Search Results (759)

Durian (Durio zibethinus Murray) is Thailand’s most economically significant fruit export, yet foliar diseases pose a major threat to productivity and crop quality. Early-stage symptoms of several durian leaf diseases are visually similar, making reliable diagnosis difficult for farmers and even trained agronomists. This study aims to develop and evaluate an automated deep learning-based system for durian leaf disease classification under realistic field conditions. A dataset of 6119 leaf images representing six classes—Leaf_Healthy, Leaf_Colletotrichum, Leaf_Algal, Leaf_Phomopsis, Leaf_Blight, and Leaf_Rhizoctonia—was compiled from public datasets and field-collected samples. Six convolutional neural network (CNN) architectures—ConvNeXt, ResNet, DenseNet201, InceptionV3, EfficientNet-B3, and MobileNetV3—were benchmarked using a unified transfer-learning training protocol. Class imbalance was addressed using weighted cross-entropy loss, and performance was evaluated on a stratified held-out test set using accuracy, precision, recall, and F1-score metrics. The results show that ConvNeXt achieved the highest performance with 98.00% accuracy and a weighted F1-score of 0.98, followed by ResNet (96.82%) and DenseNet201 (96.09%), while efficiency-oriented models plateaued near 91%. Confusion matrix analysis revealed consistent misclassification among visually similar disease categories—Leaf_Algal, Leaf_Blight, and Leaf_Phomopsis—indicating biological similarity in lesion appearance rather than model limitations. The best-performing model was deployed as a publicly accessible web application using Gradio, enabling real-time disease diagnosis with an average inference time of approximately 0.54 s per image. Unlike prior studies, this work combines large-scale architecture benchmarking, class imbalance mitigation, and real-world deployment within a single unified framework. These findings demonstrate that modern CNN architectures can provide highly accurate and scalable disease detection tools, supporting precision agriculture by enabling early diagnosis, reducing inappropriate pesticide use, and improving decision-making for durian farmers. Full article

Mango (Mangifera indica L.), a major tropical fruit crop, suffers severe anthracnose damage caused by Colletotrichum spp., and traditional chemical control has environmental and food safety risks, with plant-microbe interaction-based biological control as a sustainable alternative. However, the regulatory role of phyllosphere microbiota in the tripartite interactions among mango, beneficial microbes and Colletotrichum remains unclear. This study explored phyllosphere microbiota’s function in mango resistance to Colletotrichum and clarified the biocontrol mechanism of key beneficial isolates. We found Colletotrichum infection significantly reshaped mango leaf endophytic and epiphytic microbial communities, enriching Burkholderia, Acinetobacter, Bacillus and other dominant genera. We isolated a B. subtilis strain L-1 from the epiphytic microbiota that was 18-fold enriched in Colletotrichum-infected mango leaves. This strain exhibited potent antagonistic activity against Colletotrichum siamense with a relative inhibition rate of 82.10%, and delivered 79.77% biocontrol efficacy on mango leaves via two synergistic pathways: inhibiting pathogen spore germination and penetration by producing antimicrobial secreted metabolites and volatile organic compounds, and enhancing host disease resistance. Our findings advance the understanding of plant-phyllosphere microbiota-pathogen tripartite interactions and provide elite microbial resources for sustainable anthracnose management. Full article

Ipê trees (Bignoniaceae), mainly belonging to the genus Handroanthus, are widely used in urban landscaping and reforestation programs in Brazil. Anthracnose, typically associated with species of Colletotrichum, represents one of the major diseases affecting ipê seedlings and ornamental trees. However, the etiological agents involved have not yet been fully clarified using modern phylogenetic tools. In this study, we identified Colletotrichum species associated with anthracnose in ipê trees from Pernambuco, Brazil. A total of 22 isolates were obtained from symptomatic leaves of Handroanthus impetiginosus and H. chrysotrichus. Species identification was based on multilocus phylogenetic analyses using CAL, GAPDH, GS, and TUB2 loci. The isolates were assigned to three species: Colletotrichum siamense, C. tropicale, and C. karsti. Colletotrichum siamense was the most prevalent species (50%), followed by C. tropicale (36.3%), while C. karsti represented 13.7% of the isolates. Pathogenicity tests confirmed that all isolates were pathogenic to both ipê species, producing typical anthracnose symptoms. Aggressiveness differed between hosts, with H. impetiginosus showing higher susceptibility, as indicated by larger lesion development, whereas H. chrysotrichus exhibited lower disease aggressiveness. Thus, our findings represent the first multilocus-based identification of Colletotrichum species causing anthracnose in ipê trees, providing new insights into the diversity and epidemiology of this disease in urban environments. Full article

Chilli is a major horticultural crop in tropical and subtropical regions that contributes substantially to the global culinary and economic sectors. However, anthracnose remains one of the most destructive diseases, causing severe losses in both field and stored fruits. Current management strategies offer limited long-term effectiveness, highlighting the need for sustainable alternatives. This study developed nanoemulsions (NEs) from Garcinia atroviridis fruit extract and evaluated their biocontrol potential against Colletotrichum capsici alone and in combination with Trichoderma harzianum. Two formulations, NE4 and NE7, exhibited good thermostability without phase separation at 25 and 54 °C, with droplet sizes of 135.1 and 124.1 nm, respectively, and were non-phytotoxic to chilli seedlings. In vitro, the nanoemulsions significantly suppressed C. capsici mycelial growth (62%) compared to the crude extract. Under rain shelter conditions, NE integrated with T. harzianum (T7 and T8) was highly effective in delaying disease onset and reducing disease severity, achieving 90.07% and 88.37% relative disease reduction, respectively. These treatments also produced the highest marketable yields, comparable to the synthetic fungicide Dithane M-45^® (2 g L⁻¹). In contrast, the untreated control group exhibited an 83% yield loss. The results indicate that nanoemulsions of G. atroviridis fruit extract, particularly when combined with T. harzianum, offer a promising and sustainable biological control option for managing pre-harvest chilli anthracnose. Their incorporation into integrated pest management programmes may reduce dependence on chemical fungicides and support safer chilli production systems. Full article

Persea americana (avocado) is a fruit rich in nutrients; however, its industry is facing major threats from pathogen infection. Here, we clearly identified Colletotrichum fructicola as the pathogen causing avocado diseases in Pu’er City, Yunnan Province. However, the biological characteristics, genetic transformation system, and early cell cycle regulation of this pathogen remained unclear. In this study, C. fructicola exhibited a maximum growth rate on complete medium (CM), with the conidial yield reaching 2 × 10⁵ conidia/mL after 24 h in liquid CM. Conidia of C. fructicola had nearly fully germinated at 4 h post-inoculation (hpi), with the appressorium formation rate exceeding 95% at 12 hpi. We also established a PEG-CaCl₂-mediated genetic transformation system. The GFP-tagged transformants showed no significant differences in core biological function from the wild type. Using eGFP labeling, we visually elucidated the early cell cycle regulation of C. fructicola. Furthermore, cell cycle inhibitor assays demonstrated that C. fructicola conidial germination is independent of nuclear division and relies on cytoskeletal modulation, whereas appressorium formation and mycelial expansion require functional cell cycle regulation. This is probably the first study to systematically elucidate the cell cycle regulatory characteristics of C. fructicola isolated from avocado, and to successfully develop its genetic transformation system. These results provide important theoretical and technical support for the formulation of integrated control strategies against C. fructicola, as well as facilitating the sustainable development of the avocado industry. Full article

Biopolymer-based packaging films possess outstanding performances and are being developed as the alternatives to traditional petroleum-based plastic packaging films with many non-ignorable shortcomings. In this study, chitosan, succinylated pullulan (SP), and berberine (BBR) were combined to fabricate novel biopolymer-based composite films (CSSPB) via the layer-by-layer assembly method. The effects of the incorporation of BBR on the physicochemical properties of the film were investigated. It was found that after BBR was added, the tensile strength (TS), elongation at break (EAB), hydrophobicity, and antioxidant capacities of the film were enhanced. The chemical bonding, crystalline properties, elemental composition, and thermal stability of the films were also characterized by Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA), respectively. The in vitro antifungal tests revealed the antifungal activities of the films with a relatively high BBR content against Colletotrichum gloeosporioides (CG). In the preservation experiments, the CSSPB films exhibited preservation effects on fresh-cut apples, which manifested as delaying browning, weight loss, an increase in the soluble solids content, and a decrease in hardness. The new CSSPB composite films were opined to hold application potential in the field of food packaging. Full article

Plant growth-promoting rhizobacteria (PGPR) have been collected and used to promote plant growth and enhance disease tolerance of various crops. In the current work, Pseudomonas aeruginosa CAKS2, an endophytic strain isolated from the rhizosphere of sweet orange, exhibited both growth promotion and antimicrobial activities. Under the in vitro condition, the CAKS2 showed multiple plant growth-promoting properties such as phosphate, potassium, and calcium solubilization, nitrogen fixation as well as production of siderophores, IAA, ammonia, exopolysaccharides, hydrogen cyanide, and biofilm formation. This P. aeruginosa strain inhibited the growth of different tested fungal and bacterial pathogens. Under the in vivo condition, the CAKS2 enhanced sweet orange plant growth, indicated by increases in the root and shoot lengths, the leaf number, and the total biomass. The biochemical components and the transcription levels of genes related to plant hormone biosynthesis were altered in the CAKS2-inoculated sweet orange. Under the in vivo infection of C. gloeosporioides, the CAKS2 reduced the diameter of lesions on orange leaves and harvested fruits and decreased disease severity and incidence at the whole plant level. The whole genome sequence of CAKS2 showed the presence of candidate genes involved in different molecular pathways contributing to plant-promoting and biocontrol properties. Importantly, certain changes in the expression of gene response for plant growth promotion and biocontrol were observed when the CAKS2 was exposed to sweet orange root exudates. This study highlights P. aeruginosa CAKS2 as a potential PGPR strain for enhancing plant growth and C. gloeosporioides tolerance in sweet orange and other citrus plants. Full article

Fungal diseases represent one of the major threats to citrus production, such as anthracnose caused by Colletotrichum gloeosporioides and Fungal Trunk Diseases (FTDs) associated with Botryosphaeriaceae, with Neofusicoccum parvum being the most prevalent species. In response to the need to reduce chemical fungicide use, this study evaluated the antifungal activity of essential oil-based nanoemulsions (N-EOs) as alternative management methods. Seven N-EOs (citronella, clove, fennel, garlic, laurel, lavender and peppermint) were first screened in vitro against multiple isolates of both pathogens through mycelial growth and conidial germination assays. Based on estimated EC₅₀ and EC₉₀ values, clove and garlic N-EOs exhibited the highest inhibitory activity, while lavender displayed intermediate but promising efficacy, particularly against N. parvum. These N-EOs were subsequently evaluated in vivo on lemon fruits inoculated with C. gloeosporioides and on detached lemon twigs inoculated with N. parvum. In vivo assays largely confirmed the in vitro trends, with clove and garlic significantly reducing lesion development. In contrast, lavender displayed limited efficacy under in vivo conditions. The phytotoxic effects at higher concentrations limited the range of applicable doses. Overall, the results suggest that N-EOs, particularly those based on clove and garlic, may offer potential as alternative tools for citrus disease management. However, host tissue interactions, formulation stability, volatility, and validation under field conditions remain critical aspects requiring further investigation. Full article

Background/Objectives: Microbial infections represent a major challenge in the food processing chain. Postharvest fungal control has historically relied on chemical control; however, their use is increasingly restricted due to environmental and health risks. Therefore, the aim of this study was to evaluate the antifungal potential of essential oils obtained from high-yield plant species and characterize the potential mechanisms of action of their major volatiles, with the goal of proposing a prospective formulation for the control of postharvest fungi. Methods: Cinnamon, rosemary, allspice, and Peruvian pepper essential oils were extracted by hydrodistillation, tested against Botrytis cinerea and Colletotrichum sp., and analyzed by gas chromatography-mass spectrometry. Finally, in silico bioactivity analyses were performed on the most abundant volatiles. Results: Cinnamon and rosemary produced the most effective oils against both fungal species. Cinnamaldehyde, cinnamyl acetate, eugenol, methyleugenol, (+)-2-bornanone, eucalyptol, α-phellandrene, and β-myrcene were some of the most abundant volatiles in the analyzed oils. In silico analyses predicted 56 antifungal mechanisms, including inhibition of cell membrane and wall synthesis, affectation of primary metabolism, inhibition of molecular processes, redox homeostasis, and protein degradation and cutinase inhibition. The last one is a specific mechanism mediating in vivo plant-fungal interactions found exclusively in β-terpinene and β-ocimene. Conclusions: Compounds with cutinase inhibition activity such as β-terpinene and β-ocimene are of great potential to complement the activity of other bioactive compounds. According to literature and in silico analyses the mixture of cinnamaldehyde, eugenol, β-terpinene and β-ocimene could be a potential formulation for the management of postharvest fungi. Full article

The aroma quality of grape fruit is a crucial trait for table grapes, yet its relationship with plant disease resistance remains unclear. Using ‘Shine Muscat’ grapes as material, this study employed HS-SPME-GC-MS combined with odor activity value (OAV) and PLS-DA analysis to investigate the regulatory effects of different rootstocks and GA₃/MeJA treatments on volatile aroma compounds. Linalool and α-terpineol were selected as representative compounds for antibacterial experiments and gene expression analysis of terpenoid synthesis. Results indicate that the Lot rootstock and 15.25 mg·L⁻¹ GA₃ treatment significantly promoted the accumulation of terpenoid aroma compounds. Linalool exhibited significant inhibitory effects on the mycelial growth of Colletotrichum fructicola and induced upregulation of DXS, TPS56, and TPS gene expression. This study reveals a potential link between aroma metabolism and defense responses, providing a theoretical basis for synergistic optimization of grape aroma quality improvement and disease-resistant cultivation. Full article

Peroxisomes are ubiquitous eukaryotic organelles that play critical roles in the infection processes of many plant pathogenic fungi. Peroxisome biogenesis depends on peroxins encoded by PEX genes. Pex8 is a fungus-specific peroxin present only in yeasts and filamentous fungi. In this study, we investigated the function of CoPEX8 in the cucumber anthracnose fungus Colletotrichum orbiculare using targeted gene deletion. Fluorescence microscopy using red fluorescent protein fused to peroxisomal targeting signal 1 (PTS1) showed that matrix protein import was abolished in the ΔCopex8 mutant. Compared with the wild-type strain, the ΔCopex8 mutant lacked detectable peroxisomes and exhibited severe defects in melanin production, fatty acid utilization, cell wall integrity, osmotic stress tolerance, and reactive oxygen species (ROS) scavenging. Deletion of CoPEX8 also reduced conidiation and impaired appressorium formation. Pathogenicity assays on cucumber leaves revealed that lesions produced by the ΔCopex8 mutant were significantly smaller than those caused by the wild-type strain. These results demonstrate that CoPEX8 is indispensable for peroxisome biogenesis and is essential for both development and virulence of C. orbiculare. Full article

Peroxisomes are ubiquitous organelles that play vital roles in various physiological and biochemical processes, including fatty acid β-oxidation and reactive oxygen species (ROS) metabolism. These organelles have been implicated in the pathogenicity of many plant fungal pathogens. In this study, CaPex8, a homolog of Saccharomyces cerevisiae Pex8, was identified and characterized in Colletotrichum aenigma. CaPEX8 was found to localize to peroxisomes, and its deletion impaired the mutant’s ability to utilize fatty acids as a carbon source. Using a green fluorescent protein (GFP) fused to the peroxisomal targeting signal PTS1, the import of peroxisomal matrix proteins was shown to be defective in ΔCapex8 mutants. Additionally, the mutants exhibited elevated conidiation, increased sensitivity to osmotic stress and oxidative stress, and impaired cell wall integrity. Peroxisome biogenesis was also disrupted in the absence of CaPEX8. Taken together, these results demonstrate that CaPex8 is essential for maintaining peroxisomal structure and function, and it significantly influences fungal growth, development, and pathogenicity in C. aenigma. Full article

This study systematically identified the pathogenic fungi affecting Areca catechu in Hainan. Using diseased tissues from five regions, isolates were obtained using molecular methods, and their pathogenicity was confirmed using Koch’s postulates. We obtained 44 distinct fungal isolates from 9 genera. Fusarium (27.27%) and Colletotrichum (38.12%) were the dominant genera across all tissues. Twenty isolates were confirmed as pathogens. Key findings include the first report of Alternaria angustiovoidea and A. pogostemonis as areca leaf spot pathogens in China and the first confirmation of pathogenicity for three Fusarium species complexes (FSSC, FFSC, FIESC). Five Fusarium species are newly reported as pathogens in China. Cladosporium tenuissimum and Plectosphaerella cucumerina were confirmed for the first time to cause leaf spot. Fusarium, Colletotrichum, and Alternaria were core pathogens, all exhibiting high polygalacturonase and cellulase activity. The FFSC and Colletotrichum gloeosporioides species complex (CGSC) showed broad-spectrum pathogenicity on tropical fruits. Fungicide sensitivity assays ranked efficacy as prochloraz > difenoconazole > tebuconazole > ethylicin > pyraclostrobin, with genus-specific responses observed. This research fills a systematic knowledge gap on areca fungal diseases in China, providing a crucial basis for precise control strategies and integrated management. Full article

The common bean (Phaseolus vulgaris L.) cultivar Jalo Vermelho carries the Co-12 gene, which confers resistance to both Andean and Mesoamerican races of Colletotrichum lindemuthianum. Despite its importance for breeding programs, the genomic location and candidate genes underlying this resistance remain poorly defined. The Co-12 locus was fine-mapped using a biparental population derived from the cross Jalo Vermelho × Crioulo 159. A total of 172 F₂ plants were used to generate 172 F_2:3 families, which were phenotyped after inoculation with race 1545 of C. lindemuthianum. Segregation analysis confirmed a 1:2:1 Mendelian ratio, consistent with a single dominant resistance gene. Genotyping of resistant and susceptible plants using the BARBean6K_3 Illumina BeadChip (5398 SNP markers) mapped Co-12 to chromosome Pv04, between 1695 bp (ss715649768) and 9,651,954 bp (ss715646644). Subsequent fine mapping with simple sequence repeat (SSR) markers delimited the locus to a 41 kb genomic interval flanked by BARCPVSSR04557 and BARCPVSSR04570. Within this region, three candidate genes were identified, including one encoding a gamma-glutamyl-GABA enzyme and two encoding lipid transfer proteins (LTP2). Lipid transfer proteins are widely recognized components of plant defense; however, their association with anthracnose resistance in the common bean has not been previously reported. The identification of LTP2 genes within the Co-12 interval suggests a previously unrecognized resistance mechanism and expands the current understanding of host defense pathways in Phaseolus vulgaris. The markers identified here provide valuable tools for marker-assisted selection and will facilitate efficient introgression of Co-12 into common bean cultivars. Full article

The endangered ethnomedicinal plant Euchresta tubulosa harbors a valuable community of endophytic fungi, demonstrating significant potential for biotechnological applications. Endophytic fungi were isolated from E. tubulosa and identified to characterize their secondary metabolites and extracellular enzyme activities. Endophytic fungi were isolated from E. tubulosa using tissue explant culture and identified by morphological and molecular (ITS) analysis. The chemical profiles of strain fermentation products were analyzed by LC–MS/MS, while extracellular enzyme production (cellulase, protease, amylase) was assessed through chromogenic plate assays and liquid fermentation. The results indicated that a total of 55 endophytic fungi were isolated from E. tubulosa, assigned to 17 genera. Among these, three genera (Colletotrichum, Fusarium, and Penicillium) constituted the dominant groups, while four strains (including three novel species) represented potential new taxa. LC–MS/MS analysis revealed that fermentation products of the three novel endophytic fungal species contained bioactive compounds such as flavonoids and alkaloids; furthermore, bioactivity assays indicate that they exhibited significant degrees of antibacterial and antioxidant activity. Extracellular enzyme assays demonstrated that three E. tubulosa-derived endophytic strains exhibited multi-hydrolytic enzyme production capabilities. Notably, strain ETG-1-2-1 showed the highest amylase and cellulase activities (10.95 U/mL and 9.68 U/mL, respectively), while strain ETXG-1-1-1 displayed the highest protease activity (2.34 U/mL). This study provides the first systematic report on the diversity of endophytic fungi in E. tubulosa, their secondary metabolite profiles, and extracellular enzyme activities, establishing a theoretical foundation for discovering novel bioactive compounds and developing microbial resources, while also highlighting their ecological roles and biotechnological potential. Full article