Postharvest Diseases Research Articles

Identification and Application of Streptomyces rapamycinicus CQUSh011 against Potato Late Blight.

Using chemical fungicides is the main strategy for controlling potato late blight (PLB), a devastating pre- and postharvest disease caused by Phytophthora infestans, resulting in environmental pollution and health risks. It is of great importance to develop a biofungicide from microorganisms. Through isolating potato rhizosphere microorganisms, CQUSh011 was found to have antioomycete activity with strong inhibition on vegetative growth and virulence of P. infestans. Morphological and molecular identification indicated that CQUSh011 belongs to Streptomyces rapamycinicus. Based on genome, metabolome, and HPLC quantification, rapamycin and salicylic acid were found to be the two active metabolites against P. infestans. Continuous field trials showed that CQUSh011 has sustainable control efficiency against PLB, and the efficiency was better when combined with Infinito, along with an increased endophytic microbial community and biodiversity in potato roots. The results demonstrated the potential of CQUSh011 as a biofungicide against PLB and provided an alternative strategy for reducing the application of chemical fungicides.

Antifungal Effects and Postharvest Diseases Control Potential of E, E-2, 4-Nonadienal against Rhizopus stolonifer.

Pathogenic microorganisms are a significant cause of food spoilage, adversely affecting both product quality and human health. This study evaluated the antifungal activities of 34 aldehydes against foodborne and plant pathogenic fungi, identifying 8 promising lead compounds. Among them, E, E-2, 4-nonadienal exhibited optimal effects against Rhizopus stolonifer with an EC50 of 11.29 μg/mL. In vitro assays demonstrated that E, E-2, 4-nonadienal significantly impact R. stolonifer through both direct contact and fumigation. The preliminary mode of action (MOA) studies indicated that it effectively inhibited spore germination, disrupted ergosterol biosynthesis, and induced oxidative stress, affecting the permeability of the fungal cell membrane and altering mycelial morphology. Additionally, E, E-2, 4-nonadienal significantly reduced soft rot in spore-infected stored cherry tomatoes and showed low toxicity. Thus, aldehydes, exemplified by E, E-2, 4-nonadienal, are potential food and agricultural preservatives, offering efficiency, safety, and cost-effectiveness.

A deep learning approach to detect diseases in pomegranate fruits via hybrid optimal attention capsule network

In 2022, the production rate of pomegranate is estimated at approximately 4.8 million metric tons. Unfortunately, these fruits are susceptible to many different kinds of diseases caused by bacterial, viral, and fungal infections. Such diseases can have a major negative impact on fruit quality, production, and the profitability of pomegranate cultivation. Nowadays, several machine learning and deep learning methods are used to identify pomegranate fruit diseases automatically and effectively. In post-harvest pomegranate fruit disease detection, deep learning has great potential to extract complex patterns and features from large datasets. This can improve disease identification accuracy, enabling more efficient disease control, lower crop losses, and better resource management. The proposed work introduces an intelligent deep learning-based approach for accurately detecting pomegranate diseases, begins with Improved Guided Image Filtering (Improved GIF) and resizing to pre-process fruit images, followed by feature extraction (shape, color, texture) using GLCM and GLRLM to streamline classification. Extracted features are then fed into a novel Hybrid Optimal Attention Capsule Network (Hybrid OACapsNet), which classifies the images as normal or diseased, conditions such as bacterial blight, heart rot, and scab. Our analysis indicates that the proposed classifier has a classification accuracy of 99.19 %, precision of 98.45 %, recall of 98.41 %, F1-score of 98.43 %, and specificity of 99.45 % compared to other techniques. So this approach offers a, which is a feasible solution for automated detection of diseases in fruits, thereby benefiting farmers and supporting their farming operations.

Antifungal Activity of Citrus Essential Oil in Controlling Sour Rot in Tahiti Acid Lime Fruits.

Sour rot, caused by Geotrichum citri-aurantii, is a significant post-harvest disease in citrus, resulting in economic losses due to the lack of effective fungicides. This study investigates the antifungal activity of citrus essential oils in controlling sour rot in Tahiti acid lime fruits. Essential oils were extracted via hydrodistillation with chemical composition analyzed by CG-MS and tested in vitro and in vivo. In vitro assays evaluated mycelial growth inhibition at 2 to 32 µL mL-1 concentrations. In vivo trials involved preventive and curative treatments on artificially inoculated fruits stored at 25 °C ± 2, and the results showed that Pera IAC sweet orange oil, at 32 µL mL-1, reduced disease severity by 96% in curative treatments. In contrast, Late IAC 585 willowleaf mandarin oil demonstrated moderate inhibition (44%) at the highest concentration in vitro. The oils did not affect key fruit quality parameters such as juice yield and total soluble solids. These findings suggest that citrus essential oils could be natural alternatives to synthetic fungicides for post-harvest sour rot management, combining effectiveness with maintaining fruit quality.

Control of Alternaria alternata by sodium alginate and natamycin treatments of sweet cherry

Natamycin, a natural antifungal produced through fermentation by streptomyces, can promote postharvest disease resistance in fruit. Sodium alginate is often used as film-forming matrices for fabricating antibacterial composite coatings for the preservation of fruit and vegetables. This study investigated the inhibitory effects of sodium alginate, natamycin, or combined treatment on Alternaria alternata infection in 'Jimei' sweet cherry postharvest using various biochemical and enzyme assays along with spectrophotometry. The results showed that the combined treatment of natamycin and sodium alginate inhibited the development of A. alternata. After 7 d of treatment, the lesion diameter of the combined treatment fruit was 64.4 % lower than that of the control. Further studies showed that the combined treatment significantly reduced the contents of hydrogen peroxide (H2O2), superoxide anion (O2-·) and malondialdehyde (MDA) in the fruit defense system, and enhanced the activities of antioxidant enzymes, chitinase (CHI) and β-1,3-glucanase (GLU). The results showed that the combined treatment of postharvest natamycin and sodium alginate effectively enhanced disease resistance by inhibiting the production of reactive oxygen species (ROS) and activating defense-related proteins in cherry fruits.

In Vitro Assessment of Penicillium expansum Sensitivity to Difenoconazole

Penicillium expansum causes blue mold, a major post-harvest disease affecting apples. This disease is commonly managed using fungicides, including Difenoconazole (Dif), a demethylation inhibitor (DMI) approved for its control. This investigation aims to evaluate the baseline sensitivity of 100 P. expansum isolates to Difenoconazole. The isolates were collected from symptomatic apples in 34 storage warehouses across the Fes-Meknes and Draa-Tafilalet regions over three years (2020, 2021, and 2022). The study revealed an increase in the percentage of inhibition of mycelial growth and spore germination of P. expansum proportional to the increasing concentration of the fungicide. Moreover, the results indicate that 46 isolates were able to develop even at a concentration of 5 µg/mL of Dif (the suggested discriminatory dose), indicating reduced sensitivity to this fungicide. The analysis of the values of the effective concentration to inhibit 50% (EC50) of mycelial growth of P. expansum ranging from 0.027 to 1.673 µg/mL (mean: 0.263 µg/mL, variation factor: 62.507) and for spore germination from 0.0002 to 0.787 µg/mL (mean: 0.048 µg/mL, variation factor: 4113.835). The wide variation in EC50 values indicates significant variability in the isolates’ responses to Dif, likely due to diverse sampling in space and time. Our results showed that some P. expansum isolates could grow even at high concentrations of Dif, indicating limited efficacy of this treatment. The EC50 of five isolates exceeded 0.92 µg/mL, suggesting potential resistance. This study indicates reduced sensitivity and possible emergence of resistant strains. Notably, it is the first evaluation of P. expansum sensitivity to Dif in Morocco.

Antimicrobial activity of blue mold (Penicillium italicum) Filtrates against some species of pathogenic bacteria

Background: Penicillium saprophytic species, which primarily consume organic biodegradable materials, is a common example of a fungal species. The preparation filtrates of Penicillium italicum, a saprophyte on citrus fruits frequently linked to post-harvest diseases in this crop, were included in the current investigation. Objective: This investigation aimed determine the most efficient culture medium for the production of antibacterial secondary metabolites. Patients and Methods: included identifying the growth medium for P. italicum and produce its metabolites through the use of gas chromatography-mass spectrometry (GC MS) for both solid-state fermentation filtrate (SSFF) and liquid fermentation filtrate (LFF). Additionally, the antimicrobial activity of the mold filtrate against certain pathogenic bacteria was assessed using the agar well diffusion method. Results: indicated that the biomass used for mold growth was heavier in SSFF than LFF, and according to the findings, the selective active isolate's crude filtrate from two duplicates of the P. italicum Yeast Extract Sucrose YES culture medium was 0.063 mg, while the crude extract from rotten orange (as a solid medium) containing P. italicum was 0.11 mg. Tetracosane and other substances with a track record of therapeutic activity were found in the two mold extracts, according to GC MS data. Overall, both SSFF and LFF demonstrated antibacterial activity against Klebsiella pneumonia, Escherichia coli, Acinetobacter baumannii, Pseudomonas aeruginosa and Staphylococcus aureus, with the inhibition zones± standard deviation (IZ± SD) being 24.7± 0.57, 18.2± 0.28, 26.3± 0.59, 21.6± 0.51, and 32.8± 0.21 (for SSFF) mm and 0.0, 12.3±0.57, 28.16±0.20, 19.3±1.15, and 28±0.2 (for LFF) mm, respectively. Conclusion: the filtrate of P. italicum from a natural medium (rotted orange) as a solid state fermentation was more weighted and gave many effective metabolites compared to what was produced by liquid fermentation on a synthetic medium, and both liquid and solid fermentation filtrates demonstrated efficacy against harmful bacteria.

Citrus bliss: potassium, sodium, and calcium silicates secrets for post-harvest diseases of fruit defense

Biotic stress significantly challenges the global citrus industry. Major post-harvest issues include diseases caused by Penicillium digitatum, Penicillium italicum, Geotrichum citri-aurantii, Alternaria alternata, and Phytophthora citrophthora. The negative impact of chemical fungicides on the environment and health necessitates eco-friendly alternatives. This study examines the effectiveness of sodium, potassium, and calcium silicates against common citrus diseases. In vitro tests evaluated mycelial growth inhibition using silicate concentrations from 0 to 10,000 ppm after 7 days at 25°C. Sodium silicate showed the highest efficacy, completely inhibiting P. digitatum and P. italicum at 2000 ppm. Potassium and calcium silicates achieved 100% inhibition against Penicillium spp. at a concentration of 1%. In vivo tests on Sidi Aissa clementines assessed the preventive and curative effects of 1, 2, and 6% silicate salt solutions. Sodium silicate prevented 41% of brown rot, 72% of sour rot, and 100% of green mold at 6%. Calcium silicate at 6% significantly reduced blue mold and black rot by 32% and 74%, respectively. Sodium silicate was most effective in curative treatments, suggesting its potential as a pre- or post-harvest spray to control P. digitatum, P. italicum, and G. citri-aurantii.

Induced Resistance in Fruit and Vegetable Enhancing Host Defence to Curve Post-harvest Diseases

Induced resistance (IR) is an emerging, environmentally friendly strategy to manage post-harvest diseases in fruits and vegetables by enhancing the plant’s innate immune system. This approach leverages the plant's natural defense mechanisms, including the activation of defense-related enzymes like chitinases, glucanases, and peroxidases, accumulation of secondary metabolites such as phytoalexins and phenolics, and the strengthening of cell walls to prevent pathogen invasion. Additionally, the production of reactive oxygen species (ROS) plays a crucial role in both signaling and direct pathogen inhibition. Despite its potential, the effectiveness of IR varies across different crops and pathogens, and its success is heavily influenced by environmental factors, such as humidity, temperature, and light. There are also concerns regarding possible trade-offs, such as reduced yield or changes in fruit quality due to the diversion of energy towards defense responses. However, the integration of IR with other disease management strategies, including the use of biological control agents and conventional fungicides, has shown promising results in reducing post-harvest losses. Case studies in fruits like apples, tomatoes, and citrus, as well as vegetables like potatoes and peppers, demonstrate the practical applications of IR in commercial agriculture. Advances in genetic engineering are opening new pathways for enhancing IR by manipulating key genes involved in defense pathways, while new formulations and precision agriculture technologies offer greater control and efficiency in IR applications. These innovations, along with optimized post-harvest handling and storage practices, hold the potential to make IR a more reliable and sustainable solution for managing post-harvest diseases. However, ongoing research is necessary to address the variability in effectiveness and to explore long-term sustainability, especially as pathogens evolve and environmental conditions change. Induced resistance, when integrated with a comprehensive disease management approach, offers a significant step forward in reducing post-harvest losses and improving food security globally.

A Diagnostic Guide for Fusarium Fruit Rot of Pumpkin and Winter Squash

Fusarium fruit rot caused by Fusarium solani f. sp. cucurbitae is an important postharvest disease impacting the global production and storage of pumpkins and winter squash ( Cucurbita spp.). The pathogen infects fruit through wounds, causing water-soaked lesions that may become sunken, coalesce, and be covered by fine mycelial growth. F. solani is soilborne and can survive long term in soil and plant debris. Storage rots impact several Cucurbita spp. grown for long-term storage. F. solani f. sp. cucurbitae has two races and is the most commonly found Fusarium species infecting cucurbits. Identification includes morphologic and PCR-based methods. This guide outlines taxonomy, symptoms, isolation, and epidemiology and provides methods to identify the pathogen.

Exogenous Nitric Oxide Induces Pathogenicity of Alternaria alternata on Huangguan Pear Fruit by Regulating Reactive Oxygen Species Metabolism and Cell Wall Modification.

Black spot caused by Alternaria alternata is one of the most common postharvest diseases in fruit and vegetables. A comprehensive investigation into its pathogenicity mechanism is imperative in order to propose a targeted and effective control strategy. The effect of nitric oxide (NO) on the pathogenicity of A. alternata and its underlying mechanism was studied. The results showed that treatment with 0.5 mM L-1 of sodium nitroprusside (SNP) (NO donor) increased the lesion diameter of A. alternata in vivo and in vitro, which was 22.8% and 13.2% higher than that of the control, respectively. Exogenous NO treatment also induced endogenous NO accumulation by activating nitric oxide synthase (NOS). In addition, NO triggered an increase in reactive oxygen species (ROS) levels. NO enhanced activities and gene expression levels of NADPH oxidase (NOX), superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), glutathione peroxidase (GPX), and glutathione reductase (GR). Moreover, NO stimulated cell wall degrading enzymes by activating the corresponding gene expression in vivo and in vitro. These results suggested that exogenous NO promoted the pathogenicity of A. alternata by inducing ROS accumulation and activating antioxidants and cell wall degrading enzymes. The present results could establish a theoretical foundation for the targeted control of the black spot disease in pear fruit.

Dimethyl trisulfide reduces postharvest anthracnose and enhances mango quality, and a potential molecular mechanism against Colletotrichum gloeosporioides

Mango anthracnose, mainly caused by Colletotrichum gloeosporioides, is the major destructive postharvest disease of mango during storage and transport. Dimethyl trisulfide (DMTS), an organic volatile found in some microorganisms or plants, inhibited growth of C. gloeosporioides in vitro, but its effects on mango anthracnose and its molecular mechanisms of action have not been well characterized. In this study, the EC50 of DMTS against Colletotrichum spp. from mango mainly ranged from 2.3 to 20.0 μL/L. In vivo, the fumigation rates of 20 μL/L of DMTS for 24 h, or 80 μL/L for 3 h or 6 h could effectively reduce severity of anthracnose (natural inoculum) on postharvest mangoes with inhibitory effects of 61.7 %, 65.7 %, and 69.4 %, respectively, as observed 10 days after treatment. Furthermore, there was no detectable DMTS residue in mango skin or flesh, and an overall improvement in the quality of the fruit with higher soluble solids, total sugars, vitamin c, and β-carotene, and lower titratable acidity than the non-treated control. In addition, DMTS could significantly reduce ergosterol content in mycelia of C. gloeosporioides, and gene expression analysis showed DMTS significantly suppressed expression of ergosterol biosynthesis-related genes Cgerg6 and Cgerg11 after mycelia were exposed to DMTS. Knock-out mutants for each of these two genes showed reduced sensitivity to DMTS. After gene complementation in situ, the sensitivity of complementary transformants to DMTS was restored to that of the parental strain. Therefore, we concluded that the genes Cgerg6 and Cgerg11 are involved in an interaction with the antifungal activity of DMTS. This is the first study to demonstrate a control effect of DMTS on mango postharvest anthracnose resulting in reduced disease severity and enhanced fruit quality. Transformant studies also revealed some potential molecular mechanisms of the antifungal activity of DMTS that may lead to improved management of mango postharvest anthracnose.

Biocontrol potential of Burkholderia gladioli STPT16 on postharvest decay of litchi fruit caused by Peronophythora litchii and Colletotrichum fructicola

Litchi downy blight (LDB) caused by Peronophythora litchii and anthracnose (AD) caused by Colletotrichum species are major pre- and postharvest disease of litchi fruit. Biocontrol agents such as Burkholderia has been applied for controlling postharvest fruit decay. In this work, an endophytic strain SZPT16 isolated from health litchi branch was identified as Burkholderia gladioli and exhibited strong antagonistic activity against mycelial growth and conidia/sporangia germination of two postharvest pathogens. Dual incubation of pathogen and biocontrol agents caused alterations in hyphal and conidial/sporangial structures and severe cell morphology changes such as mycelia deformation, cell wall collapse and cellular disorganization. Cell-free culture filtrates (CF, diluted at 25-fold) of B. gladioli SZPT16 showed an efficient inhibition on postharvest litchi decay by preharvest application (74.77 % protection) and postharvest application (64.68 % and 71.14 % protection for LDB and AD, respectively). Furthermore, UPLC-MS/MS metabolomic analysis identified 41 up-regulated differential metabolites, which mainly included nucleosides, nucleotides, and analogues, organic acids and derivatives, organic oxygen compounds, and organoheterocyclic compounds. This study firstly reported the efficacy of CF of B. gladioli SZPT16 in protecting postharvest litchi fruit against natural and inoculated pathogen infections. The overall results provide a promising alternative to chemical fungicides to control litchi postharvest decay.

New Trichoderma Strains Suppress Blue Mold in Oranges by Damaging the Cell Membrane of Penicillium italicum and Enhancing Both Enzymatic and Non-Enzymatic Defense Mechanisms in Orange Fruits

Blue mold disease, caused by Penicillium italicum (P. italicum), presents a significant challenge to orange fruits (Citrus sinensis L.) and other citrus crops globally. Biological control, particularly Trichoderma species, offers a promising alternative to synthetic fungicides. Therefore, this study aimed to isolate, identify, and evaluate the antagonistic activities of two Trichoderma isolates against P. italicum. These isolates were molecularly identified and assigned accession numbers PP002254 and PP002272, respectively. Both isolates demonstrated significant antifungal activity in dual culture assays. Moreover, the culture filtrates (CFs) of Trichoderma longibrachiatum PP002254 and Trichoderma harzianum PP002272 suppressed the mycelial growth of P. italicum by 77.22% and 71.66%, respectively. Additionally, CFs reduced the severity of blue mold on orange fruits by 26.85% and 53.81%, compared to 100% in the control group. Scanning electron microscopy revealed that treated P. italicum hyphae were shrunken and disfigured. Enzyme activities (catalase, peroxidase, polyphenol oxidase, and phenylalanine ammonia-lyase) in treated oranges increased, along with total soluble phenolics and flavonoids. Conversely, malondialdehyde (MDA) levels decreased in treated fruits. These findings suggest that T. longibrachiatum PP002254 and T. harzianum PP002272 could be effective biocontrol agents for managing blue mold and other citrus postharvest diseases.

Exploration of antimicrobial activities and mechanisms of biocontrol agent Serratia nematodiphila BC-SKRU-1 against Penicillium digitatum in tangerine fruit

The isolate BC-SKRU-1, identified as Serratia nematodiphila from fungal culture contamination, was investigated for its biocontrol potential against Penicillium digitatum in vitro and on tangerine fruit, with a focus on its mechanisms of action. In vitro tests on PDA plates revealed BC-SKRU-1's broad-spectrum antifungal activity, achieving up to 74.68% inhibition against seven plant pathogenic fungi, including P. digitatum NKP4321. Bacterial culture filtrates from BC-SKRU-1 (BCF BC-SKRU-1) at 5–10% concentrations inhibited NKP4321 mycelial growth in PDB medium (78.41–83.68%) more effectively than in PDA medium (46.20–72.61%), with complete suppression at 15% (v/v) in both media. BCF BC-SKRU-1's efficacy was comparable to chemical fungicides such as propiconazole®, prochloraz®, and mancozeb®. Notably, BCF BC-SKRU-1 retained its antifungal activity after dilution (1/1000), autoclaving (at 121 °C), and storage (at −20 °C). In vivo evaluations on tangerine fruit showed significant reduction in the severity of postharvest green mold disease with BC-SKRU-1 treatments, especially at a concentration of 108 CFU mL−1. Both preventive and curative applications were effective, with curative treatments being more successful. Mechanistic studies indicated that BCF BC-SKRU-1 reduces intracellular ergosterol content, compromises plasma membrane integrity, and attenuates antioxidant defense activities (SOD, CAT, GSH, GSSG, and GSH/GSSG ratio). These findings highlight BC-SKRU-1 and its metabolites as promising biocontrol agents against green mold in tangerine fruits and provide insights into their antifungal mechanisms.

Biocontrol efficacy of Botrytis cinerea on postharvest tomato fruit by the endophytic bacterium Bacillus velezensis BE1

Endophytic bacteria offer numerous advantages in the control of postharvest diseases. Bacillus velezensis has been identified as a promising biocontrol agent against postharvest pathogens in various fruits and vegetables. In this study, B. velezensis BE1 was identified by 16S rRNA sequencing and caused 76.9 % inhibition against Botrytis cinerea in dual culture assay. The cell-free culture filtrate (CFCF) of B. velezensis strongly inhibited the growth, spore germination, and germ tube elongation of B. cinerea. Moreover, 11 bioactive compounds were identified in the CFCF using gas chromatography-mass spectrometry, and phthalic acid, dioctyl ester was the predominant component by 72.92 %. Scanning and transmission electron microscopy observations revealed that the CFCF causes irreversible morphological and ultrastructural damage to the fungal hyphae and conidia, including deformed, wrinkled, lysis, collapse, and degradation of cytoplasmic organelles. The incidence and severity of gray mold were significantly suppressed after applying CFCF at 50 % in tomato fruit. The application of CFCF caused an increase in the total phenolics and flavonoids content in tomato fruit compared with the control throughout the experiment. Furthermore, the activities of enzymes associated with defense such as phenylalanine ammonia-lyase, polyphenoloxidase, and peroxidase were significantly higher in the treated tomatoes relative to the untreated group. These results indicate that B. velezensis BE1 has significant potential as an effective biocontrol agent against the pathogen B. cinerea, offering a valuable approach for controlling gray mold in postharvest fruit.

Induced resistance to control postharvest stem-end rot by methyl jasmonate in mango fruit

Induced resistance is an alternative disease control strategy for postharvest fruits and vegetables. Methyl jasmonate (MeJA) is a crucial phytohormone in the defense response to biotic and abiotic stresses. The effect and relevant mechanism of MeJA on the control of postharvest disease in mango fruit remain unclear. This study investigated the effect and possible mechanism of MeJA against stem-end rot caused by Lasiodiplodia theobromae in mango fruit. The results showed that MeJA significantly inhibited the lesion expansion on mango fruit inoculated with L. theobromae. 10 μM MeJA treatment effectively induced disease resistance against L. theobromae during postharvest storage. MeJA enhanced the activities of defense-related enzymes, including phenylalanine ammonia lyase (PAL), peroxidase (POD), β-1,3-glucanase (GLU), and chitinase (CHT), increased the accumulation of endogenous jasmonic acid (JA) and salicylic acid (SA) contents, up-regulated the expressions of the related genes on JA pathway (AOS, JAR1, MYC2, and COI1) and SA pathway (ICS, and PR1), stimulated the contents of total phenolics and flavonoids, and inhibited the accumulation of malondialdehyde (MDA). Furthermore, MeJA delayed the ripening and senescence of the fruit by inhibiting the peel yellowing, flesh softening and change in soluble solids content (SSC) of mango fruit. The results indicated that the enhanced resistance of MeJA-treated mango to stem-end rot was potentially due to the activation of defense responses induced by synergistic interaction between JA and SA pathways, as well as delayed postharvest ripening. The MeJA treatment is a promising strategy to control stem-end rot of mango fruit.

Preparation and application of polycaprolactone/β-cyclodextrin/gamma-Decalactone nanofiber composites in citrus postharvest diseases

Citrus fruits are highly susceptible to pathogenic fungal infections after harvesting, which causes serious economic losses. Therefore, it's necessary to develop new antifungal packaging. In this study, gamma-Decanolactone (DL) was successfully encapsulated in a polycaprolactone (PCL)/β-cyclodextrin (β-CD) composite system using electrostatic spinning technology. PCL/β-CD was compounded in different ratios, the ratio was screened through other indicators such as fiber morphologies and mechanical properties. Then, antifungal mats were prepared by adding different concentrations of DL to the PCL/β-CD solution. The results showed that when the mixture ratio of PCL/β-CD was 6:1 and loaded with 6 % DL, the antifungal felt had strong mechanical, significantly inhibiting the growth of three citrus pathogens (P. digitatum, P. italicum and G. candidum), released DL for up to 204 h and effectively reduced the morbidity rate of citrus fruits. Therefore, the antifungal pad prepared in this study has great potential in the field of citrus disease control.

Molecular and metabolic insights into the mechanism of exogenous methyl jasmonate in enhancing the postharvest resistance of kiwifruit to Botrytis cinerea

Gray mold, caused by Botrytis cinerea infection, significantly impacts postharvest kiwifruit, leading to spoilage and food safety issues. Meanwhile, methyl jasmonate (MeJA) induces defense responses in plants. This study aimed to identify the optimal MeJA concentration to induce disease resistance in kiwifruits. Notably, various plant defense enzymes were detected in MeJA-treated kiwifruit. Moreover, 0.01 mol/L MeJA was found to enhance B. cinerea resistance in kiwifruit by increasing antioxidant enzyme activity. Widely targeted metabolomics analysis revealed 62–64 differentially expressed metabolites (DEMs) between the different treatment groups. Additionally, RNA-seq analysis revealed 930–2900 differentially expressed genes (DEGs), between these groups. Subsequently, combined DEG and DEM analysis highlighted phenylpropanoid biosynthesis and plant hormone signaling as key transduction pathway associated with MeJA-induced resistance. Overall, these findings identified the mechanism of MeJA-induced resistance in kiwifruit, providing a theoretical basis for the safe and effective control of postharvest diseases in kiwifruit.

Biocontrol of Fusarium oxysporum-infested Gastrodia elata Bl. by Lactobacillus curvatus 2768-VOCs and mechanism of inhibition

Gastrodia elata Bl. Is susceptible to infestation by the fungus Fusarium oxysporum, which can cause severe post-harvest diseases. This paper presents the findings of an investigation into the control and bacteriostatic mechanisms of Lactobacillus curvatus 2768-VOCs on F. oxysporum-infected G. elata. The results of both in vitro and in vivo tests demonstrated that L. curvatus 2768-VOCs exhibited inhibitory effects against F. oxysporum, with inhibition rates of 63.37% and 44.4%, respectively. The results of the in vivo test also demonstrated that the pre-fumigation approach exhibited superior efficacy compared to direct fumigation, with the former showing a preventive effect. Furthermore, it was discovered that VOCs disrupted the integrity of F. oxysporum cell membranes and altered their permeability, resulting in the leakage of cell contents. The fumigation caused damage to the mycelial structure, accompanied by a notable decline in the total lipid and ergosterol content, and an appreciable increase in MDA content. Moreover, the fumigation of VOCs markedly diminished the activities of ATPase and mitochondrial dehydrogenase, thereby disrupting the respiration of F. oxysporum and its energy metabolism. The VOCs were subjected to GC-MS analysis, which revealed that the relative content of acids was the highest, particularly formic acid and glyoxalic acid. The study offers a theoretical basis for the biological control of postharvest diseases in G. elata.