus production in marginal areas. The objective of this study was to determine the efficacy of silicon (Si) fertilizer application on cold-tolerance enhancement in citrus. Two citrus cultivars (Delta and Nules) were subjected to Si fertilization (control, 1000 mg L⁻¹) and cold-stress temperature treatments (control and 0 °C for 72 h) using a 2 × 2 × 2 factorial treatment structure with six replications. Leaf gas exchange and chlorophyll fluorescence parameters, such as net photosynthetic rate (A), stomatal conductance (g_s), transpiration rate (Tr), internal CO₂ concentration (C_i), intrinsic water-use efficiency (iWUE), minimal fluorescence (F_o), maximum fluorescence (F_m), maximum quantum efficiency of PSII primary photochemistry of dark-adapted leaves (F_v/F_m), maximum quantum efficiency of PSII primary photochemistry of dark-/light-adapted leaves (F’_v/F’_m), electron transport rate (ETR), non-photochemical quenching (NPQ), and the relative measure of electron transport to oxygen molecules (ETR/A), were measured. The application of Si drenching to trees that were subsequently exposed to cold stress reduced g_s, Tr, and C_i but improved iWUE and F_o in both cultivars compared to the Si-untreated trees. In addition, specific adaptation mechanisms were found in the two citrus species; NPQ and ETR were improved in Si-treated Valencia trees, while A, F_m, and ETR/A were improved in Clementine trees under chilling stress conditions. The current research findings indicate the potential of Si application to enhance cold stress tolerance in citrus, which can provide a strategy for growing citrus in arid and semi-arid regions that may experience cold stress. Overall, after the application of silicon drenching, the cold-sensitive citrus Valencia cultivar became as cold-tolerant as the cold-tolerant Clementine cultivar. Full article

Ready-to-eat fresh fruit have an increasing presence in international markets due to their convenience and health benefits. However, these products are highly perishable and efficient technologies to increase their shelf life are needed. In the present research, different citrus fruit species and cultivars from organic farming were assessed to obtain enzymatically peeled citrus segments. The best results in terms of segment quality were observed for ‘Hernandina’ clementine, which was chosen to make a new ready-to-eat product based on peeled citrus segments that were packaged in glass jars with a light syrup made of citrus juice and organic sugar cane. Different citrus juice mixtures were assayed and the most appreciated syrup, based on the sensory scores given by panellists, was that containing 50–50 (v/v) of ‘Fino’ lemon and ‘Hernandina’ clementine juices. In addition, different pasteurization treatments were assessed for their effects on conserving the safety, nutritional quality and sensory properties of the product during cold storage. The results show that pasteurization treatment at 50 °C for 45 min was sufficient to prevent microbial contamination with mesophilic and psychrophilic aerobic bacteria or yeast and mould and to maintain sensory properties until five weeks of storage at 4 °C. In addition, only a 10% reduction in vitamin C concentrations was observed in fresh-segments or syrup until the end of the storage period, showing that a high bioactive compound content and health benefits were conserved in the new ready-to-eat product after pasteurization and prolonged cold storage. Full article

Despite their importance in food processing, perfumery and cosmetics, the inheritance of sweet orange aromatic compounds, as well as their yield in the fruit peel, has been little analyzed. In the present study, the segregation of aromatic compounds was studied in an F1 population of 77 hybrids resulting from crosses between clementine and blood sweet orange. Fruit-peel essential oils (PEOs) extracted by hydrodistillation were analyzed by gas chromatography coupled with flame ionization detection. Genotyping by sequencing was performed on the parents and the hybrids. The resulting “clementine × sweet blood orange” genetic map consists of 710 SNP markers distributed in nine linkage groups (LGs), representing the nine citrus chromosomes, and spanning 1054 centimorgans. Twenty quantitative trait loci (QTLs) were identified, explaining between 20.5 and 55.0% of the variance of the major aromatic compounds and PEO yield. The QTLs for monoterpenes and aliphatic aldehydes predominantly colocalized on LGs 5 and 8, as did the two QTLs for PEO yield. The sesquiterpene QTLs were located on LGs 1, 3, 6 and 8. The detection of major QTLs associated with the synthesis of aliphatic aldehydes, known for their strong aromatic properties, open the way for marker-assisted selection. Full article

Conventional and innovative preservation treatments were compared to extend the shelf life of ready-to-eat Clementine (Citrus x Clementina) segments. The aim of this research was to find an environmentally friendly packaging typology for this fruit while preserving quality and meeting the needs of the consumer in terms of practicality of use and food safety. The experimental plan envisaged both the use of conventional storage techniques, such as modified atmosphere packaging (O₂ 5%, CO₂ 5%, and N₂ 90%), and the use of innovative storage techniques, such as an alginate-based (1.5%) edible coating. Quality changes were monitored by evaluating several indexes, such as color, texture, weight loss, respiration rate, pH, solid soluble content, bioactive compounds, antioxidant activity, organic acids, and microbiological contamination for 21 days at 4 °C. Moreover, a panel of judges assessed the sensory characteristics. Ready-to-eat Clementine segments, produced with edible coatings, possessed better sensory and textural properties and similar physic-chemical characteristics than those packaged in a modified atmosphere. The coating favored the creation of a controlled environment with low oxygen stress, which resulted in a reduction in enzymatic activity and oxidation for 20 days of storage at 4 °C. The results suggest that an edible coating could be a sustainable alternative to a modified atmosphere for the shelf life extension of ready-to-eat Clementine segments. Full article

WRKY proteins are an important group of transcription factors (TFs) gene family and were identified primarily in plants. WRKY TFs play vital roles in modulating gene expression when plants face detrimental effects due to the environment. In the current study, we focused on using the mandarin citrus (Citrus reticulata) genome to understand the impact of the WRKY gene family on the extraction of alleles mining in mandarins. The mining of the C. reticulata genome identified 46 CrWRKY genes that were classified into three main groups (G1, G2, and G3) further with five subclasses (IIa, IIb, IIc, Iid, and IIe) in the G2 group, and all were presented on 29 scaffolds representing numerous segmental duplications of 100% events established. Multiple sequence analysis predicted the presence of the “WRKYGQK” domain and metal-chelating zinc-finger motif C₂H₂ in 45 genes, while the “WRKYGQK” domain was replaced with “WRKYGKK” only in CrWRKY20. The comparative relationship of CrWRKY with other plant species using dual synteny analysis revealed that the divergence between C. reticulata and C. grandis occurred after the evolutionary divergence of C. clementine, C. sinensis, C. medica, and C. ichangensis. The possible functions of the CrWRKY genes in mitigating environmental effects were predicted using cis-regulatory elements analysis and in silico RNAseq analysis, for the development of plants. These results provide a robust platform and absence of knowledge for the functional identification from key genes of CrWRKY genes in the mandarin for the possible use to improve key desirable agronomic and consumer-driven fruit quality traits in mandarins and related species. Full article

Mandarins occupy the third group among citrus produced in Brazil. Primarily aimed at the fresh fruit market, commercial orchards have suffered significant production losses due to the high incidence of diseases, such as the alternaria brown spot (ABS) and huanglongbing (HLB). The fact that 80% of the orchards are composed of two varieties, Ponkan mandarin and Murcott tangor, which are highly susceptible to both diseases, demands intensive chemical control of the diseases in the field, which has resulted in a significant increase in production costs and a negative environmental impact. A total of one hundred and seventy-three mandarin accessions, including several species and hybrids belonging to the Collections of the Instituto Agronômico de Campinas (IAC), were evaluated in the field in an endemic location for the diseases. Evaluations of the incidence and severity of the diseases showed a range of genotypes tolerant to ABS that could replace the current commercial varieties, mainly within the clementine and willow leaf mandarin groups. Although, with differences in incidence and susceptibility to HLB, there are no tolerant varieties to this disease, which significantly impacts the loss of fruit quality. Full article

As a semi-arid/arid country located in the northwest of Africa, Morocco is facing serious water scarcity driven by the dual stresses of decreasing availability of water resources and increasing water demands. Virtual water trade could be an effective tool to alleviate water scarcity. The paper presents an analysis of the relationships between agrarian productions, foreign trade, and the water sector in Morocco by deriving a comprehensive estimate of virtual water export and import in Morocco’s foreign trade of 40 crop products during the period from 2000 to 2017. Our objectives include determining the intensity of water consumption of exported and imported crop products and quantifying the water consumed and saved, respectively, by locally producing and importing these products. To this end, FAO’s Penman-Monteith climate model was used to estimate crop water requirements based on data on meteorological factors. The results show that Morocco was a net virtual water importer during the study period. The deficit was 595.74 Gm³. The tendency of total virtual water export was on a rising trend, while the total virtual water import was on a downward trend. The main exported virtual water was from vegetables (68.87 Gm³, 72.47%) and the main imported virtual water was from cereals (679.68 Gm³, 98.4%). Regarding crop product’s water intensity, we found that the exported crop products were excessively concentrated on water-intensive products such as mandarins and clementines, figs, oranges, apricots, plums, citrus fruits, olives, tomatoes, asparagus, peas, and artichokes. On the other hand, the agricultural policy of 2009–2020 increased the production of water-intensive products. This finding seems to be going against the virtual water trade theory, which states that water-poor countries should import water-intensive products and produce local products with lower water requirements. Full article

Citriculture and the postharvest industry are in the quest for biostimulants that favour fruit quality and extend shelf-life. Recently, Si has emerged as a biostimulant and its impact on fruit quality and postharvest shelf-life needs to be elucidated. The experiment is conducted for two consecutive years (2019 and 2020) in a commercial citrus orchard. In the present study, a Si–Ca-based product (Gravital^® Force SC, AGROLOGY SA, Sindos, Greece) is foliar sprayed upon clementine mandarin (Citrus clementina Hort. Ex Tan cv. SRA 63) trees from August to November, while unsprayed trees are kept as controls. At commercial maturity, both sprayed and unsprayed fruits are harvested and stored for thirty (30) days at 5 °C with 90–95% relative humidity. Afterwards, they are kept at shelf temperature (20 °C) for six (6) days (shelf-life). At different intervals [at harvest, after cold storage (30 d at 5 °C), at the third day of shelf-life (30 d at 5 °C plus 3 d at 20 °C) and sixth day of shelf-life (30 d at 5 °C plus 6 d at 20 °C)], fruits are sampled and analysed for their qualitative characteristics. According to the results, the preharvest foliar application of the Si–Ca-based product delayed fruit maturation, increased peel firmness, total soluble content, total acidity, ascorbic acid, total phenols and antioxidant capacity, and reduced fruit decay during shelf storage. Results suggest that the preharvest foliar spray of Si–Ca products is able to maintain the postharvest quality of mid-ripening mandarin fruit. Full article