Search

A major problem for St John's wort (Hypericum perforatum) is St John's wilt, which can lead to reduced crop yields and even complete crop losses. In the past, the pathogen was referred to as Colletotrichum gloeosporioides or occasionally as Colletotrichum cf. gloeosporioides based on morphology. Although a strain from this host had been re-identified as C. cigarro in taxonomic studies, there is uncertainty about the identity of the St John's wilt pathogen, which is generally still addressed as C. gloeosporioides in applied science. In a multi-locus [internal transcribed spacer (ITS), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), actin (ACT), and glutamine synthetase (GS)] analysis of the C. gloeosporioides species complex, all isolates obtained from newly collected symptomatic H. perforatum stems and seeds from Germany and Switzerland were identified as C. cigarro. Although they belonged to the same haplotype, the morphology of the isolates was very variable. Pathogenicity tests demonstrated that only C. cigarro strains from H. perforatum cause symptoms on H. perforatum , whereas other Colletotrichum species tested only caused latent infection of H. perforatum. [ABSTRACT FROM AUTHOR]

Lucky bamboo (Dracaena sanderiana hort. ex. Mast. = Dracaena braunii) is a popular decorative plant in China. In March 2022, a severe outbreak of anthracnose disease occurred on the stems of lucky bamboo plants in a nursery garden in Nanjing, Jiangsu Province, China. Thirty-two fungal isolates were obtained from the infected stem tissues and were morphologically identified as Colletotrichum species. A multilocus phylogenetic analysis based on the internal transcribed spacer (ITS) region, the actin (ACT) gene, and the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene indicated the isolate FGZ-1 as Colletotrichum gloeosporioides (Penz.) Penz. and Sacc. The pathogenicity of isolate FGZ-1 was verified by inoculating mycelial plugs on stem segments and spraying spores on the whole one-year-old lucky bamboo plants. Koch's postulates were fulfilled via the re-isolation of C. gloeosporioides from the diseased tissues. To the best of our knowledge, this is the first report of C. gloeosporioides causing anthracnose on lucky bamboo in China. The detection of C. gloeosporioides on lucky bamboo in China expands the range of Colletotrichum species that are associated with anthracnose in this popular ornamental plant. This study lays a solid foundation for future investigations into the pathogenic mechanisms of anthracnose on D. sanderiana and control strategies for this disease, such as biocontrol agents and the construction of resistant cultivars. [ABSTRACT FROM AUTHOR]

Active packaging has emerged as a promising technological alternative for coating fruits and extending their shelf life. In this study, we developed a Tara gum and chitosan nanostructure-based coating, assessing its effects on guava shelf life and antifungal activity. In vitro analyses showed that nanochitosan suspension concentrations between 4.5 and 5.625 mg·mL−1 completely inhibited the growth of the fungus Colletotrichum gloeosporioides and reduced the growth of Puccinia psidii. In in vivo tests, guavas coated with a 1.5% (w/v) Tara gum coating with 0.5% (v/v) nanochitosan exhibited significantly delayed or no lesion growth, unlike the control group, where lesions developed continuously. Beyond antifungal results, the Tara gum and nanochitosan coatings maintained the guava's luminescence for up to 16 days, reduced weight loss, and preserved firmness compared to the control group. Firmness tests indicated that Tara gum, both pure and at 0.1% and 0.3% (v/v) concentrations, was effective in preserving this characteristic. Chemically, the coating also contributed to increased pH and acidity of the guavas, although a reduction in reducing and total sugars was observed in all groups. These findings confirm that the Tara gum with nanochitosan-based coating is an effective nanotechnological biomaterial to extend the shelf life of seasonal fruits, acting as a physical and biological barrier against pathogens and supporting post-harvest preservation. [ABSTRACT FROM AUTHOR]

Anthracnose caused by Colletotrichum gloeosporioides is a major postharvest disease of mango. Melatonin (MT) is an endogenous plant hormone that plays a crucial role in both biotic and abiotic stress responses. The objective of this study was to explore the impact of MT treatment on anthracnose disease of "Tainong" mango fruit through both in vivo and in vitro experiments. In vivo tests showed that 0.2 mmol L−1 MT clearly postponed the occurrence of anthracnose and effectively reduced the lesion diameter on inoculated mango fruit. However, in vitro tests showed that MT had no significant effects on mycelium growth and spore germination of C. gloeosporioides. Further in vivo analysis demonstrated that MT significantly increased the activities of enzymes involved in phenylpropanoid metabolism and pathogenesis related proteins, as well as the contents of flavonoids, anthocyanins, lignin and total phenols in mango fruit. MT treatment caused an obvious production in the initial hydrogen peroxide (H2O2) and nitric oxide (NO) contents in inoculated mango fruit, while it decreased their content at later stages by enhancing the activities of antioxidant enzymes. Furthermore, MT significantly reduced the activity of cell-wall hydrolases and the soluble pectin content, and slowed down the loss of cellulose and protopectin. Principal constituent analysis (PCA) and correlation analysis showed that MT enhanced the resistance of mango fruit to C. gloeosporioides by enhancing defense enzyme activities and the contents of secondary metabolites and inhibiting pectin hydrolysis. In summary, MT can be an effective alternative to fungicides aimed at controlling postharvest anthracnose. [ABSTRACT FROM AUTHOR]

Introduction: Grapevine (Vitis vinifera L.), one of the economically important fruit crops cultivated worldwide, harbours diverse endophytic bacteria (EBs) responsible for managing various fungal diseases. Anthracnose (Colletotrichum gloeosporioides) (Penz.) is one of the major constraints in quality grape production and therefore its management is a major concern among the grape growers. Materials and methods: Among the 50 EBs isolated from healthy leaf segments from the eight grapevine genotypes, biologically potential 20 EBs were purified and identified based on morphological, and biological characteristics and sequence analysis of 16S rRNA region. The antagonistic activities of EBs against Colletotrichum gloeosporioides were studied in vitro conditions. Results: The colony morphologies of EBs are white and yellow-coloured colonies, circular to irregular in shape, and entire, and flat margins. Among the 20 purified EBs, 19 isolates were found to be Gram-positive except one i.e., MS2 isolate. The 12 isolates reduced nitrate and 14 isolates produced urease enzyme. The in vitro assay revealed that two isolates, SB4 and RF1, inhibited 56.1% and 55.6% mycelial growth of C. gloeosporioides , respectively. Further, the identity of EBs was confirmed through PCR amplification of the 16S rRNA region resulting in ~1400 bp size amplicons. The sequence analysis of representative 15 isolates revealed that 5 EB isolates viz., SB5, CS2, RG1, RF1, C1 were identified as Bacillus subtilis with >99% sequence identity, two EBs viz., SB3, and CS1 were identified as B. subtilis subsp. subtilis , two EBs viz., SB1, and CS4 were identified as B. licheniformis. The SB2 isolate was identified as Bacillus sp., whereas SB4 as Brevibacillus borstelensis , TH1 as B. velezensis , TH2 as B. tequilensis , CS3 as B. pumilus and MS1 as Micrococcus luteus were identified. Conclusion: The phylogenetic analysis of 16S rRNA sequence revealed eight distinct clades and showed the close clustering of identified species with the reference species retrieved from NCBI GenBank. The current investigation provides the scope for further field evaluations of these endophytic microbes for managing anthracnose disease. [ABSTRACT FROM AUTHOR]

Colletotrichum species are the causal agents of grape ripe rot (GRR). However, Colletotrichum isolates have been isolated from symptoms of leaf grape anthracnose (GA) caused by Elsinöe ampelina infection. Thus, the present study aimed to evaluate whether Colletotrichum isolates obtained from grapes with GA are pathogenic on grapevine leaf, cane, or berry causing GA, or if they can cause GRR symptoms on ripe grapes. Colletotrichum isolates were characterized by genetic and morphological analyses as well as pathogenicity tests. One isolate of E. ampelina from GA and one of Colletotrichum acutatum complex (GL1) collected from GRR symptoms were used as reference isolates. Colletotrichum isolates from GA lesions were identified by genetic and morphological differences as C. nymphaeae (17 isolates) and C. theobromicola (one isolate). C. theobromicola was found for the first time associated with grapes in Brazil. C. nymphaeae and C. theobromicola did not cause lesions on grapevine leaf or cane, but the isolate of E. ampelina confirmed symptoms of typical GA. The Colletotrichum isolates from leaves were pathogenic on grapevine berries leading to GRR symptoms. Epidemiological studies on the relevance of Colletotrichum latent infection on leaves as a source of primary inoculum of ripe rot and the interference of co‐infections of E. ampelina × Colletotrichum spp. on GA symptoms should be further investigated. [ABSTRACT FROM AUTHOR]

The role of some Colletotrichum species is uncertain in crops of economic importance for Colombia such as mango (Mangifera indica L.) cv. Azúcar. Eight Colletotrichum isolates from asymptomatic plant tissues were characterized by their pathogenicity on fruits and identified by phylogenetic analysis of the sequences of the ITS, GADPH, Tub2, CHs-1 and Act genomic regions. Colletotrichum asianum, C. gloeosporioides and C. tropicale of the C. gloeosporioides species complex and C. karstii of the C. boninense species complex were identified. The highest virulence was observed for isolates of C. asianum, that was the most prevalent species, and for C. tropicale, that showed high and intermediate virulence levels, indicating diversity in pathogenicity within the same species. The isolate of C. karstii, which displayed intermediate virulence, is the first report on mango in Colombia. Colletotrichum gloeosporioides presented intermediate virulence and was isolated at a low frequency in the present research. The mycelial growth rate did not show differences between species and ranged between 6.1 and 8.3 mm per day. Colletotrichum asianum recorded higher values of conidia germination and appressoria formation than other species, at 77% and 79%, respectively (p < 0.001). The shape and size of conidia did not vary between species. Appressoria exhibited different shapes between isolates and the largest average diameter was for C. karstii with 7.6 µm (p < 0.001). There was a diversity of Colletotrichum species associated with mango cv. Azúcar in Colombia, with differential virulence among isolates of the same species. [ABSTRACT FROM AUTHOR]

Anthracnose, caused by Colletotrichum spp., is a threat to strawberry production globally. Unlike their chemical counterparts, microbial biofungicides offer a method of postharvest fungal disease control that is safe, sustainable and less affected by pathogen resistance. The present study evaluated the antifungal effects of three bacteria, Bacillus velezensis strains SH1 and SH2 and Pseudomonas azotoformans strain SH3, obtained from sheep manure compost tea. The bacteria or their cell‐free filtrates were tested against Colletotrichum acutatum and Colletotrichum gloeosporioides in bioassays and against strawberry anthracnose. In addition, precipitated or extracted extracellular fractions were tested to determine the effects on membrane permeability of Colletotrichum spp. spores. Confrontation assay results showed all bacteria inhibited mycelial growth, with B. velezensis SH1 and P. azotoformans SH3 being the most effective. All cell‐free filtrates inhibited mycelial growth with B. velezensis SH1 and SH2 resulting in the highest inhibition. The bacteria suppressed anthracnose lesions on strawberry fruit although effective treatments varied by causal mould. B. velezensis SH1 and SH2 significantly permeabilized spore membranes, indicating antibiosis as a possible mode of action. Investigation into antimicrobial compound production found various homologues of the lipopeptides fengycin, iturin and surfactin were produced by B. velezensis SH1 and SH2. Results suggest that lipopeptides produced by B. velezensis strains permeabilize Colletotrichum cell membranes, and that fengycins were the most inhibitory of the lipopeptides against Colletotrichum spp. [ABSTRACT FROM AUTHOR]

A new extraction and bacteriostatic ability of glucoside alkaloids in potato peel. To make better use of glucoside alkaloids, this experiment adopted ultrasonic microwave combined extraction of glucoside alkaloids from potato peel; then, the extracts of potato peel were subjected to bacteriostatic assays. The optimum experimental condition of response surface method was that the solid-liquid ratio was 1:18.00 g/mL, the ultrasonic power 505.00 W, the microwave time was 6.10 min and the ultrasonic time was 10.70 min. Under those conditions, the extraction amount of glucoside alkaloids was 292.91 mg/kg, which increased by about 28% compared with the QUEChERS method. The antibacterial activity of the obtained glucoside alkaloids was tested using five kinds of strains, and the results showed that Penicillium and Colletotrichum gloeosporioides were more sensitive. The results indicated that Ultrasonic-Microwave combined extraction was more efficient and convenient than that of QuEChERS method for glucoside alkaloids and related antibacterial compounds from potato peel. [ABSTRACT FROM AUTHOR]

Conventional ultraviolet C at 254 nm (UVC) and Far UVC at 222 nm (Far UVC) were evaluated as alternatives to fungicides for disease control. Conidia of 13 isolates of strawberry anthracnose pathogens (five Colletotrichum species in two complexes: C. acutatum and C. gloeosporioides) were uniformly dispersed onto agar and irradiated with UVC and Far UVC doses ranging from 52 to 1,248 J·m−2. After 48 h of incubation, a UVC dose of 1,248 J·m−2 and Far UVC doses from 234 to 935 J·m−2 reduced Colletotrichum colony counts to

This study examines the effects of a hydrophobic deep eutectic oil-in-water nanoemulsion (HyDEN) on the cell membrane degradation and inhibition of Colletotrichum gloeosporioides. By analyzing post-treatment cell membrane morphology, we gain insights into the efficacy and mechanisms of action of antifungal agents. Significant changes such as disruption, collapse, wrinkling, and lysis were observed in the external morphology of C. gloeosporioides treated with HyDEN. When comparing control and treatment groups, HyDEN demonstrated more pronounced disruption and greater mycelial growth inhibition than Globus 5.5. HyDEN also effectively inhibited spore germination compared to Globus 5.5. Tests on intracellular ion leakage showed that HyDEN caused higher conductivity, indicating significant membrane disruption. Additionally, HyDEN led to a greater release of soluble sugars due to membrane damage compared to Globus 5.5. These findings suggest that HyDEN is a promising antifungal strategy, effectively disrupting cell wall and membrane functionality, and inhibiting fungal growth. [ABSTRACT FROM AUTHOR]

Abstract Anthracnose disease, caused by the Colletotrichum gloeosporioides species, affects vegetables, fruits, pulses, and cereals, leading to significant economic losses worldwide. Although many synthetic fungicides are used to control this pathogen, eco-friendly biological alternatives are gaining popularity. This study focuses on isolating and purifying chitinase ( Af Chi)from a marine bacterium and testing its antifungal efficacy against C. gloeosporioides spore germination by targeting the chitin in the fungal cell wall. The chitinase was purified from a marine bacterium A. faecalis from the Arabian Sea and had a molecular mass of 45 kDa and a specific activity of 84.6 U/mg. Af Chi worked best at 50 °C and pH 7.0 in Tris HCl buffer. Na+ ion was the highest cofactor, highlighting the halophilic nature of this chitinase. K+, Ca2+, Cu2+, Mg2+, Mn2+, and EDTA also increased activity, while Fe3+, Zn2+, Co2+, and Pb2+ decreased it. The Km and Vmax values were 1.87 µg/mL and 17.45 U/mL, respectively. Purified Af Chi at 10 mg/mL completely inhibited spore germination within 8 h and reduced the size of the spores.

Anthracnose, caused by Colletotrichum gloeosporioides in mango production, can lead to crop losses of 60 %. Synthetic fungicides constitute its leading management strategy. We evaluated combinations of different management practices to control anthracnose in a commercial Tommy Atkins mango grove in 2015 and 2016. We followed a randomized complete block experimental design with a subdivided plot arrangement composed of 12 treatments, three replicates per treatment, and one mango tree per replicate for 36 trees. Pruning was practiced at plot level (with and without pruning), nutrients were applied to subplots (soil fertilizer, foliar nutrient application, and no nutrient supply), and at sub-subplot level, three anthracnose management treatments were given (chemical, biological, and no treatment). In 2015 and 2016, the treatments involving natural or biological applications against anthracnose plus nutrient supply led to the most significant reductions in quiescent leaf infections and disease presence in flowers and fruits. In addition, pruning at specific crop development stages improved results. In light of our results, this integrated anthracnose management approach in mango production can deliver the expected results if implemented consistently.

Abstract Background DIR (Dirigent) proteins play important roles in the biosynthesis of lignin and lignans and are involved in various processes such as plant growth, development, and stress responses. However, there is less information about VvDIR proteins in grapevine (Vitis vinifera L). Results In this study, we used bioinformatics methods to identify members of the DIR gene family in grapevine and identified 18 VvDIR genes in grapevine. These genes were classified into 5 subfamilies based on phylogenetic analysis. In promoter analysis, various plant hormones, stress, and light-responsive cis-elements were detected. Expression profiling of all genes following Colletotrichum gloeosporioides infection and phytohormones (salicylic acid (SA) and jasmonic acid (JA)) application suggested significant upregulation of 17 and 6 VvDIR genes, respectively. Further, we overexpressed the VvDIR4 gene in Arabidopsis thaliana and grapes for functional analysis. Ectopic expression of VvDIR4 in A. thaliana and transient expression in grapes increased resistance against C. gloeosporioides and C. higginsianum, respectively. Phenotypic observations showed small disease lesions in transgenic plants. Further, the expression patterns of genes having presumed roles in SA and JA signaling pathways were also influenced. Lignin contents were measured before and after C. higginsianum infection; the transgenic A. thaliana lines showed higher lignin content than wild-type, and a significant increase was observed after C. higginsianum infection. Conclusions Based on the findings, we surmise that VvDIR4 is involved in hormonal and lignin synthesis pathways which regulate resistance against anthracnose. Our study provides novel insights into the function of VvDIR genes and new candidate genes for grapevine disease resistance breeding programs.

Anthracnose disease, caused by the Colletotrichum gloeosporioides species, affects vegetables, fruits, pulses, and cereals, leading to significant economic losses worldwide. Although many synthetic fungicides are used to control this pathogen, eco-friendly biological alternatives are gaining popularity. This study focuses on isolating and purifying chitinase (Af Chi)from a marine bacterium and testing its antifungal efficacy against C. gloeosporioides spore germination by targeting the chitin in the fungal cell wall. The chitinase was purified from a marine bacterium A. faecalis from the Arabian Sea and had a molecular mass of 45 kDa and a specific activity of 84.6 U/mg. Af Chi worked best at 50 °C and pH 7.0 in Tris HCl buffer. Na+ ion was the highest cofactor, highlighting the halophilic nature of this chitinase. K+, Ca2+, Cu2+, Mg2+, Mn2+, and EDTA also increased activity, while Fe3+, Zn2+, Co2+, and Pb2+ decreased it. The Km and Vmax values were 1.87 µg/mL and 17.45 U/mL, respectively. Purified Af Chi at 10 mg/mL completely inhibited spore germination within 8 h and reduced the size of the spores. Key points: The chitinase remain stable at high temperature. The chitinase from A. faecalis shown positive result in development of natural bio-fungicide. [ABSTRACT FROM AUTHOR]

A new lactone, collectindolide (1), as well as three known compounds, (S)-sydonic acid (2), (S)-hidroxysydonic acid (3), and indole-3-aceticacid (4) were obtained from the liquid media of Colletotrichum gloeosporioides, which was obtained from Artocarpus heterophyllus. The chemical structures of 1-4 were established by spectroscopic analyses, including NMR experiments and by HR-ESI-TOF-MS mass spectroscopy. Compounds 1-4 were evaluated for their cytotoxicity against murine leukaemia P-388 cell lines by MTT assay. Antibacterial activity of compounds 1-4 was also assayed against four bacteria. Phytochemical investigation of the genus Colletotrichum derived from the plant genus Artocarpus is reported for the first time. [ABSTRACT FROM AUTHOR]

Citrus spp. represent an economically important fruit tree crop worldwide. However, molecular mechanisms underlying the interaction between citrus and the Colletotrichum gloeosporioides remain largely unexplored. In this study, we analyzed the physiological and transcriptomic changes in Citrus sinensis at different stages of incubation with C. gloeosporioides. The results indicated that C. gloeosporioides infection rapidly triggered necrosis in the epicarp of C. sinensis fruits, decreased the total flavonoid contents, and suppressed the activity of catalase, peroxidase, and superoxide dismutase enzymes. Upon inoculation with C. gloeosporioides, there were 4600 differentially expressed genes (DEGs) with 1754 down-regulated and 2846 up-regulated after six hours, while there were only 580 DEGs with 185 down-regulated and 395 up-regulated between six and twelve-hours post-inoculation. Gene Ontology and the Kyoto Encyclopedia of Genes and Genomes enrichment analysis indicated that the DEGs, which exhibited consistent up-regulation, were associated with metabolic processes and stress responses. Through Weighted Gene Co-Expression Network Analysis, 11 key genes have been identified that could potentially play a role in the transcriptional regulation of this process, including the transcription factor bHLH189. Furthermore, the infection of C. gloeosporioides had a notable effect on both the flavonoid metabolism and the metabolic pathways related to reactive oxygen species. Our findings help to understand the interaction between citrus and C. gloeosporioides and unveil how new insights into how C. gloeosporioides circumvents citrus defense mechanisms. [ABSTRACT FROM AUTHOR]

Mixing two or more essential oils (EOs) may increase effectiveness in controlling mango anthracnose. In this study, EOs from a wide range of plant materials were hydrodistilled and chemically characterized. The EOs were tested against the in vitro growth of Colletotrichum gloeosporioides. EOs with the highest antifungal toxicity were selected for interactive experiments. The results showed that orange had the highest extraction yield (4.94%), followed by lemon, pomelo, citronella, turmeric, ginger, lemongrass (LG), cinnamon bark (CB), cinnamon leaf (CL), and basil. Trans-cinnamaldehyde was the most abundant compound in the CB (91.3%) and CL (94.1%) EOs. Limonene was the principal constituent of the orange (97%), pomelo (96.1%), and lemon (67.2%) EOs. Citral (78.4%), methyl chavicol (76.1%), linalool (72.7%), and geraniol (69.1%) were the major chemicals in the LG, basil, coriander, and citronella EOs, respectively. The dominant compounds in the ginger, turmeric, and peppermint EOs were zingiberene (23.8%), ar-turmerone (33.9%), and menthol (40.8%), respectively. The LG, CB, and CL EOs had the strongest antifungal activities against fungal growth and achieved a minimum fungicidal concentration (MFC) of 2, 0.8, and 0.4 µL/mL, respectively. The mixture of LG (0.8 µL/mL) with CB (0.025 µL/mL) or CL (0.05 µL/mL) EO showed a synergistic effect against the pathogen with a MFC at lower concentrations than that of the EOs alone. Similarly, the EO mixtures had a synergistic effect on the control of mango anthracnose. CL and CB EOs alone as well as mixed with LG EO were more effective in controlling mango anthracnose than commercial fungicide. The EOs, both alone and mixed, had no or negligible effects on mango quality. In short, CL or CB EOs alone or in mixtures with LG EO can be commercially used as biofungicides to control mango anthracnose. [ABSTRACT FROM AUTHOR]

This study aimed to provide foundational research for the biological control of postharvest avocado fruits anthracnose and establish a microbial system of postharvest avocado fruits. The high-throughput sequencing of avocado fruits from the anthracnose-infected and healthy groups was performed using Illumina NovaSeq second-generation sequencing technology. The results revealed that, except for Colletotrichum sp. strain 38#, there were differences in the bacterial community structure of avocados before and after infection, as determined through alpha and beta diversity analysis. Additionally, there were significant differences in the endophytic fungal community structure, allowing clear differentiation between the infected and healthy avocados. The endophytic bacterial community was primarily composed of 4 phyla and 10 genera, with the Bacteroidota phylum and Chryseobacterium genus demonstrating sensitivity to anthracnose pathogens, as evidenced by a decrease in their relative abundance after infection. The endophytic fungal community was characterized by 3 phyla and 10 genera. After infection, the relative abundance of 2 phyla (Anthophyta and Basidiomycota) and 7 genera (Eucalyptus, Candida, Kluyveromyces, Talaromyces, Oidiodendron, Nigrospora, and Pestalotiopsis) decreased, whereas the relative abundance of the Colletotrichum genus increased dramatically. The LEfSe (Linear discriminant analysis Effect Size) analysis indicated that significant biomarkers were more prevalent in endophytic bacteria than in endophytic fungi in the avocados. In endophytic bacteria, the key biomarkers included the Firmicutes phylum (Bacilli class), Proteobacteria phylum (Gammaproteobacteria class, Pseudomonadales order, Pseudomonadaceae family, and Pseudomonas genus), Flavobacteriales order, Weeksellaceae family, and Chryseobacterium genus. In endophytic fungi, the important biomarkers were Saccharomycetes class (Saccharomycetales order), Glomerellales order (Glomerellaceae family and Colletotrichum genus), and Botryosphaeriales order (Botryosphaeriaceae family and Lasiodiplodia genus). These results may provide a theoretical basis for the development of future biological agents for avocado anthracnose. [ABSTRACT FROM AUTHOR]

In Mexico, the Ataulfo mango crop faces significant challenges due to anthracnose, a disease caused by the fungus Colletotrichum gloeosporioides. The need to use eco-friendly fungicides is crucial to avoid the use of harmful synthetic chemicals. This study aimed to prepare chitosan nanoparticles through a simple and effective ultrasound-assisted top-down method, with high antifungal efficiency. The nanoparticles were prepared from chitosan (DD = 85%, MW = 553 kDa) and Tween 20 under constant sonication. The formation of the nanoparticles was initially confirmed by Fourier-transform infrared (FTIR) spectroscopy; and their physicochemical properties were subsequently characterized using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The antifungal potential of the chitosan nanoparticles against the phytopathogen Colletotrichum gloeosporioides was evaluated with isolated fungi obtained directly from mango tissues showing anthracnose symptoms in the state of Guerrero, Mexico. The fungus was identified through SEM imaging, showing a regular and smooth conidial layer, with cylindrical shape (r = 2 µm, h = 10 µm). In vitro tests were conducted with three different concentrations of chitosan nanoparticles to assess their inhibitory effects. After seven days of incubation, a maximum inhibition rate of 97% was observed with the 0.5% nanoparticle solution, corresponding to a fungal growth rate of 0.008 cm/h. At this time, the control mycelial growth was 7 cm, while the treated sample reached a radius of 0.55 mm. These results demonstrated the antifungal effect of the nanoparticles on the membrane and cell wall of the fungus, suggesting that their composition could induce a resistance response. The inhibitory effect was also influenced by the particle size (30 nm), as the small size facilitated penetration into fungal cells. Consequently, the parent compound could be formulated and applied as a natural antifungal agent in nanoparticle form to enhance its activity. The method described in this study offers a viable alternative for the preparation of chitosan nanoparticles, by avoiding the use of toxic reagents. [ABSTRACT FROM AUTHOR]

Trade-offs between different defense traits exist commonly in plants. However, no evidence suggests that symbiotic microbes can drive a trade-off between plant pathogen and herbivore defense. The present study aims to investigate whether the mixture of epiphytic Fusarium oxysporum and Fusarium fujikuroi can drive the trade-off between the two defense traits in invasive Ipomoea cairica. Surface-sterilized I. cairica cuttings pre-inoculated with the epiphytic fungal mixture served as an epiphyte-inoculated (E+) group, while cuttings sprayed with sterile PDB served as an epiphyte-free (E−) group. After 3 days of incubation, E+ and E− cuttings were subjected to the challenge from a fungal pathogen and an insect herbivore, respectively. The results suggested that E+ cuttings had less rotted and yellowed leaf rates per plant than E− cuttings after Colletotrichum gloeosporioides infection. On the contrary, E+ cuttings had higher absolute and relative fresh weight losses per leaf than E− cuttings after Taiwania circumdata introduction. In the absence of challenges from the two natural enemies, salicylic acid and H2O2 accumulation occurred in E+ cuttings, which activated their SA-dependent pathogen defense and resulted in an increase in chitinase and β-1,3-glucanase activities. Although jasmonic acid accumulation also occurred in E+ cuttings, their JA-dependent herbivore defense responses were antagonized by SA signaling, leading to a decrease in total phenol content and phenylalanine ammonia-lyase activity. The activity of generalized defense enzymes, including superoxide dismutase, peroxidase, and catalase, did not differ between E+ and E− cuttings. Together, our findings indicate that a trade-off between pathogen and herbivore defense in I. cairica had already been driven by the epiphytic fungal mixture before the challenge by the two natural enemies. This study provides a novel insight into biocontrol strategies for I. cairica. [ABSTRACT FROM AUTHOR]

Poplar is an economically and ecologically valuable tree species. Anthracnose, which severely affects poplar tree growth, is mainly caused by Colletotrichum gloeosporioides. In the infestation cycle of poplar anthracnose, the entry of C. gloeosporioides into the host tissue depends on the formation of an appressorium. The subsequent development of the appressorium determines the pathogenesis of poplar anthracnose and the degree of damage. Previous studies have found that the transcription factor CgSte12 affects appressorium formation and development by regulating the expression of a series of genes, including the sterol-synthesis-related gene CgCYP51, which influences appressorium formation and development. In this study, knockout and functional analyses of CgCYP51 revealed decreases in differentiation, darkening rate, and turgor pressure of appressoria in mutants. Additionally, compared with the wild-type appressorium, mutant appressoria secreted less mucus and exhibited abnormal penetration pore formation, ultimately leading to decreased pathogenicity. Moreover, CgCyp51 affected the sensitivity of C. gloeosporioides to sterol biosynthesis inhibitors. Considered together, the study findings indicate CgCYP51 is a key CgSte12-regulated gene that affects C. gloeosporioides appressorium formation and development. Furthermore, the study data provide new insights into the molecular basis of C. gloeosporioides appressorium formation and development. [ABSTRACT FROM AUTHOR]

Walnut (Juglans spp.), a significant deciduous tree of economic and ecological importance, faces substantial threats from walnut anthracnose, primarily caused by Colletotrichum gloeosporioides. Bacillus velezensis has shown promise in mitigating this fungal pathogen. To delve deeper into the induction mechanism of B. velezensis on walnut plant resistance, we conducted a metabolomic analysis on walnut leaves from six different treatment groups. Specifically, the groups were defined as follows: Group B.v. was inoculated with B. velezensis alone, Group CK served as the blank control, and Group C.g. was inoculated solely with C. gloeosporioides. Group B.v.-C.g. received B. velezensis followed by C. gloeosporioides inoculation. Group B.v.+C.g. underwent simultaneous inoculation with both B. velezensis and C. gloeosporioides, while Group C.g.-B.v. was treated first with C. gloeosporioides then B. velezensis. A total of 1,503 metabolites were detected, mainly including flavonoids, terpenoids, and steroids. The results revealed that B. velezensis spraying not only enhanced the inherent resistance of walnut plants but also significantly regulated walnut plants already infected with C. gloeosporioides. This was mainly achieved by inducing walnut plants to adjust their metabolic pathways such as salicylic acid, jasmonic acid, and abscisic acid, thereby strengthening their stress response. Transcriptomic and metabolomic correlation analyses showed that in the comparisons of B.v. vs. CK, C.g. vs. CK, and C.g.-B.v. vs. C.g., 59, 244, and 122 differential abundance metabolites were detected, along with 7860, 3677, and 5587 differential genes, respectively. Amino acid synthesis, starch and sucrose metabolism, photosynthesis, phenylpropane metabolism, purine metabolism, and glutathione metabolism played crucial roles in walnut's disease resistance mechanism. Further analysis revealed that B. velezensis induced walnut plants to regulate multiple genes, such as LOC109005403, LOC108985444 and LOC118344177, resulting in the production of defensive metabolites such as palmitic acid, coumarin and ferulic acid, thereby enhancing their resistance to C. gloeosporioides. In summary, B. velezensis induces systemic resistance in walnut plants by modulating the metabolic pathways of salicylic acid, jasmonic acid, and abscisic acid. It enhances this resistance by strengthening cell walls, synthesizing defensive secondary metabolites, and regulating energy metabolism and stress responses. These findings provide a solid theoretical foundation for the future field application of B. velezensis in controlling walnut anthracnose. [ABSTRACT FROM AUTHOR]

Summary: Apple is an important cash crop in China, and it is susceptible to fungal infections that have deleterious effects on its yield. Apple bitter rot caused by Colletorichum gloeosporioides is one of the most severe fungal diseases of apple. Salicylic acid (SA) is a key signalling molecule in the plant disease resistance signalling pathways. Lignin synthesis also plays a key role in conferring disease resistance. However, few studies have clarified the relationship between the SA disease resistance signalling pathway and the lignin disease resistance pathway in apple. MdMYB46 has previously been shown to promote lignin accumulation in apple and enhance salt and osmotic stress tolerance. Here, we investigated the relationship between MdMYB46 and biological stress; we found that MdMYB46 overexpression enhances the resistance of apple to C. gloeosporioides. We also identified MdARF1, a transcription factor upstream of MdMYB46, via yeast library screening and determined that MdARF1 was regulated by miR7125 through psRNATarget prediction. This regulatory relationship was confirmed through LUC and qRT‐PCR experiments, demonstrating that miR7125 negatively regulates MdARF1. Analysis of the miR7125 promoter revealed that miR7125 responds to SA signals. The accumulation of SA level will result in the decrease of miR7125 expression level. In sum, the results of our study provide novel insights into the molecular mechanisms underlying the resistance of apple to C. gloeosporioides and reveal a new pathway that enhances lignin accumulation in apple in response to SA signals. These findings provide valuable information for future studies aimed at breeding apple for disease resistance. [ABSTRACT FROM AUTHOR]

Olive tree anthracnose is caused by infection with Colletotrichum fungi, which in Portugal are mostly C. nymphaeae, C. godetiae, and C. gloeosporioides s.s. Severe economic losses are caused by this disease that would benefit from a greener and more efficient alternative to the present agrochemical methods. Yeasts are serious candidates for pre-harvest/in field biocontrol of fungal infections. This work identified the yeast Wickerhamomyces anomalus as a strong antagonizer of the three fungi and studied in vitro this ability and its associated mechanisms. Antagonism was shown to not depend on the secretion of volatile compounds (VOCs), or siderophores or any other agar-diffusible compound, including hydrolytic enzymes. Rather, it occurred mostly in a cell-to-cell contact dependent manner. This was devised through detailed microscopic assessment of yeast-fungus cocultures. This showed that W. anomalus antagonism of the three Colletotrichum proceeded through (i) the adhesion of yeast cells to the phytopathogen hyphae, (ii) the secretion of a viscous extracellular matrix, and (iii) the emptying of the hyphae. Yeasts ultimately putatively feed on hyphal contents, which is supported by light microscopy observation of MB and PI co-culture-stained samples. Accordingly, numerous W. anomalus cells were observed packing inside C. godetiae emptied hyphae. This behaviour can be considered microbial predation and classified as necrotrophic mycoparasitism, more explicitly in the case of C. godetiae. The results support the prospect of future application of W. anomalus as a living biofungicide/BCA in the preharvest control of olive anthracnose. [ABSTRACT FROM AUTHOR]

One of the most important phytosanitary diseases affecting the production and marketing of the 'Hass' avocado fruit is anthracnose, mainly caused by the fungus Colletotrichum gloeosporioides. This disease is controlled with synthetic fungicides, which can cause harm to humans and the environment. Due to this, safer alternatives have been sought, such as biological control. The objective of this study was to isolate and characterize Bacillus spp. strains that biocontrol C. gloeosporioides in 'Hass' avocado fruits. The isolation, purification, and molecular identification of bacteria with biocontroller capacity was carried out. In vitro and in vivo tests were carried out against the pathogen C. gloeosporioides. Furthermore, the percentage inhibition of spore germination, enzymatic profile, and nutrient assimilation were determined. Forty-three native bacterial strains were isolated from the 'Hass' avocado fruit. The strains that showed the greatest antagonistic capacity in vivo against C. gloeosporioides were Bacillus pumilus AB31, B. thuringiensis AB30, B. thuringiensis AB7, and B. thuringiensis AB21. These strains could produce extracellular enzymes, such as phosphatases, proteases, and β-glucosidase, as well as the assimilation of D-ribose and trehalose. The above favors their antagonistic activity. Four strains of the genus Bacillus (one B. pumilus and three B. thuringiensis) can control C. gloeosporioides in 'Hass' avocado. [ABSTRACT FROM AUTHOR]

The microencapsulated yeast Meyerozyma guilliermondii LMA-Cp01 has previously shown high efficacy under laboratory tests against mango anthracnose caused by Colletotrichum gloeosporioides. Infection by C. gloeosporioides occurs in the field; therefore, it could be advantageous to apply the formulation at preharvest, which would reduce initial infection and control the pathogens. This work aimed to evaluate the effectiveness of free and two doses of microencapsulated M. guilliermondii applied in preharvest (four applications between early flowering and harvest) and one in postharvest to control mango anthracnose in two grown seasons. Besides, the effect of the treatments on quality parameters of mango fruit was also analyzed, as well as the quantification of the antagonist populations after its application on flowers and fruit. Preharvest applications of free and encapsulated M. guilliermondii significantly reduced anthracnose incidence and severity on fruit. M. guilliermondii microcapsules at 107 CFU mL−1 was as effective as fresh cells at 108 CFU mL−1. In orchard two, both doses of microcapsules were more effective than free cells and Captan, and no statistical differences between microcapsules and Benomyl were observed. The postharvest application was less effective in controlling mango anthracnose than preharvest. Under field conditions, LMA-Cp01 populations were higher on flowers and fruit treated with microencapsulated yeast than the free cells. Efficacy of M. guilliermondii was not improved by postharvest applications. Treatments did not adversely affect the quality parameters of mango. Microencapsulated M. guilliermondii LMA-Cp01 is a promising formulation to manage mango anthracnose through preharvest treatments. [ABSTRACT FROM AUTHOR]

Copyright of Nativa is the property of Revista Nativa and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: DIR (Dirigent) proteins play important roles in the biosynthesis of lignin and lignans and are involved in various processes such as plant growth, development, and stress responses. However, there is less information about VvDIR proteins in grapevine (Vitis vinifera L). Results: In this study, we used bioinformatics methods to identify members of the DIR gene family in grapevine and identified 18 VvDIR genes in grapevine. These genes were classified into 5 subfamilies based on phylogenetic analysis. In promoter analysis, various plant hormones, stress, and light-responsive cis-elements were detected. Expression profiling of all genes following Colletotrichum gloeosporioides infection and phytohormones (salicylic acid (SA) and jasmonic acid (JA)) application suggested significant upregulation of 17 and 6 VvDIR genes, respectively. Further, we overexpressed the VvDIR4 gene in Arabidopsis thaliana and grapes for functional analysis. Ectopic expression of VvDIR4 in A. thaliana and transient expression in grapes increased resistance against C. gloeosporioides and C. higginsianum, respectively. Phenotypic observations showed small disease lesions in transgenic plants. Further, the expression patterns of genes having presumed roles in SA and JA signaling pathways were also influenced. Lignin contents were measured before and after C. higginsianum infection; the transgenic A. thaliana lines showed higher lignin content than wild-type, and a significant increase was observed after C. higginsianum infection. Conclusions: Based on the findings, we surmise that VvDIR4 is involved in hormonal and lignin synthesis pathways which regulate resistance against anthracnose. Our study provides novel insights into the function of VvDIR genes and new candidate genes for grapevine disease resistance breeding programs. [ABSTRACT FROM AUTHOR]

Citrus diseases caused by fungal pathogens drastically decreased the yield and quality of citrus fruits, leading to huge economic losses. Given the threats of chemical pesticides on the environment and human health, biocontrol agents have received considerable attention worldwide as ecofriendly and sustainable alternative to chemical fungicides. In the present study, we isolated a Bacillus velezensis strain TZ01 with potent antagonistic effect against three citrus pathogenic fungi: Diaporthe citri, Colletotrichum gloeosporioides and Alternaria alternata. The culture supernatant of this strain exhibited remarkable antifungal activity on potato dextrose agar plates and detached leaves of five citrus varieties. Treatment with TZ01 culture supernatant obviously affected the hyphal morphology and caused nucleic acid leakage. The crude lipopeptides (LPs) extracted from the culture supernatant were found as the major active ingredients, and could maintain the activity under a wide range of temperature and pH and ultraviolet radiation. Furthermore, the type of LPs, produced in vitro, were explored. Whole-genome sequencing of TZ01 revealed secondary metabolite gene clusters encoding synthetases for non-ribosomal peptides and polyketide production, and gene clusters responsible for the synthesis of three important LPs (surfactin, iturin, and fengycin) were identified in the genome. The liquid chromatography-mass spectrometry analysis confirmed the presence of various homologs of surfactin A, bacillomycin D, and fengycin A in the extracted LPs. Taken together, these results contribute to the possible biocontrol mechanisms of B. velezensis strain TZ01, as well as providing a promising new candidate strain as a biological control agent for controlling citrus fungal pathogens. [ABSTRACT FROM AUTHOR]

Introduction: Camellia anthracnose is caused by multiple Colletotrichum species, resulting in severe yield losses of oil-tea Camellia. Colletotrichum fructicola is one of the major anthracnose pathogens of oil-tea Camellia worldwide. However, developing unique molecular markers for the rapid and accurate detection of Colletotrichum fructicola from diverse Colletotrichum species, as well as early monitoring and effective control of the disease, remains largely unexplored. Methods: C. fructicola-specific genes were obtained using a BLAST search of the sequences of predicted genes in C. fructicola against the genome sequences of Colletotrichum fungal pathogens. In this study, Colletotrichum fructicola- specific molecular markers were developed for rapid and accurate detection of C. fructicola among Camellia anthracnose causing fungal pathogens. Results: Using genomic DNA-based end-point PCR and qPCR, three C. fructicola-specific genes with the ability to distinguish C. fructicola from other oil-tea Camellia anthracnose-related Colletotrichum species, including Colletotrichum camelliae, Colletotrichum gloeosporioides, and Colletotrichum siamense, and oil-tea Camellia fungal pathogens belonging to the genus Neopestalotiopsis, Pestalotiopsis, and Alternaria, were validated as molecular markers. In addition, these three molecular markers were highly sensitive to detecting C. fructicola using DNA extracted fromthe inoculated leaves of oil-tea Camellia. Discussion: These findings enable us to rapidly and uniquely detect the Camellia anthracnose disease caused by Colletotrichum fructicola, which will equip farmers with an effective tool for monitoring Camellia anthracnose disease in the field and taking timely control measurements in advance. [ABSTRACT FROM AUTHOR]

Species of the genus Colletotrichum are among the most important plant pathogens globally, as they are capable of infecting many hosts—apple (Malus spp.) and other fruit and woody plant species—but also vegetable crops, cereals, legumes, and other annual and perennial herbaceous plants. The apple (Malus spp.) is attacked by various species from the genus Colletotrichum, whereby 27 different species from this genus have been described as the causative agents of apple bitter rot (ABR) and 15 as the cause of Glomerella leaf spot (GLS). These species generally belong to one of three species complexes: Colletotrichum acutatum, Colletotrichum gloeosporioides, and Colletotrichum boninense. The largest number of apple pathogens of the genus Colletotrichum belong to the species complex C. acutatum and C. gloeosporioides. However, further data on these species and the interactions between the species complexes of the genus Colletotrichum that cause these two apple diseases is needed for the development of effective control measures, thus ensuring successful and profitable apple cultivation. To contribute to this endeavor, a comprehensive review of the causative agents of ABR and GLS from the genus Colletotrichum is provided. In addition to presenting the species' current names, distribution, economic significance, and the symptoms they cause in apple, their development cycle, epidemiology, and molecular detection strategies are described, with a particular emphasis on control measures. [ABSTRACT FROM AUTHOR]

Plant endophytic microbial communities consist of many latent plant pathogens and, also, many pathogen-related species with reduced virulence. Though with a long history of co-evolution, the diversity and composition of the endophytic mycobiota, especially the pathogen-related fungal groups, has been under-investigated in Citrus (C.). Based on the amplicon sequencing of fungal internal transcribed spacer (ITS), the leaf endophytic mycobiota were profiled on citrus varieties from different citrus-producing regions. The pomelo variety shared significantly distinctive leaf mycobiota when compared to the mandarin and sweet orange; these conform to their host genetic relationships. In addition, a data set of 241 citrus-related fungi, including 171 (71%) pathogens and potential pathogens, was summarized from previous studies. Under the criteria of local BLAST (covered ITS nucleotide ≥ 150 bp, sequence identity ≥ 99%), a total of 935 fungal operational taxonomic units (OTUs) were assigned to 62 pathogen-related fungal groups, representing 14.9% of the relative abundance in the whole community. Of which, the top groups consisted of Colletotrichum gloeosporioides (mean relative abundance, 4.3%), Co. citricola and Co. karstii (2.7%), Zasmidium citri-griseum (2.4%), and Z. fructigenum (1.4%). At the genus level, the ratio of the pathogen-related fungal groups in 64% of fungal genera (16 out of 25) exceeded 50%, which are the solely or mainly occurring fungi of their genus in citrus. Our study suggests that the leaf endophytic compartment may be an important place for the growth of latent pathogens. [ABSTRACT FROM AUTHOR]

Colletotrichum gloeosporioides is the causal agent of poplar anthracnose, which induces major economic losses and adversely affects the ecosystem services of poplar forests. The appressorium serves as a penetration structure for many pathogenic fungi, including C. gloeosporioides. The production of mucilage and the formation of penetration pegs are critically important for the appressorium-mediated penetration of host tissues. We previously found that CgPmk1 is a key protein involved in appressorium formation, penetration, and pathogenicity. Although CgSte12, which is a transcription factor that functions downstream of CgPmk1, regulates the formation of penetration pegs, its role in C. gloeosporioides appressorium development and pathogenicity has not been elucidated. Here, we developed C. gloeosporioides CgSTE12 mutants and characterized the molecular and cellular functions of CgSTE12. The results showed that mycelial growth and morphology were not affected in the CgSTE12 knockout mutants, which produced normal melanized appressoria. However, these mutants had less mucilage secreted around the appressoria, impaired appressorial cone formation, and the inability to form penetration pores and pegs, which ultimately led to a significant loss of pathogenicity. Our comparative transcriptome analysis revealed that CgSte12 controls the expression of genes involved in appressorium development and function, including genes encoding cutinases, NADPH oxidase, spermine biosynthesis-related proteins, ceramide biosynthesis-related proteins, fatty acid metabolism-related proteins, and glycerophospholipid metabolism-related proteins. Overall, our findings indicate that CgSte12 is a critical regulator of appressorium development and affects C. gloeosporioides pathogenicity by modulating the structural integrity of appressoria. [ABSTRACT FROM AUTHOR]

Synthetic fungicides are used to control anthracnose caused by Colletotrichum gloeosporioides; however, their frequent application increases the risk of pathogen resistance, environmental damage, and health concerns. It has been reported that caprylic acid (CA) inhibits the in vitro development of C. gloeosporioides; however, its antifungal mechanism and in vivo antifungal potential are still unknown. Therefore, the present work aims to analyse the effect of a CA‐enriched sub‐fraction (CAES) extracted from Vitex mollis fruit on the fungal microstructure by confocal fluorescence microscopy and morphometric analysis. Moreover, the effect of CAES on anthracnose development and quality parameters in papaya fruit was evaluated. The confocal microscopy images confirmed that CAES damaged the cell wall of conidia, given their decreased width. The increased fluorescence intensity in the CAES and CA‐treated mycelium suggested they were attached to the plasma membrane. These treatments produced structural alterations of the vacuoles and septa in mycelium, while in the fungicide thiabendazole (TBZ) treatment, apoptotic bodies appeared. CAES at 1.0 g L−1 had the best effect against anthracnose incidence and severity in papaya fruit, whereas TBZ was only effective on anthracnose severity. None of the applied treatments affected the fruit quality parameters. Therefore, CAES may be develop as an effective option to suppress anthracnose on papaya fruit. [ABSTRACT FROM AUTHOR]

Summary: Food pathogens are one of the microbiological problems that have negative effects on both economic and human health by causing spoilage and decay of important foods such as fruits and vegetables. The adverse effects of chemical residues left by synthetic biocides on human health and the development of resistance mechanisms in microorganisms have directed research towards bio‐fungicide. This study aimed to develop an effective bio‐fungicide using varying concentrations of ethyl pyruvate (1–18 μL disc−1). Additionally, the interaction of EP with several proteins in pathogenic bacteria and fungi was investigated through in silico molecular docking. According to the obtained results, an increase in EP concentration resulted in larger inhibition zone diameters. In this context, at an EP concentration of 18 μL disc−1, the inhibition zones formed against E. coli, S. aureus, L. monocytogenes and S. typhimurium bacteria were measured as 27.50 ± 0.50 mm, 31.00 ± 1.00 mm, 30.00 ± 1.00 mm and 32.66 ± 1.15 mm, respectively. EP at a concentration of 9 μL disc−1 showed a fungicidal effect against B. cinerea and P. expansum and a fungistatic effect against C. gloeosporioides. As a result of in silico tests, the molecular binding energies of EP with E. coli dihydrofolate reductase, S. aureus DNA Gyrase B and B. cinerea 14 alpha‐demethylase were determined to be −4.62, −4.26 and −3.95 kcal mol−1, respectively. Our results holistically revealed that EP has great potential for use in food preservation due to its antifungal and antibacterial properties. [ABSTRACT FROM AUTHOR]

Crop disease often leads to field epidemics with serious threats to yield. Early symptoms are sometimes difficult to identify, so the origin of primary inoculum is a critical focal point in the study of plant diseases, as it can help design management strategies to reduce crop losses. Here, we investigated whether anthracnose of water yams (Dioscorea alata L.) caused by the species complex Colletotrichum gloeosporioides can start from infected seed tubers from the previous harvest. Over two years, we collected tubers with varying pathogen prevalence in the field directly from producers and conducted fungal isolations in the lab to sample C. gloeosporioides. We also proceeded to artificially inoculate tubers before planting and monitored disease development. Finally, we genotyped isolates from leaves in the fields and assessed fixation indices between plots based on plot ownership (plots with a common seed tuber origin from a single farmer) vs. samples in plots from unrelated producers in Guadeloupe, Martinique, and Barbados. We were unable to isolate the fungus from harvested tubers in either sampling survey nor did any plants grown from inoculated tubers develop any disease symptoms during growth. Also, the genetic structure of samples within each plot was independent of plot ownership, though this occurred with varying levels in the different islands. These results suggest that contaminated planting material from seed tubers is not the primary source of the disease, which is in contrast to the common perception of yam anthracnose prevalence in the Antilles. [ABSTRACT FROM AUTHOR]

• Citrus anthracnose in Indonesia caused by C. gloeosporioides species complex. • Colletotrichum spp. multigene analysis based on Actin, β-tubulin, and GAPDH genes. • C. gloeosporioides , C. endophytichum , C. queenslandicum caused citrus anthracnose. • First report of C. endophytichum , C. queenslandicum in Indonesia. Citrus (Citrus spp.), including orange as an important one, has a high economic value and significant role both in global market as well as in Indonesia. However, citrus anthracnose caused by Colletotrichum spp. constantly becomes a limiting factor in citrus production. Nevertheless, there is no report on molecular basis about the species associates to the citrus anthracnose in Indonesia up to date. Therefore, this research aims to identify the isolates of Colletotrichum spp. based on polyphasic approach which combining morphological character, pathogenicity and multigene analysis using actin, β-tubulin, and GAPDH primers. Twenty-two isolates were obtained from leaves and citrus fruits with anthracnose symptoms which showed various morphological characteristics, both macroscopic and microscopic. Pathogenicity test results showed that all 22 isolates were virulent to Keprok Batu 55 orange and California lemon. The anthracnose symptoms produced are identical to the symptoms in the field, however the symptoms on the California lemon were milder than on the Keprok Batu 55 mandarin. The results of multigene analysis showed that there were three species causing citrus anthracnose in Indonesia, which were C. endophytichum , C. queenslandicum , and C. gloeosporioides. Those three species are C. gloeosporioides species complex, and this is the first report of C. endophytichum , C. queenslandicum causing citrus anthracnose in Indonesia which needs further concern for biosecurity. All isolate sequences based on actin, β-tubulin, and GAPDH gene markers were submitted into the GenBank and got accession numbers of OR188855–OR188875. [ABSTRACT FROM AUTHOR]

Melons (Citrullus lanatus (Thumb) Mansf. and Leganaria siceraria (Mol.) Standley) are vital vegetable crops in West Africa, valued for their edible nutrient-rich seeds and oil. However, their production is impacted by leaf blight, while the economic yield loss caused by this disease is not well documented. This study examined the effects of three blight-causing pathogens: Colletotrichum truncatum (Ct), Colletotrichum gloeosporioides (Cg), and Lasiodiplodia theobromae (Lt) on the growth and yield traits of melon. Three melon cultivars (Bara, Serewe, and Bojuri) were artificially inoculated with these pathogens in two field trials using a randomized complete block design with four replicates. Data on growth and yield parameters (GYPs) were analyzed using analysis of variance (p<0.05). The pathogens significantly affected GYPs depending on the cultivar. In Serewe cultivar, Lt significantly reduced vine length (from 82.9 to 28.2 cm) and the number of leaves (from 74.3 to 39.2). In Bara, the three pathogens reduced the number of leaves and number of vines, while a significant reduction of vine length was caused by Ct (from 98.2±9.9 to 42.4±7.7cm) and Lt (98.2±9.9 to 41.5±13.6cm). However, the GYPs of Bojuri was unaffected by the three blight pathogens. The pathogens also reduced the number of fruits per/plant of Serewe cultivar (from 7.8±2.6 to 3.1±0.6) and weight of fruits/per plant (from 8.0±5.0 to 1.6±0.9 kg) and all the evaluated yield parameters in Bara except weight of fruits/plant which was only reduced by Ct (from 3.1±0.8 to 1.2±0.8 kg). Lasiodiplodia theobromae (95.7%) and Ct (92.9%) caused the highest reduction observed in the weight of seeds/plant of Serewe and Bara, respectively. This study highlights significant yield losses due to Colletotrichum and Lasiodiplodia species in Serewe and Bara melon cultivars, emphasizing the need for effective disease management strategies. [ABSTRACT FROM AUTHOR]

Copyright of Universitas Scientiarum is the property of Pontificia Universidad Javeriana and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Colletotrichum spp. is a phytopathogen causing anthracnose in a variety of tropical fruits. Strategies used to control postharvest diseases in tropical fruits typically rely on the use of synthetic fungicides, which have stimulated the emergence of resistant pathogens. Safer alternative strategies to control anthracnose in tropical fruits have been described in the literature. This review presents and discusses the main innovative interventions concerning the application of sustainable alternative strategies in the postharvest control of pathogenic Colletotrichum species in tropical fruits, with a particular emphasis on the studies published in the last 5 years. The available studies have shown the use of various methods, including physical barriers, natural antimicrobials, and biological control with antagonistic microorganisms, to reduce anthracnose lesion severity and incidence in tropical fruits. The available literature showed high inhibitory activity in vitro, reduced anthracnose incidence and lesion diameter, and total disease inhibition in tropical fruits. Most studies focused on the inhibition of Colletotrichum gloeosporioides on avocado, papaya, and mango, as well as of Colletotrichum musae on banana; however, the inhibition of other Colletotrichum species was also demonstrated. The application of emerging sustainable alternative methods, including natural antimicrobial substances, also stimulated the induction of defense systems in tropical fruits, including enzymatic activity, such as polyphenol oxidase, peroxidase, and phenylalanine ammonia‐lyase. The retrieved data helped to understand the current state of the research field and reveal new perspectives on developing efficient and sustainable intervention strategies to control pathogenic Colletotrichum species and anthracnose development in tropical fruits. [ABSTRACT FROM AUTHOR]

Camellia oleifera C. Abel is a woody oil crop with multiple purposes. This study aims to investigate the mutagenic effects of 60Co-γ radiation on C. oleifera seedlings and to screen anthracnose-resistant mutants. Two C. oleifera varieties were investigated: 'Xianglin 1' (XL1) and 'Xianglin 210' (XL210). Seeds were irradiated with 0 Gy, 30 Gy, 50 Gy, and 80 Gy of 60Co-γ, and after one year of planting, the mutagenic lines were studied, and disease-resistant mutants were screened. Results showed that as the radiation intensity was increased, the emergence percentage of both C. oleifera XL210 and XL1 was significantly decreased. Radiation significantly changed the SOD and POD activities in both varieties. Furthermore, 80 Gy irradiated lines showed reduced anthracnose resistance in both varieties. However, 50 Gy irradiated lines showed enhanced disease resistance in XL210 while reducing it in XL1. The 30 Gy irradiated lines did not affect the disease resistance of either variety. Colletotrichum gloeosporioides infection tests were conducted on 94 mutant C. oleifera seedlings, resulting in 8 highly resistant mutants (A3, A8, A10, A19, A21, A32, A35, B17) and 3 susceptible mutants (A4, B15, B27) in XL210 and XL1. Differences in SOD and POD activities led to variations in disease resistance among different mutants. Additionally, the expression levels of CoSOD1, CoPOD, CoIDD4, and CoWKRY78 were varied among the different mutants. This study delivers the screening of disease-resistant mutants in C. oleifera through mutagenic breeding, providing material for the development of new C. oleifera varieties and serving as a resource for further research in mutagenic breeding. [ABSTRACT FROM AUTHOR]