Fruit Color Changes Research Articles

Effectiveness of A Combination of Kitolod Leaves (Laurentia longiflora), Papaya Leaves (Carica papaya), and Lemongrass (Cymbopogon citratus) as Candidates for Biocides on Bactrocera Pests in Citrus sinensis Plants

Bactrocera is a pest that is detrimental to citrus farming. Bactrocera attacks cause developmental disorders in citrus fruit, including changes in fruit color (black spots appear from Bactrocera infection) and premature rot. Bactrocera also has a symbiotic relationship with Liberibacter asiaticus which causes Citrus Vein Phloem Degeneration (CVPD) disease which attacks phloem tissue in citrus plants. Bactrocera pest control was carried out by combining plants that have the potential to be used as biocides, namely kitolod, papaya, and lemongrass plants. This combination was used to switch the habits of fruit farmers who previously used synthetic pesticides to control pests. Natural biocides are expected to have the same effectiveness as synthetic pesticides, but leave no residue on cultivated plants. A combination biocide from the three plants was made using the maceration method to obtain an infusion from each plant. Before being tested on Citrus plantations, an assay was carried out using an olfactometer to determine the effectiveness of the biocides. The research revealed that the combination of these three plants has the potential to be used as a natural biocide without leaving residueand causing damage or other developmental disorders to citrus plants.

A Flowering Morphological Investigation, Fruit Fatty Acids, and Mineral Elements Dynamic Changes of Idesia polycarpa Maxim.

Idesia polycarpa Maxim is a high-value species of fruit oil with edible, abundant linoleic acid and polyphenols. Idesia polycarpa is described as a dioecious species, and the flowers are male; female and bisexual flowers are produced on separate plants. In order to explore the flower types of Idesia polycarpa, the morphology of its flowers and inflorescence were investigated in this study. The flower and inflorescence types, the diameter, and the flowering sequencing in male and female inflorescence were determined. We also detected the length, width, and fresh weight of leaves, shoots, and female inflorescence, as well as the length and fresh weight of the petiole during the development. Additionally, we compared the length, width, the length/width ratio, and the flowering density between 5- and 7-year-old female trees. The phenological period observation of Idesia polycarpa showed that the development process can be roughly divided into 12 stages, including bud burst, leaf expansion, inflorescence growth, initial flowering, full flowering, flower decline, initial fruiting, fruit enlargement, fruit color change, fruit ripening, post-ripening of fruit, and leaf fall periods. Furthermore, four elites' fruit determined the oil content and the composition of fatty acid content during the development. The dynamic of fatty acids contents, the palrnitic acid, palmitoleic acid, stearic acid, oleic acid, and linolenic acid contents were detected during the fruit development of four elites. Moreover, the mineral elements content of fruit of four elites during development were determined. The patterns of vegetative and reproductive growth in young dioecious trees of Idesia polycarpa provided the theoretical basis for artificial pruning and training.

Evaluation of Germicidal UV-C Light for Suppression of Grape Powdery Mildew and Botrytis Bunch Rot in Western Oregon.

Germicidal UV light (UV-C) has been shown to effectively suppress several plant pathogens as well as some arthropod pests. Recent reports describe the efficacy of nighttime applications of UV-C at doses from 100 to 200 J/m2 in vineyards to reduce grape powdery mildew (Erysiphe necator). Our in vitro studies confirmed the efficacy of UV-C to inhibit germination of E. necator and Botrytis cinerea conidia, demonstrated a range of tolerances to UV-C within a collection of E. necator isolates, and showed growth stage-specific effects of UV-C on B. cinerea. Nighttime use of UV-C was evaluated at 48 to 96 J/m2 in small plot trials (<1,000 vines) from 2020 to 2023. Once- or twice-weekly UV-C applications significantly reduced the incidence of foliar powdery mildew compared with non-UV-C-treated controls (P < 0.02). Suppression of powdery mildew on fruit was less consistent, where once or twice weekly UV-C exposure reduced powdery mildew disease severity in 2020 (P = 0.04), 2021 (P = 0.02), and 2023 (P = 0.003) but less so in 2022 (P = 0.07). Bunch rot severity was not significantly reduced with UV-C treatment in any year of the study. Application of UV-C until the onset of fruit color change (veraison) also had a minimal effect on the fruit-soluble solids, pH, anthocyanins, or phenolics in harvested fruit at any UV-C dose or frequency (P > 0.10). Suppression of powdery mildew by nighttime application of UV-C at lower doses in small plots suggests that such treatments merit further evaluation in larger-scale studies in Western Oregon.

Evaluation of genetic diversity among olive trees (Olea europaea L.) from Jordan.

This study aimed to identify and evaluate the genetic diversity of olive trees in Jordan, a country located in the eastern Mediterranean, where olive domestication originated. For this purpose, a total of 386 olive trees were analyzed, including 338 collected from two surveys (JOCC-1 and JOCC-2) across seven regions, and 48 selected accessions from the Olive Germplasm Bank of Jordan (JGBOC). These trees underwent comprehensive phenotypic and molecular characterization using different tools. Significant differences in morphological traits were detected among tested regions using the Chi-square test. Principal components analysis revealed that fruit color change and growth habit as the most discriminating traits, segregating the trees into two groups, with the first group including the Kanabisi cultivar and the second group including the Kfari Baladi cultivar. Utilizing Kompetitive Allele Specific PCR assay, two sets of informative SNPs were used for the genetic diversity analysis. Cladograms were constructed using the maximum likelihood method, revealing a consistent pattern where two clades containing identical genotypes were observed to cluster with the Kfari Baladi or Kanabisi. In addition, the SNP data was used to perform a comparative analysis with the Worldwide Olive Germplasm Bank of Córdoba, which revealed 73 unreported olive genotypes from Jordan. Genetic structure analyses using Discriminant Analysis of Principal Components (DAPC) identified four clusters with distinctive patterns of relatedness among 149 unique accessions, including 52 olive accessions from various Mediterranean countries (IOCC-3). ADMIXTURE analysis revealed four genetic clusters, consistent with the clustering observed in DAPC and cladogram analysis, indicating a high level of genetic admixture among Jordanian olive germplasm. In conclusion, the results show that olive trees in Jordan are highly diverse, providing valuable information for future conservation and management plans.

EXPLORING FRUGIVOROUS BIRDS’ ABILITY TO ADAPT TO ARTIFICIAL FRUIT COLOURS

Alteration of fruit traits for domestication purposes is expanding globally, yet its impact on the adaptability of frugivores, especially birds, remains unclear. Fruit traits have been known to evolve in response to interaction with frugivores. However, technology-driven alterations to fruit traits deviate from these natural processes. We investigated the influence of changing natural fruit colour on the behaviour of birds via frugivory rate on natural and alternative fruit colours. Modelling clay was used to create three different colours of fake fruits (natural, red, and blue) by mimicking the fleshy fruit of Ficus microcarpa L.f., 1782 and the field experiment was conducted in EcoHub, Universiti Sains Malaysia. We measured the spectral reflectance of each fruit colour and accessed their conspicuousness level through the avian eye model. We also analysed the peck marks on the fruits. A statistically significant result showed that birds’ preference was the highest for natural fruit colour. Our findings reflect the inadaptability of frugivorous birds to changes in natural fruit colour and we believe that exercising caution when pursuing agricultural advancements is essential to prevent unintended disruptions to ecosystems.

Interpretation and explanation of computer vision classification of carambola (Averrhoa carambola L.) according to maturity stage

The classification of carambola, also known as starfruit, according to quality parameters is usually conducted by trained human evaluators through visual inspections. This is a costly and subjective method that can generate high variability in results. As an alternative, computer vision systems (CVS) combined with deep learning (DCVS) techniques have been introduced in the industry as a powerful and an innovative tool for the rapid and non-invasive classification of fruits. However, validating the learning capability and trustworthiness of a DL model, aka black box, to obtain insights can be challenging. To reduce this gap, we propose an integrated eXplainable Artificial Intelligence (XAI) method for the classification of carambolas at different maturity stages. We compared two Residual Neural Networks (ResNet) and Visual Transformers (ViT) to identify the image regions that are enhanced by a Random Forest (RF) model, with the aim of providing more detailed information at the feature level for classifying the maturity stage. Changes in fruit colour and physicochemical data throughout the maturity stages were analysed, and the influence of these parameters on the maturity stages was evaluated using the Gradient-weighted Class Activation Mapping (Grad-CAM), the Attention Maps using RF importance. The proposed approach provides a visualization and description of the most important regions that led to the model decision, in wide visualization follows the models an importance features from RF. Our approach has promising potential for standardized and rapid carambolas classification, achieving 91 % accuracy with ResNet and 95 % with ViT, with potential application for other fruits.

Research on Multi-Step Fruit Color Prediction Model of Tomato in Solar Greenhouse Based on Time Series Data

Color change is the most obvious characteristic of the tomato ripening stage and an important indicator of the tomato ripening condition, which directly affects the commodity value of tomato. To visualize the color change of tomato fruit during the mature stage, this paper proposes a gated recurrent unit network with an encoder–decoder structure. This structure dynamically simulates the growth and development of tomatoes using time-dependent lines, incorporating real-time information such as tomato color and shape. Firstly, the .json file was converted into a mask.png file, the tomato mask was extracted, and the tomato was separated from the complex background environment, thus successfully constructing the tomato growth and development dataset. The experimental results showed that for the gated recurrent unit network with the encoder–decoder structure proposed, when the hidden layer number was 1 and hidden layer number was 512, a high consistency and similarity between the model predicted image sequence and the actual growth and development image sequence was realized, and the structural similarity index measure was 0.746. It was proved that when the average temperature was 24.93 °C, the average soil temperature was 24.06 °C, and the average light intensity was 11.26 Klux, the environment was the most suitable for tomato growth. The environmental data-driven tomato growth model was constructed to explore the growth status of tomato under different environmental conditions, and thus, to understand the growth status of tomato in time. This study provides a theoretical foundation for determining the optimal greenhouse environmental conditions to achieve tomato maturity and it offers recommendations for investigating the growth cycle of tomatoes, as well as technical assistance for standardized cultivation in solar greenhouses.

Phenotypic and Gene Expression Analysis of Fruit Development of ‘Rojo Brillante’ and ‘Fuyu’ Persimmon (Diospyros kaki L.) Cultivars in Two Different Locations

Fruit development and maturation rely on intrinsic genetic programs involving hormone biosynthesis and signalling and environmental cues, integrating phenological cycles and climatic issues encompassing abiotic stresses and climate change. In persimmon trees, environmental inputs strongly influence fitness and agricultural performance, and fruit yield can be severely compromised by them. We have grown two persimmon accessions (‘Rojo Brillante’ and ‘Fuyu’) under contrasting meteorological conditions of two locations in Spain and Japan. Fruit size, colour change, and firmness parameters were followed during fruit development from 30 days after fruit set until commercial ripening, and the expression of genes related to ethylene production and signalling, gibberellin response, carotenoid biosynthesis, cell wall dynamics, and oxidative stress were reported. Genes depending on intrinsic developmental programs (ethylene and ripening variables, mostly) showed common expression trends in both cultivars and locations, whereas gibberellin and abiotic stress-related genes mimicked reduced fruit growth and abiotic stress associated with higher summer temperatures (&gt;35 °C) and lower rainfall reported in the Spanish location. The expression pattern of these genes is consistent with a growth–defence trade-off that explains fruit differential growth through hormonal and stress tolerance mechanisms.

Integrative Analysis of Metabolome and Transcriptome of Carotenoid Biosynthesis Reveals the Mechanism of Fruit Color Change in Tomato (Solanum lycopersicum).

Tomato fruit ripening is accompanied by carotenoid accumulation and color changes. To elucidate the regulatory mechanisms underlying carotenoid synthesis during fruit ripening, a combined transcriptomic and metabolomic analysis was conducted on red-fruited tomato (WP190) and orange-fruited tomato (ZH108). A total of twenty-nine (29) different carotenoid compounds were identified in tomato fruits at six different stages. The abundance of the majority of the carotenoids was enhanced significantly with fruit ripening, with higher levels of lycopene; (E/Z)-lycopene; and α-, β- and γ-carotenoids detected in the fruits of WP190 at 50 and 60 days post anthesis (DPA). Transcriptome analysis revealed that the fruits of two varieties exhibited the highest number of differentially expressed genes (DEGs) at 50 DPA, and a module of co-expressed genes related to the fruit carotenoid content was established by WGCNA. qRT-PCR analysis validated the transcriptome result with a significantly elevated transcript level of lycopene biosynthesis genes (including SlPSY2, SlZCIS, SlPDS, SlZDS and SlCRTSO2) observed in WP190 at 50 DPA in comparison to ZH108. In addition, during the ripening process, the expression of ethylene biosynthesis (SlACSs and SlACOs) and signaling (SlEIN3 and SlERF1) genes was also increased, and these mechanisms may regulate carotenoid accumulation and fruit ripening in tomato. Differential expression of several key genes in the fruit of two tomato varieties at different stages regulates the accumulation of carotenoids and leads to differences in color between the two varieties of tomato. The results of this study provide a comprehensive understanding of carotenoid accumulation and ethylene biosynthesis and signal transduction pathway regulatory mechanisms during tomato fruit development.

Effect of UV-C Radiation Intensity on Post-harvest Quality of Two Eggplant Varieties (Solanum aetipicum anguivi L and Solanum macrocarpon L)

In Côte d’Ivoire, eggplant is one of the most cultivated and consumed vegetables. However, this vegetable is very perishable. This work was developed to evaluate the effect of different UV-C concentrations on the conservation of eggplants with a view to identifying which one would provide better conservation of eggplants grown in Côte d'Ivoire. In this study, two eggplant varieties Solanum aetiopicum anguivi L (Klongbo) and Solanum macrocarpon L (Gbokouman) were treated with three doses of UV-C (960 Kj m-2; 1920 Kj m-2 or 2880 Kj m-2) in order to determine the optimal dose: non-deleterious while preserving or enhancing the qualitative attributes of the vegetable. The proximate composition and the infection rate were determined according to standard and referenced methods. Treatment at 960 Kj m-2 had no significant effect on fruit quality attributes compared to untreated fruit, while treatment at 2880 Kj m-2 accelerated fruit color changes and loss fruit mass. The treatment at 1920 Kj m-2 allowed the fruits to better preserve their quality over time. During this treatment, the infection rate was reduced by 45 % for the “Gbokouman” variety and 40 % for the “Klongbo” variety. With this same dose of UVC, mass loss was reduced by 10.74% for the “Klongbo” variety and 33.48 % for the “Gbokouman” variety. An increase in the content of phenolic compounds as well as that of antioxidant activity was also observed. The dose of 1920 Kj m-2 is therefore the optimal dose which would allow the “Gbokouman” and “Klongbo” eggplant varieties to be preserved for a long period of marketing and conservation.

Color and Firmness Quality Changes of Java Apple During Postharvest Transportation and Storage

Transportation vibration adversely affects fresh produce during transportation. In addition, storage temperature affects the quality of fresh commodities. The physical changes in Java apples during transportation and storage were evaluated in this study. Java apples were transported from local farms to wholesale markets (180 km). Java apples were stored at room temperature (28°C) for six days. Physical qualities such as weight loss and firmness of the Java apple samples were evaluated. The RGB image acquisition system was used to assess changes in the color of the Java apple. The vibration showed that more than 70% of the acceleration occurred between 220-290 cm/s2 in the vertical and horizontal directions during transportation. Analysis showed that physical qualities, such as weight loss and firmness, were strongly affected by the packaging used, vibration during transportation, and storage temperature. The weight loss and reduction in firmness was highest in Java apples transported using wholesaler packaging (packaging A). The lightness, yellowness, and hue values decreased significantly because transportation vibration was relatively high, and the Java apples were stored at room temperature. Redness, total color difference, and color index increased significantly in Java apples that were transported using package A and stored at room temperature. The results showed that the use of transportation packaging affected changes in the physical quality of Java apples. Packaging A generally increase in weight loss, hardness, and changes in fruit color than other packaging types.

Apple (Malus × domestica Borkh.) production and quality in response to anti-hail nets.

Anti-hail nets are the best way to mitigate the effects of hailstorms in the orchards. Apple trees covered with nets may exhibit a variety of vegetative and reproductive responses, inclusive of changes in tree vigour, cropping, sugar contents, and fruit colour. The present study was conducted to assess the effect of timing of installation and colour of anti-hail net on cropping and fruit quality in high-density apple orchard for two consecutive seasons (2021 and 2022). White and blue colour nets of size (9m × 30m) 80 GSM (square mesh with non-sliding threaded, leno weave, and < 30% shading factor) were installed at three different time intervals (15days before estimated full bloom, at full bloom, and 15days after full bloom) on apple cultivar 'Jeromine'. The installation at different time and colour of anti-hail nets significantly exhibit variability in cropping, fruit quality, and bio-chemical metrics. The significant highest cropping (fruit yield, productivity, and yield efficiency) and fruit biochemical parameters (total soluble solids) were recorded in T3C2 (15days after full bloom + white colour anti-hail net) followed by T2C2 (installed at full bloom + white colour anti-hail net). Hence, white colour anti-hail nets installed 15days after full bloom increased fruit production and improved quality in comparison to blue colour anti-hail net in apple under high-density plantations.

Accumulation Patterns of Metabolites Responsible for the Functional Quality of Virgin Olive Oil during Olive Fruit Ontogeny.

The health-promoting antioxidant properties of virgin olive oil (VOO) are today considered priority targets in the new olive breeding programs. Given that these properties depend mainly on its phenolic fraction, whose origin lies in the phenolic compounds present in olive fruit, the objective of this study was to provide further insight into the accumulation dynamics of the main antioxidant compounds, including both polar phenolics and lipophilic tocopherols, during the ontogeny of the olive fruit. Data obtained show that, albeit with significant differences, all the studied genotypes share just after fruit set an intense increase in the synthesis of tyrosol and hydroxytyrosol derivatives, by far the main phenolic compounds of the olive fruit, and a subsequent steady decrease along fruit development and ripening. The accumulation dynamics of flavonoids and tocopherols were different from those of tyrosol and hydroxytyrosol derivatives, presenting a peak of synthesis just before the onset of fruit ripening, and then in general, their content decreases throughout the ripening phase. In the case of flavonoids, all genotypes also share a strong increase in the accumulation of anthocyanins in the final stages of fruit ripening, coinciding with the change in fruit color. Furthermore, the results during the fruit ripening process evidenced that the content of tyrosol and hydroxytyrosol derivatives and tocopherols in the fruit largely determines the content of these groups of compounds in the oil. The information acquired could be useful for the selection of the most suitable moment in the ontogeny of the olive fruit for the search for key genes in the biosynthesis of phenolic compounds.

Botanical‐based simulation of color change in fruit ripening: Taking tomato as an example

AbstractThe color change of plant fruit in ripening is a typical time‐varying phenomenon involving various factors. Due to its complexity and biodiversity, it is challenging to model this phenomenon. To address this issue, we take the tomato as an example and propose a botanical‐based framework considering variety, environment, phytohormone, and genes to simulate fruit color change during the ripening process. Specifically, we propose a first‐order kinetic model that integrates varietal, environmental, and phytohormonal factors to represent the variation of pigment concentrations in the pericarp. Moreover, we introduce a logistic model to describe the change in pigment concentration in the epidermis. Based on the gene expression pathway of tomato color in botany, we propose a genotype‐to‐phenotype simulation method to represent its biodiversity. An improved method is proposed to convert pigment concentrations into color accurately. Furthermore, we propose a gradient descent‐based method to assist the user in quickly setting pigment concentration parameters. Experiments verified that the proposed framework can simulate a wide range of tomato colors. Both qualitative and quantitative experiments validated the proposed method. Furthermore, our framework can be applied to more fruits.

Transcriptome Insights into Candidate Genes of the SWEET Family and Carotenoid Biosynthesis during Fruit Growth and Development in Prunus salicina 'Huangguan'.

The Chinese plum (Prunus salicina L.) is a fruit tree belonging to the Rosaceae family, native to south-eastern China and widely cultivated throughout the world. Fruit sugar metabolism and color change is an important physiological behavior that directly determines flavor and aroma. Our study analyzed six stages of fruit growth and development using RNA-seq, yielding a total of 14,973 DEGs, and further evaluation of key DEGs revealed a focus on sugar metabolism, flavonoid biosynthesis, carotenoid biosynthesis, and photosynthesis. Using GO and KEGG to enrich differential genes in the pathway, we selected 107 differential genes and obtained 49 significant differential genes related to glucose metabolism. The results of the correlation analyses indicated that two genes of the SWEET family, evm.TU.Chr1.3663 (PsSWEET9) and evm.TU.Chr4.676 (PsSWEET2), could be closely related to the composition of soluble sugars, which was also confirmed in the ethylene treatment experiments. In addition, analysis of the TOP 20 pathways between different growth stages and the green stage, as well as transient overexpression in chili, suggested that capsanthin/capsorubin synthase (PsCCS) of the carotenoid biosynthetic pathway contributed to the color change of plum fruit. These findings provide an insight into the molecular mechanisms involved in the ripening and color change of plum fruit.

The miR156/SPL12 module orchestrates fruit colour change through directly regulating ethylene production pathway in blueberry.

Colour change is an important event during fruit ripening in blueberry. It is well known that miR156/SPLs act as regulatory modules mediating anthocyanin biosynthesis and ethylene plays critical roles during colour change, but the intrinsic connections between the two pathways remain poorly understood. Previously, we demonstrated that blueberry VcMIR156a/VcSPL12 affects the accumulation of anthocyanins and chlorophylls in tomato and Arabidopsis. In this study, we first showed that VcMIR156a overexpression in blueberry led to enhanced anthocyanin biosynthesis, decreased chlorophyll accumulation, and, intriguingly, concomitant elevation in the expression of ethylene biosynthesis genes and the level of the ethylene precursor ACC. Conversely, VcSPL12 enhanced chlorophyll accumulation and suppressed anthocyanin biosynthesis and ACC synthesis in fruits. Moreover, the treatment with ethylene substitutes and inhibitors attenuated the effects of VcMIR156a and VcSPL12 on pigment accumulation. Protein-DNA interaction assays indicated that VcSPL12 could specifically bind to the promoters and inhibit the activities of the ethylene biosynthetic genes VcACS1 and VcACO6. Collectively, our results show that VcMIR156a/VcSPL12 alters ethylene production through targeting VcACS1 and VcACO6, therefore governing fruit colour change. Additionally, VcSPL12 may directly interact with the promoter region of the chlorophyll biosynthetic gene VcDVR, thereby activating its expression. These findings established an intrinsic connection between the miR156/SPL regulatory module and ethylene pathway.

Comparative Physiological and Transcriptome Analyses Reveal Mechanisms of Salicylic-Acid-Reduced Postharvest Ripening in 'Hosui' Pears (Pyrus pyrifolia Nakai).

Postharvest ripening of sand pear fruit leads to quality deterioration, including changes in texture, flavor, and fruit color. Salicylic acid (SA), an important defense-related hormone, delays fruit ripening and maintains fruit quality, but the underling mechanism remains unclear. Herein, we evaluated the efficacy of SA in delaying the ripening process of Pyrus pyrifolia cv. 'Hosui' pear fruit, as evidenced by the reduction in fruit weight loss, inhibition of firmness loss, cell wall degradation and soluble sugars, and retention of total phenols. Based on comparative transcriptomic data, a total of 3837 and 1387 differentially expressed genes (DEGs) were identified during room-temperature storage of control fruit and between SA-treated and control fruit, respectively. Further KEGG analysis revealed that the DEGs were mainly implicated in plant hormone signal transduction, starch and sugar metabolism, and cell wall modification. Moreover, exogenous SA treatment also altered the expression of many transcription factor (TF) families, including those in the ethylene-responsive factor (ERF), NAM, ATAF, CUC (NAC), basic helix-loop-helix (bHLH), basic leucine zipper (bZIP), and v-myb avian myeloblastosis viral oncogene homolog (MYB) families. Together, the results offer important insights into the role of SA-responsive genes in controlling fruit ripening in sand pears.

Pre-Harvest Salicylic Acid Application Affects Fruit Quality and Yield under Deficit Irrigation in Aristotelia chilensis (Mol.) Plants.

Salicylic acid (SA) application is a promising agronomic tool. However, studies under field conditions are required, to confirm the potential benefits of SA. Thus, SA application was evaluated under field conditions for its effect on abscisic acid levels, antioxidant related-parameters, fruit quality, and yield in Aristotelia chilensis subjected to different levels of irrigation. During two growing seasons, three-year-old plants under field conditions were subjected to full irrigation (FI: 100% of reference evapotranspiration (ETo), and deficit irrigation (DI: 60% ETo). During each growth season, a single application of 0.5 mM SA was performed at fruit color change by spraying fruits and leaves of both irrigation treatments. The results showed that DI plants experienced moderate water stress (-1.3 MPa), which increased ABA levels and oxidative stress in the leaves. The SA application facilitated the recovery of all physiological parameters under the DI condition, increasing fruit fresh weight by 44%, with a 27% increase in fruit dry weight, a 1 mm increase in equatorial diameter, a 27% improvement in yield per plant and a 27% increase in total yield, with lesser oxidative stress and tissue ABA levels in leaves. Also, SA application significantly increased (by about 10%) the values of fruit trait variables such as soluble solids, total phenols, and antioxidant activity, with the exceptions of titratable acidity and total anthocyanins, which did not vary. The results demonstrated that SA application might be used as an agronomic strategy to improve fruit yield and quality, representing a saving of 40% regarding water use.

Multi-omics analysis reveals the mechanism of calcium-reduced quality deterioration in mechanically injured green pepper fruit

Green pepper is regarded as one of the globally essential commercial crops with bright color and rich nutrition. However, green pepper is susceptible to mechanical injuries as a result of vibration, compression and impact events during postharvest handling and transportation. These injuries can induce physiological and biochemical abnormalities in fruit, thus accelerating fruit senescence and leading to economic losses. Calcium chloride (CaCl2) treatment is a safe, effective and economical method to maintain fruit quality during postharvest storage. Here, the impact of calcium treatment on the fruit quality of mechanically injured green pepper was investigated. The results indicated that calcium treatment maintained the sensory quality and hardness of green pepper fruit, inhibited redness development and elevation in the level of malondialdehyde (MDA). The combination of transcriptomics, metabolomics and assay for transposase accessible chromatin with high-throughput sequencing (ATAC-seq) revealed treatment effects of the expression of key genes related to fruit color change, fruit softening, active oxygen metabolism and hormone response, as well as changes of metabolites concentrations, and chromatin accessibility changes. A construction of regulatory network model of calcium treatment on post-harvest mechanical injury of green pepper fruit was developed based on these effects. Overall, the study provides valuable insights into the impact of mechanical injury on fruit after harvest and its amelioration by calcium.

Advantages of hydroxyl radical water treatment for the fruits and vegetables preservation

In this study, the effects of hydroxyl radical water (HRW) treatment on the functional components, volatile compounds, and preservation properties of cherry tomatoes, grapes, coriander, and celery were investigated. The results demonstrated that HRW treatment could be significantly effective in delaying the color change and decay of fruits and vegetables. The loss of total sugars in the HRW-treated samples was relatively low, ranging from 0.02% to 0.84%. However, other functional components will be more severely affected. Specifically, celery exhibited a 17.95% decrease in total phenols and a 13.01% decrease in ascorbic acid, which may be caused by excessive surface area, indicating that the applicability of HRW to celery remains to be studied. The loss of functional components of both fruits could be controlled under 4%. Throughout the treatment, the phenolic profiles and volatile compounds remained stable. Notably, an increase in partial ester compounds, such as ethyl caproate, was observed in HRW-treated cherry tomatoes, which might improve the sensory function. Moreover, the reduction of some compounds obtained from the decomposition of fatty acid hydroperoxides may enhance the fresh odor of fruits and vegetables. Consequently, HRW treatment emerges as a safe and environmentally friendly technology for postharvest processing of fruits and vegetables.