Lasiodiplodia Theobromae Research Articles

The Therapeutic Potential of Agarwood as an Antimicrobial and Anti-Inflammatory Agent: A Scoping Review

Background/Objectives: Microorganisms such as bacteria, viruses, and fungi are frequently the cause of infections. Antimicrobial agents, such as antibiotics, antivirals, and antifungals, are used to target and eliminate these infectious agents. On the other hand, inflammation is a natural response of the immune system to injury, infection, or irritation. Although herbal remedies have been used to treat these conditions for centuries and can be effective in certain situations, it is crucial to use them with caution. Not all herbal remedies are supported by scientific evidence, and their safety and efficacy can vary. Thus, we conducted this review to determine the potential health benefits of agarwood as an antimicrobial and anti-inflammatory agent. Methods: Three databases (PubMed, Scopus, and Google Scholar) were used to search for original papers submitted between 2013 and 2023, using the Medical Subject Heading (MeSH) terms “agar-wood” crossed with the terms “antimicrobial” and/or “anti-inflammatory”. Synonyms and relevant search terms were also searched. Results: The most-studied agarwood for antimicrobial and anti-inflammatory agents is Aquilaria sinensis. Some studies have shown its potential application as a potent inhibitor of fungi, including Lasiodiplodia theobromae, Fusarium oxysporum, and Candida albicans. Moreover, it is capable of inhibiting Bacillus subtilis and Staphylococcus aureus activities. Several chromones detected in agarwood have been shown to inhibit NF-κB activation, LPS-induced NO production, and superoxide anion generation. In conclusion, more research is needed, particularly regarding future intervention studies, to enhance our knowledge and understanding of agarwood and its isolates. Conclusions: This review reveals that despite the absence of clinical trials, agarwood exhibits antimicrobial and anti-inflammatory properties.

Isolation and Identification of Pathogenic Microorganisms Causing Post‐Harvest Disease of Garlic (Allium sativum L.) in Ninh Thuan Province, Vietnam

ABSTRACTGarlic plays a crucial role in Vietnam's agricultural economy. However, the presence of post‐harvest diseases presents considerable obstacles as it reduces the quality and market value of the crop. The objective of this study was to identify the microbial strains responsible for these diseases through isolation and identification. A comprehensive analysis was conducted to identify six pathogenic species that have a significant impact on the quality of post‐harvest garlic in Phan Rang, Ninh Thuan province, Vietnam. This analysis involved morphological observations, microscopic assessments, pathogenicity testing and molecular sequencing. Fusarium solani, F. oxysporum and Lasiodiplodia theobromae were identified as the main causes of dry rot, while Macrophomina phaseolina was associated with charcoal rot. Moreover, Aspergillus niger has been associated with black mould, while Pantoea sp. has been identified as the causative agent of soft rot. Re‐infection tests following Koch's postulates conducted on garlic bulbs provided confirmation of the isolates' pathogenicity. These findings have significant implications for enhancing our understanding of garlic diseases after harvest, which can contribute to the development of effective control measures in the future.

Botryosphaeriaceae Infections on Prunus Germplasm: Evaluation of Pathogenicity, Resistance Loci, and Detached Assays of Southeastern United States Isolates

Research of peach fungal gummosis (PFG), which is a vascular disease caused by fungi in the Botryosphaeriaceae family, is particularly important in the southeastern United States, southern China, South Africa, and Western Australia. This disease has been a significant concern for the peach industry in the southeastern United States since the 1970s. The changing climatic conditions in the prunus production areas of the world have worsened the severity of PFG disease. A study of the morphological and genetic profiles of Botryosphaeriaceae species from diseased peach trees found four species in Georgia, Florida, Alabama, and South Carolina. Botryosphaeria dothidea, Lasiodiplodia theobromae, Diplodia seriata, and Neofusicocoum parvum were isolated and identified using conidiospore characters and rDNA sequences of internal transcribed spacer regions and elongation factor α-1 genes. B. dothidea was the most common species from diseased peach trees. A significant implication of this research is the potential resistance in Prunus germplasm, which was genotyped for the resistance locus Botd8 and evaluated for relative susceptibility to one isolate each from B. dothidea, L. theobromae, and D. seriata. Pathogenicity evaluations of peach, almond, and interspecific hybrids used detached stem and leaf assays for susceptibility to PFG based on lesion lengths and gumming scores. L. theobromae inoculation resulted in the most extensive lesions on stems and leaves. Detached stem and leaf assays indicated that Prunus with the Botd8 locus significantly differed in lesion size when infected with B. dothidea and D. seriata. However, the resistant locus had no significant effect on the relative susceptibility of Prunus to L. theobromae. Field and detached stem and leaf assays identified almond cultivars Pioneer and Golden State and Peach × Almond hybrids with Botd8 (+) as tolerant to PFG. Correlations between detached assays and field gumming scores suggested that inoculations on detached stems or leaves under controlled conditions can be used to preliminarily screen for resistance to PFG. These detached assays for specific pathogen isolates provide an opportunity for a relatively fast, nondestructive evaluation of Prunus germplasm and are tools that can be used to identify the components of disease resistance.

Bioherbicidal effect of secondary metabolites from Lasiodiplodia theobromae for management of narrow-leaf and broad-leaf weeds

Herbicides are the most used form of weed management worldwide but their excessive use could lead to negative impacts on human health and the environment. Biological weed management utilizing microorganisms and their metabolites presents a promising alternative. The weed-associated fungus Lasiodiplodia theobromae TBRC 15112 produces a broad spectrum of biological molecules, and shows potential as a bioherbicide. In this study, L. theobromae crude extracts from cultures caused leaf lesions in crowfoot grass (Dactyloctenium aegyptium L.) and tridax daisy (Tridax procumbens L.). The treated tridax daisy plants wilted and collapsed in three days. Using HP-20SS column chromatography, the 20, 30 and 40% acetone fractions caused leaf lesions covering 54, 30 and 34% of whole leaf areas of D. aegyptium, respectively, whereas relatively lower severities were observed for the 50–70% fractions. Eight compounds, including one new metabolite, were isolated and characterized for their structures using NMR spectroscopic data. Of these, five exhibited bioherbicidal activity, namely uracil, tyrosol, N-(4-hydroxyphenyl) acetic acid, N-(4-hydroxyphenyl) acetamide (4HPA), and the new metabolite. This metabolite, which we named lasiodiplin, is similar to alboatrin but distinct at two positions. Intriguingly, the mixture of tyrosol and 4HPA had a greater effect on weed leaves than pure compounds alone, suggesting a synergistic effect. The crude extracts also caused leaf lesions on five of six tested crops. Our study revealed that L. theobromae crude extracts have bioherbicidal activity on the narrow-leaf and broad-leaf weeds. The data could pave a way for further development of bioherbicides based on microorganisms and microbial products.

Pathological Characterization and Management of Lasiodiplodia theobromae, a Hemibiotroph with an Interkingdom Host Range.

Heart rot disease, caused by Lasiodiplodia theobromae, is destructive for date palms and other woody plants. The disease was reported in several oases in Egypt, and the pathogen was found in association with infected trees suffering dieback and rachis blight. Seven phylogenetically distinct fungal isolates were selected, and their pathogenicity was confirmed on date palms. The isolates exhibited variable degrees of virulence on inoculated leaves, which confirms the variation. We examined the antifungal effect of microbial bioagents and plant extracts on heart rot disease. The isolates of Trichoderma spp. gave moderate reduction of the pathogen's linear growth (40 to 60%), whereas their exudates were ultimately ineffective. Bacillus spp. isolates, except for B. megaterium, were more effective against spore germination, giving 80 to 90% reduction on average. Among the examined plant extracts, garlic sap gave 98.67% reduction of linear growth followed by artemisia (15.5%) and camphor (24.8%). The extraction methods greatly influenced the antifungal efficiency of each extract because exposure to organic solvents significantly decreased the efficiency of all extracts, whereas hot water extraction negatively affected garlic sap only. Successful bioagents and plant extracts were further assayed for the suppression of heart rot disease on date palms. Both T. album and T. harzianum gave comparable degrees of suppression as by commercial fungicides. In addition, treatment before or during pathogen inoculation was the most effective because it significantly enhanced the expression of defense-related enzymes. Our findings suggest biopesticides possess a dual role in disease suppression and defense boosters for date palms suffering heart rot disease.

Efficacy of antibiotics and bactericides against Xanthomonas axonopodis pv. citri causing bacterial canker disease of acid lime (Citrus aurantifolia)

Diseases are the major constraints for citrus production which impede the fruit yield and quality. Citrus suffers from a number of diseases caused by fungi, bacteria, viruses and viriods. Among these diseases, canker caused by Xanthomonas axonopodis pv. citri, foot rot or gummosis caused by Phytophthora spp., twig blight caused by Diplodia natalensis and Fusarium spp. Three antibiotics and three bactericides viz., Streptocycline, Kasugamycin 5% + Copper oxychloride 45% WP, Kasugamycin, Bacterimycin, Copper oxychloride 50% WP, Copper hydroxide 53.8% W/W were evaluated for their effectiveness in controlling the growth of Xanthomonas axonopodis pv. citri at the Department of Plant Pathology, College of Agriculture, Ummendganj-Kota, (Agricultural University, Kota) Rajasthan. Inhibition was highest in case of copper oxychloride 50% WP (34.20 mm) followed by bronopol 27% (28.90 mm) and streptocycline 90% W/W (12.48 mm) at 500 ppm concentration and no inhibition zone was found in kasugamycin. All the antibiotics/bactericides inhibited bacterial growth at higher concentrations.

<i>In vitro</i> studies on the development of microbial consortia for the management of major diseases in coconut and citrus

Microbial consortia for disease suppression involve combining multiple beneficial microorganisms to enhance their effectiveness in plant disease management. In present study, development of microbial consortia for the management of major diseases in coconut and citrus was carried out using bacteria Pseudomonas fluorescens, Pseudomonas putida (striata), Bacillus subtilis and fungi – Trichoderma reesei, T. harzianum, T. asperellum against major pathogens viz. Ganoderma lucidum, Thielaviopsis paradoxa, Phytopthora palmivora, Lasiodiplodia theobromae isolated from the coconut rhizosphere, and Fusarium solani isolated from the citrus rhizosphere. The promising fungal and bacterial antagonists were identified and studied for compatibility. Non-volatile compounds of consortia inhibited the test pathogens with an increase in concentration from 10 % to 75% with fungal consortia and bacterial consortia and also with mixed consortia which is composed of bacterial consortia + fungal consortia. Superior growth suppression was recorded with mixed consortia even at 10% concentration (59.44% to 65.83%) against the test pathogens in the ascending order of L. theobromae (59.44%) T. paradoxa (63.89%), G. lucidum (65.83%), P. palmivora (63.61%) and F. solani (62.78%). A similar trend was observed in 75% concentration where inhibition observed in the order of Thielaviopsis paradoxa (90.28%), G. lucidum (89.44%), F. solani (82.50%), L. theobromae (81.94%) and P. palmivora (81.39%). Volatile effect by bacterial consortia recorded the superior inhibition on test pathogens in the order of Ganoderma (85.28%), F. solani (75.28%), T. paradoxa (71.94%), P. palmivora (71.67%) and L. theobrome (67.50%) compared to the individual bioagents. Similarly, the fungal consortia showed the superior inhibitory effect on test pathogens in the order of G. lucidum (83.25%), P. palmivora (82.50%), L. theobromae (83.06%), F. solani (80.56%) and T. paradoxa (73.61%). Since there was no zone of inhibition between the strains, the interactions between Pseudomonas and Bacillus strains of Trichoderma spp. were compatible with one another. Neem cake recorded superior CFU population from 9.43 X 106 CFU at seven days by T. asperellum. Shelf life study on mixed consortia with bacterial + fungal bioagents in talc formulation indicated that all the bacterial and fungal CFU count recorded in 106 dilution for 90 days.

Pyriofenone Interacts with the Major Facilitator Superfamily Transporter of Phytopathogenic Fungi to Potentially Control Tea Leaf Spot Caused by Lasiodiplodia theobromae.

Tea leaf spot caused by Lasiodiplodia theobromae is a newly discovered fungal disease in southwest China. Due to a lack of knowledge of its epidemiology and control strategies, the disease has a marked impact on tea yield and quality. Pyriofenone is a new fungicide belonging to the aryl phenyl ketone fungicide group, which has shown marked efficacy in controlling various fungal diseases. However, its mechanism of action is not yet understood. This study found that pyriofenone exhibits strong in vitro inhibitory activity against various phytopathogenic fungi. Specifically, it showed strong inhibitory activity against L. theobromae, with a half-maximal effective concentration (EC50) value of 0.428 μg/ml determined by measuring mycelial growth rate. Morphological observations, using optical, scanning electron, and transmission electron microscopy, revealed that pyriofenone induces morphological abnormalities in L. theobromae hyphae. At lower doses, the hyphae became swollen, the distance between septa decreased, and the hyphal growth rate slowed. At higher doses and longer exposures, the hyphae collapsed. Transcriptomic and bioinformatic analyses indicated that pyriofenone can affect the expression of genes related to membrane transporters. Homology modeling suggested that pyriofenone may bind to a candidate target protein of the major facilitator superfamily (MFS) transporter, with a free binding energy of -7.1 kcal/mol. This study suggests that pyriofenone may potentially regulate the transport of metabolites in L. theobromae, thus affecting hyphal metabolism and interfering with hyphal growth. Pyriofenone exhibits in vitro inhibitory activity against various tea foliar pathogens and holds promise for future applications to the control of tea foliar diseases.

Lasiodiplodia theobromae keratitis – A rare case mimicking Pythium keratitis

A 61-year-old male presented with a corneal ulcer in the right eye and gave a history of trauma with cow-tail 5 days back. The best corrected visual acuity was finger counting at 1 meter, less than n -36 in the right eye. Potassium hydroxide mount revealed broad aseptate filaments. On suspicion of Pythium keratitis, hourly linezolid eyedrop was started but no improvement was seen. The culture grew Lasiodiplodia theobromae, and the ulcer started healing within 2 weeks of starting natamycin 5% eyedrop. This case report highlights the similarities of filaments of Lasiodiplodia and Pythium species on microscopic examination of corneal scraping.

Isolation and identification of fungi causing post-harvest spoiled mango fruits vended in Hanoi, Vietnam

Mango (Mangifera indica L.) is one of the most popular and nutritious fruits cultivated widely in Vietnam. However, under increasingly harsh climate conditions, mangoes are easily susceptible to fungal invasion and spoiled, thereby reducing mango yield. Therefore, this study was carried out to determine the pathogenic fungal strains of mango to provide useful information for finding effective measures to prevent the diseases. Rotten mango fruits were collected from different markets in Hanoi, Vietnam. Three fungal strains (M1, M2 and M3) were isolated from the studied mangoes samples. All strains were demonstrated as fungal agents associated with mango rot through pathogenicity tests. Microscopic observation showed that the mycelium of these fungal strains was branched and septate. M1 strain formed dark-brown conidiophores and conidia produced on conidiophores. M2 strain produced α- and β-conidia, as well as sub-ovoid and brown sclerotia. Whereas the M3 strain could not produce spores. Additionally, this study determined that all three fungal isolates showed the fastest growth on PDA at 30oC. The optimum growth of the M1 and M3 strains was observed at pH 5.0 while the M2 strain grew actively at pH 7.0 and 8.0. All selected strains showed the ability to produce extracellular enzymes, in which the M1 strain synthesized both cellulase and pectinase while the M2 and M3 strain secreted only pectinase. Finally, by molecular identification method, the isolates (M1, M2 and M3) were identified as Aspergillus niger isolate M1, Phomopsis sp. M2, Lasiodiplodia theobromae M3, respectively.

In vitro evaluation of fungicides against eucalyptus stem canker pathogens in Ethiopia

Field surveys of Eucalyptus camaldulensis diseases were conducted during 2019-20 and 2020-21 in Ethiopia. This species was the most commonly planted in the surveyed fields and exhibited stem canker diseases. Sampling was performed from diseased stems and branches displaying clear symptoms. Morphological and PCR assays of the ITS1 and ITS2 loci were conducted to identify the fungal pathogens. Lasiodiplodia theobromae and Didymella pinodella were identified as the fungal pathogens causing E. camaldulensis stem canker diseases. Four nationally licensed fungicides viz. Vitra (copper hydroxide), Ridomil Gold (metalaxyl-M + mancozeb), Liveshow (pyraclostrobin + epoxiconazole), and Sabozeb (mancozeb) were evaluated for their in vitro control efficacy against the identified fungi at different concentrations (500, 1000, 1500, and 2000 ppm). Vitra and Liveshow were found to be the most effective fungicides at 2000 ppm for the control and treatment of E. camaldulensis stem canker diseases. The identification of L. theobromae and D. pinodella as causal agents of E. camaldulensis is crucial for targeted disease management strategies. The evaluation of four fungicides at different concentrations provided valuable information for selecting the most effective treatment options for practical management practices of the diseases. This research serves as the first report on the management of Eucalyptus disease in Ethiopia, laying the foundation for future studies and contributing to the development of sustainable disease management practices. The findings of this research can guide policymakers, researchers, and agricultural practitioners in implementing targeted fungicide applications to mitigate the impact of stem canker on Eucalyptus plantations and improve their productivity.

First Report of Leaf Blight of Blood Lily (Scadoxus multiflorus) Caused by Lasiodiplodia theobromae in India

ABSTRACTLeaf blight was detected on potted blood lily (Scadoxus multiflorus) plants in a garden located in Andhra Pradesh, India. Pycnidia resembling a Lasiodiplodia species were consistently detected on the foliage of symptomatic plants. Based on morphology, cultural features and molecular analysis, the species was identified as Lasiodiplodia theobromae. Koch's postulates were fulfilled by pathogenicity tests carried out on potted blood lily plants. To the best of our knowledge, this is the first report of the occurrence of a disease caused by L. theobromae on S. multiflorus.

First Report of Lasiodiplodia theobromae Causing Fruit Crown Rot on Banana in Ecuador.

Post-harvest diseases like fruit crown rot (CR) on bananas (Musa spp.) worldwide are mainly attributed to Colletotrichum gloeosporioides (Berk. & Curt.) von Arx and Lasiodiplodia theobromae (Pat.) Griff. & Maubl (Sangeetha et al., 2012; Riera et al., 2019). In April 2019, at a banana farm (cultivar Williams) located in El Oro province (location at 79° 54' 05" W; 03° 17' 16" S), thirty hands were randomly collected from the postharvest process and further placed in a humid chamber at 20 ºC until signs of the disease progressed and became more evident (from 3 days to 20 days). Ten hands presented initial symptoms related to CR during the postharvest process, which included crown or peduncle rot with mycelial development on the crown's surface, leading to the blackening of tissues at the site of the wound left when the cluster was cut. Crown fruit fragments (~0.5 cm) from the edge of healthy tissue and diseased tissue underwent a series of disinfection steps, initially in ethanol (70%) for 1 min, followed by sodium hypochlorite (1%) for 1 min, rinsed three times with sterile distilled water, and dried on sterile filter paper for 10 min. The fragments were placed onto Potato dextrose agar (PDA) + chloramphenicol (100 mg L-1) and incubated at 25°C in darkness for five days. Five isolates with different colony morphologies were obtained. An initial screen of the pathogenicity of all isolates showed that only one isolate showed disease activity in banana crowns. This isolate, C1, showed grayish-white aerial mycelium in culture as described above and, after ten days, became black. We did a full pathogenicity test with C1 using ten individual banana fruits (cv. Williams Cavendish). Briefly, one disc (Ø of 5 mm) of the fungus with agar was placed on the acropetal part of the banana fruit (on the peel) and another piece in the crown without wounding. Inoculated fruit were in a humid chamber at 20 °C for 20 days. Uninoculated fruits constituted the control. Isolate C1 caused 100% of the fruit and crowns to rot, with symptoms similar to those initially observed from fruit collected at the postharvest process (Fig. S1d). The fungus was re-isolated from symptomatic tissue, and its identity was confirmed through morphological characteristics consistent with Lasiodiplodia sp. Matured conidia of all mono hyphal strains (Fig. S1b) appeared dark brown with a single septum, having an ovate shape, and displayed longitudinal striations along their thickened walls (Fig. S1c). The dimensions of the mature conidia ranged from 16.02 - 26.85 x 11.09 - 16.74 µm (n = 60). Morphological characteristics showed similarity to Lasiodiplodia sp. (Alves et al., 2008). Microscopic observations were further confirmed by sequencing three loci: the internal transcribed spacer (ITS), β-tubulin, and partial translation elongation factor-1α (TEF-1α). Fungal genomic DNA from the C1 isolate was PCR amplified using ITS5/ITS4, EF1-728F/986R, and Bt2A/Bt2B primers, respectively, according to Glass & Donaldson (1995) and Bautista-Cruz et al. (2019). The resulting amplicons were sequenced, and those sequences were deposited in GenBank with the accession numbers ITS: PP532861, TEF-1α: PP551938, and β-tubulin: PP537587. Sequence alignment was conducted using ClustalW under the MEGA 11.0 software package (Tamura et al., 2021). Subsequently, phylogenetic analysis was performed using Bayesian inference using the BEAST v1.8.4 program (Drummond & Rambaut, 2007). The concatenated sequence of the isolate revealed clustering to the Lasiodiplodia theobromae clade, confirming its identity. To our knowledge, this is the first report of this pathogen causing CR on banana fruit in Ecuador. Based on the report of CR in the country, banana exporters and the Ecuadorian government should consider developing disease management methods that include the cultivation, shipping, ripening, and storage processes of the fruit.

Two monoacyl glycerols isolated from B. mycoides, B. weihenstephanensis and B. toyonensis and their antifungal activity against Lasiodiplodia theobromae, pathogen of cacao

In this work two known monoacyl glycerols, glycerol 1-monopalmitate and glycerol 1-monostearate, were isolated for the first time from B. mycoides, B. weihenstephanensis and B. toyonensis. These monoacyl glycerol compounds showed good antifungal activity specially, against Lasiodiplodia theobromae, which is the fungus affecting cacao. A study of the cell damage done by these monoacyl glycerols was performed in three phytopathogens, resulting in severe damage of reproductive structures, indicating for the first time the potent antifungal activity of these compounds. It could be a promising result to apply in agriculture crops. This work contributes with the research about Bacillus species secreting metabolites, since this is the first time that is reported about the mono acyl glycerols as compounds secreted by Bacillus species. Furthermore, this work explores the role that Bacillus genus can play in controlling important fungi in agriculturally important crops such as cacao.

Diplodia seriata Isolated from Declining Olive Trees in Salento (Apulia, Italy): Pathogenicity Trials Give a Glimpse That It Is More Virulent to Drought-Stressed Olive Trees and in a Warmth-Conditioned Environment.

The fungi Botryosphaeriaceae are involved in olive declines in both the world hemispheres and in all continents where this species is cultivated. In Salento (Apulia, Italy), the Botryosphaeriaceae Neofusicoccum mediterraneum and N. stellenboschiana have been reported as the agents of a branch and twig dieback that overlaps with olive quick decline syndrome caused by Xylella fastidiosa subsp. pauca. In this study, we report the finding of Diplodia seriata, another Botryosphaeriaceae species, in Salento in Xylella fastidiosa-infected olive trees affected by symptoms of branch and twig dieback. Given that its presence was also reported in olive in the Americas and in Europe (Croatia) with different degrees of virulence, we were prompted to assess its role in the Apulian decline. We identified representative isolates based on morphological features and a multilocus phylogeny. In vitro tests showed that the optimum growth temperature of the isolates is around 25-30 °C, and that they are highly thermo-tolerant. In pathogenicity trials conducted over eleven months, D. seriata expressed a very low virulence. Nonetheless, when we imposed severe water stress before the inoculation, D. seriata significatively necrotized bark and wood in a time frame of 35 days. Moreover, the symptoms which resulted were much more severe in the trial performed in summer compared with that in autumn. In osmolyte-supplemented media with a water potential from -1 to -3 Mpa, the isolates increased or maintained their growth rate compared with non-supplemented media, and they also grew, albeit to a lesser extent, on media with a water potential as low as -7 Mpa. This suggests that olives with a low water potential, namely those subjected to drought, may offer a suitable environment for the fungus' development. The analysis of the meteorological parameters, temperatures and rainfall, in Salento in the timeframe 1989-2023, showed that this area is subjected to a progressive increase of temperature and drought during the summer. Thus, overall, D. seriata has to be considered a contributor to the manifestation of branch and twig dieback of olive in Salento. Coherently with the spiral decline concept of trees, our results suggest that heat and drought act as predisposing/inciting factors facilitating D. seriata as a contributor. The fact that several adverse factors, biotic and abiotic, are simultaneously burdening olive trees in Salento offers a cue to discuss the possible complex nature of the olive decline in Salento.

Favorable outcome of Lasiodiplodia theobromae keratomycosis : a clinical case and systematic review

BackroudKeratitis caused by Lasiodiplodia theobromae is rare and typically associated with a poor prognosis. Current literature lacks sufficient evidence on effective management of patients with this condition.Case presentationA 74-year-old former agricultural worker presented with a red right eye, discomfort, and decreased visual acuity, progressing over three days without treatment. Examination revealed type 2 diabetes and a non-perforating, spiculated corneal abscess with a hypopyon in the right eye. Initial treatment included a triple antibiotic therapy and supportive care. Direct mycological examination identified numerous septate mycelial filaments. Antifungal treatment with natamycin and voriconazole, both topically and orally, was initiated. Cultures confirmed Lasiodiplodia theobromae. The patient showed significant improvement. Treatment continued for eight weeks, with a final visual acuity of 20/50 due to a stromal scar.ConclusionAn extensive literature review conducted in November 2023, using databases such as PubMed and Google Scholar with the keywords “lasiodiplodia” and “keratitis” yielded no previous cases of this specific condition being managed solely with the combined use of natamycin and voriconazole. This antifungal combination is commonly included in most management protocols for fungal keratitis. Factors such as the use of corticosteroids and delayed diagnosis were noted to adversely affect the prognosis. This case and this systematic review underscores the potential for non-surgical management options in severe fungal keratitis.

Control of Mal secco disease in lemon by drip irrigation with fungicide

Mal secco disease of citrus is caused by the mitosporic ascomycete fungus Plenodomus tracheiphilus (formerly Phoma tracheiphila [Petri]). Mal secco is a highly destructive vascular disease of lemon and other citrus which is presently confined to the Mediterranean basin and has a marked economic impact on the citrus industry. The fungal pathogen infects the host tree by penetrating through wounds in the roots or canopy. Infection spreads quickly into the main branches and trunk and tree mortality usually ensues. The most typical symptoms are veinal chlorosis, leaf wilt, red discoloration of the xylem and dieback of twigs and branches. Current accepted control of the disease is mainly by sanitation of infected wood, and copper application during the winter to prevent germinating spores from infecting the plant. No effective chemical control for this disease has been reported. We present a drip-irrigation protocol to protect trees and control the disease in which we apply 250 g/ha of the triazole fungicide flutriafol five times a year. Progression of disease symptoms in the treated trees was inhibited by up to 81% compared to the untreated control, thereby significantly shortening the sanitation process and making it less costly than in untreated trees. Moreover, disease symptoms became less severe as the duration of treatment increased. We have treated orchards for 3 years, and present an effective commercial protocol for the growers which will help them control Mal secco disease.

Antioxidant properties and L-asparaginase activities of endophytic fungi from Cymbidium orchids.

This study profiled the various endophytic fungi isolated from the orchid Cymbidium sp. and their L-asparaginase production and antioxidant potential. The L-asparaginase production was first screened through qualitative plate screening then quantified by the Nesslerization method. The antioxidant potential was quantified via the 2,2-diphenyl-1-picrylhydrazyl assay. A total of 30 endophytic fungi were isolated and all fungal isolates exhibited various degrees of radical scavenging activities (45.28% to 76.4%). Isolate Lasiodiplodia theobromae (C11) had the highest antioxidant capacity, represented by the lowest IC50 value (5.75 mg/mL) and highest ascorbic acid equivalent antioxidant capacity value (12.17 mg/g). Additionally, 16 isolates produced L-asparaginase (53.33%), which includes primarily species of Fusarium proliferatum, Fusarium fujikuroi, Fusarium incarnatum, and Fusarium oxysporum. A new isolate has also been discovered from Cymbidium orchid, Buergenerula spartinae (C28), which showed the highest L-asparaginase activity (1.736 unit/mL). These findings supported the postulation that medicinal species of Orchidaceae such as Cymbidium sp. harbor endophytes that are producers of L-asparaginase and antioxidants with various potential applications.

Roles of Endophytic Fungi Isolated from Mangifera indica L. in Promoting Plant Growth.

Endophytic fungi have been shown to synthesize bioactive secondary metabolites, some of which promote plant growth through various mechanisms. In our previous study, endophytic fungi were isolated from mango trees (Mangifera indica L.). The present study examined fifty endophytic fungal isolates for mineral solubilization activity, ammonia production, and siderophore production. It was shown that these isolates could produce phytohormones indole-3-acetic acid and gibberellic acid, as well as inhibit plant pathogens, specifically Colletotrichum gloeosporioides and Lasiodiplodia theobromae. The results showed that all the isolated fungal endophytes exhibited various activities. Based on the findings, two fungal endophytes-Aureobasidium pullulans CY.OS 13 and Aspergillus tamarii CY.OS 144-were selected for dual inoculation in chili plants under pot-scale conditions to investigate their potential to improve growth-related traits such as seed germination, shoot and root length, biomass, and chlorophyll content. Seed treated with A. pullulans CY.OS 13 and/or A. tamarii CY.OS 144 showed a significant (p < 0.05) increase in seed germination and growth parameters of chili plants grown under pot-scale conditions. Particularly, chili plants whose seeds were injected with a combination of the two selected endophytic fungi showed the highest plant development traits. Therefore, the selected endophytic fungi have the potential to be used as biofertilizers, especially when combined. They could eventually replace chemical fertilizers because they are environmentally friendly, beneficial to humans, and can even promote sustainable agriculture.

Phylogenetic and Pathogenic Evidence Reveals Novel Host-Pathogen Interactions between Species of Lasiodiplodia and Citrus latifolia Dieback Disease in Southern Mexico.

Mexico ranks second in the world for Persian lime (Citrus latifolia) exports, making it the principal citrus exporter within the national citrus industry, exporting over 600,000 tons per year. However, diseases are the main factor reducing production, resulting in significant economic losses. Among these diseases, fungal diseases like dieback, caused by species of Lasiodiplodia, are an emerging issue in Persian lime. Symptoms include gummosis, twig and branch dieback, cankers, the necrosis of bark and wood, fruit mummification, and tree decline. The aim of this study was to investigate the occurrence and pathogenicity of the fungal species associated with twig and branch dieback, cankers, and decline of Persian lime trees in southern Mexico, and to elucidate the current status of the Lasiodiplodia species causing the disease in Mexico. During June, July, and August of 2023, a total of the 9229 Persian lime trees were inspected across 230 hectares of Persian lime orchards in southern Mexico, and symptoms of the disease were detected in 48.78% of the trees. Branches from 30 of these Persian lime trees were collected. Fungal isolates were obtained, resulting in a collection of 40 strains. The isolates were characterized molecularly and phylogenetically through the partial regions of four loci: the internal transcribed spacer region (ITS), the β-tubulin gene (tub2), the translation elongation factor 1-alpha gene (tef1-α), and the DNA-directed RNA polymerase II second largest subunit (rpb2). Additionally, pathogenicity was assessed, successfully completing Koch's postulates on both detached Persian lime branches and certified 18-month-old Persian lime plants. Through multilocus molecular phylogenetic identification, pathogenicity, and virulence tests, five species were identified as causal agents: L. iraniensis, L. lignicola, L. mexicanensis, L. pseudotheobromae, and L. theobromae. This study demonstrates that in southern Mexico, at least five species of the genus Lasiodiplodia are responsible for dieback in Persian lime. Additionally, this is the first report of L. lignicola and L. mexicanensis as causal agents of the disease in citrus, indicating novel host interactions between species of Lasiodiplodia and C. latifolia.