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Anthracnose, caused by Colletotrichum truncatum and C. gloeosporioides, is amongst the most serious diseases of soybean in China. Picoxystrobin, a quinone outside inhibitor fungicide, is commonly used for the control of anthracnose. Its resistance risk and mechanism in C. truncatum and C. gloeosporioides are unclear. In this study, the sensitivities of 128 C. truncatum and 121 C. gloeosporioides isolates to picoxystrobin were investigated, and unimodal distributions were observed with average EC50 values of 0.7740 and 1.1561 μg mL−1, respectively. Eleven picoxystrobin-resistant mutants of C. truncatum and six mutants of C. gloeosporioides were acquired, with EC50 values varying from 5.40–152.96 and 13.53–28.30 μg mL−1, respectively. Compared to the parental isolates, mutants showed similar or higher relative fitness in conidial production and germination, and pathogenicity. Collectively, the resistance risk of C. truncatum and C. gloeosporioides to picoxystrobin is moderate to high. There was positive cross-resistance between picoxystrobin and pyraclostrobin, but not between picoxystrobin and fluazinam, difenoconazole, or propiconazole. The G143S mutation in Cyt b protein was detected in seven high-resistant mutants of C. truncatum (RF>100), and G137R occurred in four moderate-resistant mutants (RF

Anthracnose fruit rot caused by Colletotrichum spp. is a serious production constraint causing severe marketable yield loss in chilli. Field evaluation of chilli accessions for resistance to Colletotrichum spp. depends on various factors affecting disease expression such as edaphic conditions, temperature, rainfall, humidity and other variables that are difficult to control, therefore considered less accurate. Also, high chances of cross contamination with different Colletotrichum species leads to inconclusive assays for specific pathogen species and isolate. To identify a stable and reliable screening method, various chilli accessions were subjected to in vitro pin-prick and nonwounding spray methods using a specific pathogen isolates. When chilli accessions were screened against C. gloeosporioides isolate 'IHRCg-1', the in vitro pin-prick method showed positive correlation with the nonwounding spray method, except in the accession PBC80. The change in bioassay influenced the disease reaction pattern in the accession PBC 80, probably the pin pricks break the basal cuticle defense mechanism that was retained in spray inoculation method indicating varied resistance pattern. However, in the accession PBC 81 stable resistance pattern was observed against isolates of both species viz., C. truncatum 'IIHR Ct-1' and C. gloeosporioides 'IIHR Cg-1' and in the accession PBC 80 against C. truncatum 'IIHR Ct-1' in both the inoculation methods that depicted the expression of resistance genes during both methods of inoculation. Based on disease development pattern, the red ripe chilli expressed a variant reaction to infection by C. truncatum and C. gloeosporioides. The peak anthracnose infection at 10 DAI and 14 DAI is an accurate duration to record 'IIHR Cg-1' and 'IIHR Ct-1' infection, respectively on chilli ripe fruit for assaying the resistance. [ABSTRACT FROM AUTHOR]

Plant extracts have been used as reducing and stabilising agents to synthesise various metal-based nanoparticles due to their cost-effective and eco-friendly nature. In the present work, a green and environment-friendly method is adopted for synthesising silver nanoparticles (Ag NPs) using a biowaste of dragon fruit (Hylocereus spp.) peel aqueous extract at 80ºC in an alkaline condition. The Ag NPs were characterised through various analytical and microscopic techniques. The UV-Vis spectra of Ag NPs showed a characteristic peak between 400 - 410 nm. Transmission and scanning electron microscopic studies confirmed spherical monodispersed particles with an average size of 7 nm. Energy-dispersive X-ray spectroscopy (EDX) confirmed the presence of silver and silver chloride among the principal elements. The X-ray powder diffraction (XRD) spectra showed the crystalline nature of synthesised silver and silver chloride nanoparticles. The synthesised nanoparticles showed potential antifungal activity against Colletotrichum truncatum spores in both in vitro conidial germination and spread plate assays. The efficacy of the synthesised NPs confirmed that these NPs could be used as potential antifungal agents against C. truncatum to control anthracnose in chilli. [ABSTRACT FROM AUTHOR]

Crop plant diseases caused by oomycetes and fungi have caused a lot of environmental, economic, and health damage to mankind. Streptomyces flaveus has been known to be able to suppress the growth of many oomycetes and fungal plant pathogens due to its ability to produce SW-B, an antibiotic. However, this antibiotic was reported not to be active enough to suppress the growth of a number of other fungal plant pathogens. In this paper, we demonstrate that S. flaveus RT1-1 was able to degrade fungal biomass and colloidal chitin due to producing chitinases. This promotes the potential of S. flaveus RT1-1 as a biocontrol agent that could help in achieving many sustainable development goals, to the benefit of mankind.

Invasions by fungal plant pathogens pose a significant threat to the health of agricultural ecosystems. Despite limited standing genetic variation, many invasive fungal species can adapt and spread rapidly, resulting in significant losses to crop yields. Here, we report on the population genomics of Colletotrichum truncatum, a polyphagous pathogen that can infect more than 460 plant species, and an invasive pathogen of soybean in Brazil. We study the whole‐genome sequences of 18 isolates representing 10 fields from two major regions of soybean production. We show that Brazilian C. truncatum is subdivided into three phylogenetically distinct lineages that exchange genetic variation through hybridization. Introgression affects 2%–30% of the nucleotides of genomes and varies widely between the lineages. We find that introgressed regions comprise secreted protein‐encoding genes, suggesting possible co‐evolutionary targets for selection in those regions. We highlight the inherent vulnerability of genetically uniform crops in the agro‐ecological environment, particularly when faced with pathogens that can take full advantage of the opportunities offered by an increasingly globalized world. Finally, we discuss "the means, motive and opportunity" of fungal pathogens and how they can become invasive species of crops. We call for more population genomic studies because such analyses can help identify geographical areas and pathogens that pose a risk, thereby helping to inform control strategies to better protect crops in the future. [ABSTRACT FROM AUTHOR]

Ecological interactions are a fairly overlooked component in agriculture, despite their known potential in productivity, pest and disease regulation. In this study, we assessed whether a potential low pathogenic congeneric competitor of Colletotrichum gloeosporioides could decrease disease onset in yams. We set up an experiment with artificial drop inoculation on detached leaves, with individual controls and treatments as either co‐inoculation or inoculation with a harmless competitor 24 h prior to inoculating the pathogen. Our results demonstrate that direct admixing translated into accrued competition and disease symptoms, while prior inoculation of the competitor tended to decrease symptom development. There was variation in how varieties responded to treatments and in strain competitive ability altering the protective effect, but nevertheless these results suggest that incorporating such interactions in breeding programmes or working towards increased use of commensals in agriculture might confer improved disease control for crops. [ABSTRACT FROM AUTHOR]

Citrullus lanatus (Thumb Mansf.) (Egusi melon) is an important vegetable in West Africa grown for its edible seeds and oil. Its productivity is limited by leaf blight disease (LBD) which is dangerous to humans and the environment to control with synthetic fungicides. This study investigated the antifungal activity of some botanicals on Colletotrichum truncatum and Colletotrichum gloeosporioides causing LBD of Egusi melon. Four concentrations (5.0, 7.5, 10.0 and 12.5%) of aqueous extracts of Phyllanthus amarus leaves (PaL), Passiflora foetida leaves (PfL), Costus afer leaves (CaL), -stems (CaS) and -rhizomes (CaR) were evaluated against the pathogens in vitro, using agar poisoning. These extracts, except CaS (at 5, 10 and 50% w/v/50 seeds), were also evaluated for seed treatment under screen-house conditions. Data were collected on colony diameter reduction, sporulation, disease incidence, severity, seed germination, vine length, number of leaves and number of vines. Fungitoxicity of the botanicals varied with plant parts and extract concentrations. Phyllanthus amarus (7.5–10%), PfL (12.5%) and CaR (5–10%) significantly (p˂0.05) reduced C. truncatum mycelia growth (by 8.5–44.5%) and sporulation (by 22.3–90.9%), whereas 5–10% of PaL, PfL, CaR and CaL reduced growth (14.3–33.3%) and sporulation (9.6–96.4%) of C. gloeosporioides. Fungitoxicity was lowest in CaS. The botanicals, when used in seed treatment, significantly reduced disease incidence and severity, increased vine length and number of leaves without any effect on seed germination, while PfL, PaL and CaR (at 5, 10 and 50% w/v/50 seeds) were as effective as the synthetic fungicide (Mancozeb). High contents (mg/100 g) of alkaloids, flavonoids, saponins, tannins, glycosides, steroids and phenols detected from the botanicals might have enhanced their antifungal property. The high fungicidal potentials of P. amarus, P. foetida and C. afer (leaf and rhizome) on leaf blight of Egusi melon can be harnessed as safe biopesticides towards a better crop protection. [ABSTRACT FROM AUTHOR]

Anthracnose lima beans, caused by Colletotrichum truncatum can cause severe losses in production. Although there are difficulties in controlling the pathogen, studies concentrate on genetic resistance through local varieties with high genetic resistance to the pathogen. The objective of this work was to evaluate the temporal progress of lima beans anthracnose under field conditions. The experiments were carried out in the experimental farm Chã de Jardim, Federal University of Paraíba, Areia, Brazil in 2015 and 2017. Nine creole varieties of lima beans (Phaseolus lunatus) represented by UFPB02, UFPB04, UFPB05, UFPB06, UFPB11, UFPB13, UFPB14, UFPB19 and UFPB20, were tested at seven day intervals to determine incidence and severity, considering the natural occurrence of anthracnose in plants. Area under the anthracnose progress curve and disease index were assessed. The productivity components of the varieties were obtained at the end of the crop cycle. The experimental design was randomized blocks with four replicates. We found an interaction between local varieties and environments, creating favorable and unfavorable environments to disease development. Genetic variability among lima bean varieties was observed regarding resistance to C. truncatum, where the UFPB04 and UFPB20 varieties were considered more resistant to the pathogen and able to be used in breeding programs. [ABSTRACT FROM AUTHOR]

The cysteine-rich receptor-like kinases (CRKs) belong to the plant receptor-like kinases family and have multitudinous roles, including stress responses. However, information on CRKs in chili pepper (Capsicum annuum L.) plants is limited. In this study, a total of 22 C. annuum CRKs (CaCRKs) have been identified in the chili genome. All the identified CaCRKs were mapped onto different chili chromosomes. The gene duplication analysis revealed that five gene pairs had the Ka/Ks ratio greater than one, suggesting the positive selection of CaCRKs in chili. Phylogenetic analysis grouped the CaCRKs into four groups alongside other plant CRKs. The structural characterization of the CaCRKs revealed that all of them carry the signature domains and motifs. The gene ontology analysis predicted their major potential functions to be stress response and protein kinase activity. The expression analysis the CaCRKs in two contrasting chili varieties under Colletotrichum truncatum infection added valuable insights into their involvement in chili-C. truncatum interactions. The comparison of expression dynamics suggested that CaCRK13 could be a potential candidate gene in regulating chili defense against anthracnose pathogen. Moreover, the results of this study will help to get insights into the chili CRKs and their involvement in chili defense response against C. truncatum. [ABSTRACT FROM AUTHOR]

Biopolymer-based metal nanocomposites are gaining importance due to their safety, stability, and ease of synthesis. Chitosan and silver-based nanoparticles have been found to be effective as anti-fungal agents. In this study, we tested the fungicidal effect of green synthesized chitosan silver nanocomposites (CS-AgNPs) against the chilli anthracnose pathogen Colletotrichum truncatum (syn. C. capsici). The nanoparticles were synthesized at 90 ± 1 °C under alkaline condition. Chitosan was used as a reducing and stabilizing agent in the synthesis. The formation of nanoparticles (NPs) was indicated by a change in the colour of the solution to yellow. UV-Visible spectroscopy of the synthesized nanoparticles showed a surface plasmon resonance peak between 406 and 420 nm. The synthesized silver nanoparticles were small, and the average particle size distribution was 4 nm, as characterized by TEM and FESEM. The Zeta potential measurement of the synthesized nanoparticles ranged from + 41.9 mV and + 50.5 mV. The nanoparticles were further characterized by XRD and FTIR analysis. The nanocomposites showed antifungal activity against C. truncatum in an in vitro conidial germination assay even at a concentration of 0.0005%. In vivo assay using detached chilli fruit (Capsicum annuum) showed that the nanocomposites significantly inhibited anthracnose in both preventive and curative measures. Even when applied at a concentration of 0.0625%, the nanocomposites exhibited growth-promoting activity with chilli seeds. Thus, the synthesized nanocomposites have a dual benefit of growth promotion as well as an effective antifungal agent in preventing postharvest anthracnose disease in chilli.

Anthracnose caused by Colletotrichum truncatum (C. truncatum) fungus, a seriously damaged in many soybean growing areas, has almost no effective control strategy. Recently, biostimulants for disease prevention of plants have been considered a feasible solution. In this study, the chitinase-induced effect on soybean plants of various oligochitosan-Zn2+ (OC–Zn2+) complexes prepared from gamma radiation-degraded oligochitosans with the different molecular weights (Mw) of 2.5, 5.1, and 7.8 kDa was investigated in the first time. The potted soybean plants in a greenhouse were treated with a foliar spray of OC-Zn2+ solutions at 50 ppm and inoculated with a disease by a fungal spore suspension spray of C. truncatum to assess the chitinase-elicited effect. The chitinase activity (CA) which described in milliunits per gram (mU/g) of fresh leaves in soybean was determined by the optical density measurement method based on the reducing sugar reaction. The obtained results indicated that the OC-Zn2+ complex exhibited a synergistic effect of OC and Zn2+. The OC5.1-Zn2+ complex prepared from the OC with Mw of 5.1 kDa showed a high chitinase-induced effect with the CA ∼12 mU/g. The OC-Zn2+ complexes with effective chitinase inductivity could be feasibly produced on a large scale. Thus, the complexes have been promising to be potentially applied in sustainable agriculture production.

Chilli is an universal spice cum solanaceous vegetable crop rich in vitamin A, vitamin C, capsaicin and capsanthin. Its cultivation is highly threatened by fruit rot disease which cause yield loss as high as 80–100% under congenial environment conditions. Currently actinobacteria are considered as eco-friendly alternatives to synthetic fungicides at pre and post-harvest pathosystems. Hence, this research work focuses on the exploitation of rhizospheric, phyllospheric and endophytic actinobacteria associated with chilli plants for their antagonistic activity against fruit rot pathogens viz., Colletotrichum scovillei, Colletotrichum truncatum and Fusarium oxysporum. In vitro bioassays revealed that the actinobacterial isolate AR26 was found to be the most potent antagonist with multifarious biocontrol mechanisms such as production of volatile, non-volatile, thermostable compounds, siderophores, extracellular lytic enzymes. 16S rRNA gene sequence confirmed that the isolate AR26 belongs to Streptomyces tuirus. The results of detached fruit assay revealed that application of liquid bio-formulation of Stretomyces tuirus @ 10 mL/L concentration completely inhibited the development of fruit rot symptoms in pepper fruits compared to methanol extracts. Hence, the present research work have a great scope for evaluating the biocontrol potential of native S. tuirus AR26 against chilli fruit rot disease under field condition as well against a broad spectrum of post-harvest plant pathogens. [ABSTRACT FROM AUTHOR]

Tomato (Solanum lycopersicum L.) is a popular nutritious vegetable crop grown in Malaysia and other parts of the world. However, fungal diseases such as anthracnose pose significant threats to tomato production by reducing the fruit quality and food value of tomato, resulting in lower market prices of the crop globally. In the present study, the etiology of tomato anthracnose was investigated in commercial tomato farms in Sabah, Malaysia. A total of 22 fungal isolates were obtained from anthracnosed tomato fruits and identified as Colletotrichum species, using morphological characteristics. The phylogenetic relationships of multiple gene sequence alignments such as internal transcribed spacer (ITS), β-tubulin (tub2), glyceraldehyde 3-phosphate dehydrogenase (gapdh), actin (act), and calmodulin (cal), were adopted to accurately identify the Colletotrichum species as C. truncatum. The results of pathogenicity tests revealed that all C. truncatum isolates caused anthracnose disease symptoms on inoculated tomato fruits. To our knowledge, the present study is the first report of tomato anthracnose caused by C. truncatum in Malaysia. The findings of this study will be helpful in disease monitoring, and the development of strategies for effective control of anthracnose on tomato fruits. [ABSTRACT FROM AUTHOR]

Copyright of Acta Agriculturae Zhejiangensis is the property of Acta Agriculturae Zhejiangensis Editorial Office 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.)

Anthracnose is a disease caused by Colletotrichum species. They are well known as major plant pathogens, and a black stem disease, specifically caused by Colletotrichum truncatum and primarily infecting sword bean (Canavalia gladiata), was observed in the Yunnan province, China. To aid disease management and to determine pathogenic characteristics, the species causing the leaf spot disease of hairy vetch was verified as C. truncatum. A sequence analysis of the ITS, ACT, GAPDH, and HIS3 genes was conducted, as well as morphological and cultural characteristics, to identify this Colletotrichum species, which has curved conidia. C. truncatum isolates from sword bean formed a distinctive group among Colletotrichum species, including those that infect other forage and field crops. Artificially inoculated sword bean seedlings showed typical symptoms of anthracnose, which were similar to field observations. To the best of our knowledge, this is the first report of C. truncatum causing black stem disease on sword beans in China. [ABSTRACT FROM AUTHOR]

Diseases caused by Colletotrichum fungi result in major agricultural losses worldwide. Here, we present two draft genomes of Colletotrichum spp. responsible for foliar and pod blight on African yam bean. Colletotrichum siamense and Colletotrichum truncatum assemblies totalled 55.8 Mb in 563 contigs and 54.8 Mb in 1,240 contigs, respectively.

Iris lactea is a wide ground cover plant of importance throughout courtyards, trees and roads. From May to September in 2020 and 2021, I. lactea planted in Beijing showed white to yellow spots with black conidiomata and could lead blight expanded down from the tip of leaves. In this study, ninety‐six diseased leaves were collected from nineteen regions in Beijing, and a total of fifty‐nine Colletotrichum isolates were obtained from the leaf spots. All isolates were identified as Colletotrichum truncatum by polyphasic analyses, combing morphology and phylogeny of combined the internal transcribed spacer of rDNA region (ITS), actin (act), chalcone synthetase (chs), the genes of glyceraldehyde‐3‐phosphate dehydrogenase (gapdh) and β‐tubulin (tub2). Koch's postulates were confirmed by a pathogenicity test using conidial suspensions (1 × 106 conidia/ml) on fresh leaves of the host, re‐isolation and identification. Until now, this is the first confirmed report of a new anthracnose disease of I. lactea caused by C. truncatum in China. [ABSTRACT FROM AUTHOR]

Anthracnose, caused by Colletotrichum truncatum , leads to large-scale reduction in quality and yield in soybean production. Limited information is available regarding the molecular mechanisms of resistance to anthracnose in soybean. We conducted a transcriptomic and targeted metabolomic analysis of pods from two soybean lines, "Zhechun No. 3" (ZC3) and ZC-2, in response to C. truncatum infection. Factors contributing to the enhanced resistance of ZC-2 to anthracnose compared with that of ZC3, included signal transduction (jasmonic acid, auxin, mitogen-activated protein kinase, and Ca2+ signaling), transcription factors (WRKY and bHLH), resistance genes (PTI1 , RPP13 , RGA2 , RPS6 , and ULP2B), pathogenesis-related genes (chitinase and lipid transfer protein), and terpenoid metabolism. Targeted metabolomic analysis revealed that terpenoid metabolism responded more promptly and more intensely to C. truncatum infection in ZC-2 than in ZC3. In vitro antifungal activity and resistance induction test confirmed that jasmonic acid, auxin signaling and terpenoids played important roles in soybean resistance to anthracnose. This research is the first study to explore the molecular mechanisms of soybean resistance to anthracnose. The findings are important for in-depth analysis of molecular resistance mechanisms, discovery of resistance genes, and to expedite the breeding of anthracnose-resistant soybean cultivars. [ABSTRACT FROM AUTHOR]

Copyright of Revista Caatinga is the property of Revista Caatinga 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.)

Anthracnose, caused by Colletotrichum truncatum, leads to large-scale reduction in quality and yield in soybean production. Limited information is available regarding the molecular mechanisms of resistance to anthracnose in soybean. We conducted a transcriptomic and targeted metabolomic analysis of pods from two soybean lines, “Zhechun No. 3” (ZC3) and ZC-2, in response to C. truncatum infection. Factors contributing to the enhanced resistance of ZC-2 to anthracnose compared with that of ZC3, included signal transduction (jasmonic acid, auxin, mitogen-activated protein kinase, and Ca2+ signaling), transcription factors (WRKY and bHLH), resistance genes (PTI1, RPP13, RGA2, RPS6, and ULP2B), pathogenesis-related genes (chitinase and lipid transfer protein), and terpenoid metabolism. Targeted metabolomic analysis revealed that terpenoid metabolism responded more promptly and more intensely to C. truncatum infection in ZC-2 than in ZC3. In vitro antifungal activity and resistance induction test confirmed that jasmonic acid, auxin signaling and terpenoids played important roles in soybean resistance to anthracnose. This research is the first study to explore the molecular mechanisms of soybean resistance to anthracnose. The findings are important for in-depth analysis of molecular resistance mechanisms, discovery of resistance genes, and to expedite the breeding of anthracnose-resistant soybean cultivars.

Copyright of Tecno-Lógica is the property of Tecno-Logica 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.)

Chilli is an universal spice cum solanaceous vegetable crop rich in vitamin A, vitamin C, capsaicin and capsanthin. Its cultivation is highly threatened by fruit rot disease which cause yield loss as high as 80–100% under congenial environment conditions. Currently actinobacteria are considered as eco-friendly alternatives to synthetic fungicides at pre and post-harvest pathosystems. Hence, this research work focuses on the exploitation of rhizospheric, phyllospheric and endophytic actinobacteria associated with chilli plants for their antagonistic activity against fruit rot pathogens viz., Colletotrichum scovillei, Colletotrichum truncatum and Fusarium oxysporum. In vitro bioassays revealed that the actinobacterial isolate AR26 was found to be the most potent antagonist with multifarious biocontrol mechanisms such as production of volatile, non-volatile, thermostable compounds, siderophores, extracellular lytic enzymes. 16S rRNA gene sequence confirmed that the isolate AR26 belongs to Streptomyces tuirus. The results of detached fruit assay revealed that application of liquid bio-formulation of Stretomyces tuirus @ 10 mL/L concentration completely inhibited the development of fruit rot symptoms in pepper fruits compared to methanol extracts. Hence, the present research work have a great scope for evaluating the biocontrol potential of native S. tuirus AR26 against chilli fruit rot disease under field condition as well against a broad spectrum of post-harvest plant pathogens.

Tomato (Solanum lycopersicum L.) is a popular nutritious vegetable crop grown in Malaysia and other parts of the world. However, fungal diseases such as anthracnose pose significant threats to tomato production by reducing the fruit quality and food value of tomato, resulting in lower market prices of the crop globally. In the present study, the etiology of tomato anthracnose was investigated in commercial tomato farms in Sabah, Malaysia. A total of 22 fungal isolates were obtained from anthracnosed tomato fruits and identified as Colletotrichum species, using morphological characteristics. The phylogenetic relationships of multiple gene sequence alignments such as internal transcribed spacer (ITS), β-tubulin (tub2), glyceraldehyde 3-phosphate dehydrogenase (gapdh), actin (act), and calmodulin (cal), were adopted to accurately identify the Colletotrichum species as C. truncatum. The results of pathogenicity tests revealed that all C. truncatum isolates caused anthracnose disease symptoms on inoculated tomato fruits. To our knowledge, the present study is the first report of tomato anthracnose caused by C. truncatum in Malaysia. The findings of this study will be helpful in disease monitoring, and the development of strategies for effective control of anthracnose on tomato fruits.

Anthracnose is a disease caused by Colletotrichum species. They are well known as major plant pathogens, and a black stem disease, specifically caused by Colletotrichum truncatum and primarily infecting sword bean (Canavalia gladiata), was observed in the Yunnan province, China. To aid disease management and to determine pathogenic characteristics, the species causing the leaf spot disease of hairy vetch was verified as C. truncatum. A sequence analysis of the ITS, ACT, GAPDH, and HIS3 genes was conducted, as well as morphological and cultural characteristics, to identify this Colletotrichum species, which has curved conidia. C. truncatum isolates from sword bean formed a distinctive group among Colletotrichum species, including those that infect other forage and field crops. Artificially inoculated sword bean seedlings showed typical symptoms of anthracnose, which were similar to field observations. To the best of our knowledge, this is the first report of C. truncatum causing black stem disease on sword beans in China.

Anthracnose is a destructive disease of alfalfa (Medicago sativa) that causes severe yield losses. Biological control can be an effective and eco-friendly approach to control this alfalfa disease. In the present study, Bacillus amyloliquefaciens LYZ69, previously isolated from healthy alfalfa roots, showed a strong in vitro antifungal activity against Colletotrichum truncatum, an important causal agent of anthracnose of alfalfa. The strain LYZ69 protected alfalfa plants (biocontrol efficacy of 82.59%) from anthracnose under greenhouse conditions. The cell-free culture (CFC) of LYZ69 (20%, vol/vol) caused 60 and 100% inhibition of mycelial growth and conidial germination, respectively. Highperformance liquid chromatography tandem mass spectrometry separated and identified cyclic lipopeptides (LPs) such as bacillomycin D and fengycin in the CFC of LYZ69. Light microscopy and scanning electron microscopy revealed that the mixture of cyclic LPs produced by LYZ69 caused drastic changes in mycelial morphology. Fluorescence microscopy showed that the LPs induced reactive oxygen species accumulation and caused apoptosis-like cell death in C. truncatum hyphae. In summary, our findings provide evidence to support B. amyloliquefaciens LYZ69 as a promising candidate for the biological control of anthracnose in alfalfa. [ABSTRACT FROM AUTHOR]

Yam (Dioscorea spp.) is a significant tuber crop. In October 2022, yam (Dioscorea opposita Thunb.) leaves exhibiting typical anthracnose symptoms were observed at the Yam Germplasm Resource Nursery of Wen County, Jiaozuo City, Henan Province, China. The disease incidence was recorded at 92.05%. The symptoms manifested as brown to dark brown circular or irregular large spots on the leaves, some of which displayed noticeable irregular concentric rings. A total of 23 isolates were obtained, with JCHN023-1 and JCHN003 isolates being the representative. The pathogen was successfully re-isolated from lesions of inoculated leaves, fulfilling Koch's postulates. Morphologically, the conidia appeared colorless, crescent-shaped, circular blunt at both ends, and measured (15.2-) 18.2–30 (−34.1) × (2.1-) 2.3–3.9 (−4.2) μm in length (average = 24.1 × 3.1 μm) without septa. The setae were black-brown and exhibited 1-4 septa. Subsequently, a multigene phylogenetic analysis, involving internal transcribed spacer (ITS), partial actin (ACT), chitin synthase 1 (CHS-1) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH), identified the fungus as Colletotrichum truncatum. Inoculation of detached leaves from 10 varieties of D. opposita confirmed their broad-spectrum pathogenicity to yam. This represents the first report of yam anthracnose caused by C. truncatum in China and provides a theoretical foundation for yam anthracnose prevention and control. • Yam anthracnose is a severe disease that widely affects yam yield. • This is the first report of yam anthracnose caused by Colletotrichum truncatum in China. • Representative strains can infect various varieties of yam. [ABSTRACT FROM AUTHOR]

We report a sensitive lateral flow assay (LFA) in which the assay colour change originated from reporter labels constructed from silica spheres (radius = 450 nm) coated with approximately 3.9 × 103 gold nanoparticles (radius = 8.5 nm). These reporter labels were modified with DNA and deposited in the conjugation area of an LFA device assembled on wax-patterned Fusion 5 paper. Test and control zones of the device were pre-loaded with capture probe formed by avidin-coated mesoporous silica nanoparticles attached with biotin-tagged DNA sequences. Proof-of-concept was demonstrated by the detection of a partial sequence of the actin gene of Colletotrichum truncatum. The DNA target could be detected with an LOD of 46 pM, which was 5 times lower than a comparative assay using gold nanoparticles alone. The assay showed good selectivity against the Colletotrichum species C. scovillei and C. gloeosporioides , as well as against DNA from the fungal genera Aspergillus niger and Alternaria alternata. There was negligible change in sensor response over storage for one month at room temperature. The LFA was used to detect PCR products following extraction from mycelium. [Display omitted] • Lateral flow assay (LFA) for partial sequence of actin gene of Colletotrichum truncatum. • In conjugation area, reporter probe DNA attached to silicon spheres coated with gold nanoparticles. • Better limit of detection for same species compared to LFA using only gold nanoparticles as reporter signal. • Good selectivity against C. scovillei and C. gloeosporioides , and DNA from the fungal genera A. niger and A. alternata. • Detection of real samples, extracted from mycelium, following PCR. [ABSTRACT FROM AUTHOR]

The incidence of soybean anthracnose reduces yields and leads to financial losses. Among several management practices to control this disease, use of phosphites (Phi) can act by providing mineral nutrition, inducing resistance in the host and causing direct toxicity to the pathogen. The aim of this study was to investigate the effectiveness of phosphites in the management of anthracnose in soybean pods, in the transmission of the pathogen and the activities of plant defense enzymes. Soybean plants were sprayed with potassium (KPhi), manganese (MnPhi), zinc (ZnPhi), copper (CuPhi) phosphites and fungicide epoxiconazole + piraclostrobin at V4, R1 and R3 stages and inoculated with Colletotrichum truncatum isolate in the R3 stage. The anthracnose severity, the incidence of C. truncatum in soybean seeds, activities of catalase (CAT), peroxidase (POX) and superoxide dismutase (SOD) enzymes and contents of soluble lignin and total soluble phenols were evaluated. KPhi, CuPhi and MnPhi reduced the severity of anthracnose, the transmission of the C. truncatum, increased lignin content and SOD, POX and CAT enzymatic activity. Phosphites can be utilized in the management of anthracnose in soybean. [ABSTRACT FROM AUTHOR]

Soybean (Glycine max) is one of the most important cultivated plants worldwide as a source of protein‐rich foods and animal feeds. Anthracnose, caused by different lineages of the hemibiotrophic fungus Colletotrichum, is one of the main limiting factors to soybean production. Losses due to anthracnose have been neglected, but their impact may threaten up to 50% of the grain production. Taxonomy: While C. truncatum is considered the main species associated with soybean anthracnose, recently other species have been reported as pathogenic on this host. Until now, it has not been clear whether the association of new Colletotrichum species with the disease is related to emerging species or whether it is due to the undergoing changes in the taxonomy of the genus. Disease symptoms: Typical anthracnose symptoms are pre‐ and postemergence damping‐off; dark, depressed, and irregular spots on cotyledons, stems, petioles, and pods; and necrotic laminar veins on leaves that can result in premature defoliation. Symptoms may evolve to pod rot, immature opening of pods, and premature germination of grains. Challenges: As accurate species identification of the causal agent is decisive for disease control and prevention, in this work we review the taxonomic designation of Colletotrichum isolated from soybean to understand which lineages are pathogenic on this host. We also present a comprehensive literature review of soybean anthracnose, focusing on distribution, symptomatology, epidemiology, disease management, identification, and diagnosis. We consider the knowledge emerging from population studies and comparative genomics of Colletotrichum spp. associated with soybean providing future perspectives in the identification of molecular factors involved in the pathogenicity process. Useful website: Updates on Colletotrichum can be found at http://www.colletotrichum.org/. All available Colletotrichum genomes on GenBank can be viewed at http://www.colletotrichum.org/genomics/. [ABSTRACT FROM AUTHOR]

In the present study, Paenibacillus dendritiformis, Trichoderma harzianum, and Trichoderma asperellum were appraised as potential biocontrol agents that induce resistance in chilli (Capsicum annuum) against the devastating pathogen Colletotrichum truncatum, which causes anthracnose. Bright-field and scanning electron micrographs showed the hyphal degradation, lysis, and abnormal swelling in C. truncatum against P. dendritiformis in a dual plate assay. Under greenhouse conditions, chilli seeds pretreated with P. dendritiformis, T. asperellum, T. harzianum, and T. asperellum + T. harzianum by soil soak method inflicted an induced systemic resistance (ISR) in chilli against a C. truncatum-challenged condition. In chilli, the disease index percentage was significantly reduced in the T. asperellum + T. harzianum-treated seeds, followed by the T. harzianum-, T. asperellum-, and P. dendritiformis-treated seeds as compared to the untreated and challenged, respectively. Chilli seeds were primed with T. asperellum + T. harzianum (78.67%), which revealed maximum disease protection under the challenged condition, followed by T. harzianum (70%), T. asperellum (64%), and P. dendritiformis (56%) as compared to untreated and C. truncatum-challenged (6%) condition served as control. The seeds that were pretreated with biocontrol agents (BCAs) inflicted ISR against C. truncatum by enhancing the activity of defence-related enzymes (superoxide dismutase (SOD), peroxidase (POX), polyphenol oxidase (PPO), catalase (CAT), ascorbate peroxidase (APX), guaiacol peroxidase (GPX) and phenylalanine ammonia-lyase (PAL)), accumulating phenolic compounds, and increasing the relative chlorophyll content in chilli. Nitroblue tetrazolium (NBT) and 3,30 -Diaminobenzidine (DAB) stains were used to detect the accumulation of superoxide anion and hydrogen peroxide that appeared nearby the fungal infection sites. The accumulation of reactive oxygen species (O2 − and H2O2 ) in the pathogen-inoculated leaves was a maximum of 48 hpi, followed by P. dendritiformis, T. asperellum, T. harzianum, and T. asperellum + T. harzianum treated tissue upon C. truncatum-challenged condition as compared to the control. Overall, our results showed the potential of T. harzianum, T. asperellum, and P. dendritiformis as biocontrol agents that prevent infection by C. truncatum and inflict an induced systemic resistance in chilli by enhancing the biosynthesis of phenolic compounds, defence and antioxidative enzymes, and reducing the lesion development and reactive oxygen species accumulation. This is the first report of induced systemic resistance against anthracnose in chilli obtained by application of T. harzianum, T. asperellum and P. dendritiformis, through seed priming. [ABSTRACT FROM AUTHOR]

The transition toward sustainable agriculture requires rethinking cropping systems in the light of less intensive and chemically reliant practices. Weed management is one of the target practices to evolve cropping systems with decreased impact on the environment. While softened management will lead to increased weeds/crops coexistence, it is of importance to assess the relative benefits and drawbacks of new practices. Among the potential drawbacks of weeds/crops coexistence, disease risk may increase if weeds are hosting pathogens. In this study, we assessed the potential of weeds for hosting pathogenic generalist fungi known to translate into disease in crops. We first describe prevalence in fields after harvest and relate prevalence to species characteristics and communities. Then, we directly test the idea that weeds serve as inoculums sources during cropping with a natural experiment. This study highlights variation in host skill among feral weeds for Colletotrichum species, including potential congeneric sub-specialization on different weeds within communities. Last, prevalence within fields was more correlated to focal crop inoculation rates compared to local weed load, but there was a significant correlation effect with prevalence on weeds in the vicinity of fields, suggesting that weeds are mediating disease levels at the local scale, too. Results pointed to the importance of weed host skill in disease risk yet open the door to the potential control of pathogens via targeted weed management. [ABSTRACT FROM AUTHOR]

Although, the C2H2 zinc finger (ZF) family of plant transcription factors have been implicated in multiple biological processes, they are yet to be characterized in the economically important chilli pepper (Capsicum annuum). In this study, a total of 79 C2H2 ZF genes were identified in the pepper genome. Phylogenetic analysis categorized the pepper C2H2 ZF (CaZF) members into five subfamilies each with unique conserved domains and functions. Genomic organization revealed that CaZF genes have variable number of introns consistent with the characteristics defined by the evolutionary analysis. Segmental duplication-based purifying selection contributed to the expansion of CaZF genes in pepper. Additionally, 11 CaZF genes were identified as targets for 38 miRNAs indicating their role in post-transcriptional silencing-mediated genetic regulation. Gene expression analysis revealed that 18 CaZF genes were differentially expressed post-infection with the anthrocnose pathogen Colletotrichum truncatum, uncovering their potential function in pepper response to biotic stresses. Moreover, CaZFs were significantly induced post-treatment with methyl jasmonate and ethylene indicating their role in defense signaling. Notably, the MeJA responsive cis-elements were detected in the promoter regions of majority of CaZF genes, suggesting that CaZFs may be implicated in defense-responsive signal cross talking. Additionally, 18 CaZF genes were differentially expressed under drought and heat treatment, indicating their involvement in plant response to abiotic stresses. Overall, a comprehensive analysis of CaZF gene family in pepper provided significant insights into the understanding of C2H2 ZF-mediated stress regulation network, which would benefit the genetic improvement of pepper and other allied plants. [ABSTRACT FROM AUTHOR]

Receptor like kinases (RLKs) are preserved upstream signaling molecules which regulate several biological processes from plant development to various stress adaptation programs. Non arginine aspartate (non-RD) a prominent class of RLKs plays a significant role in disease resistance and apoptosis in plants. In present investigation, a comprehensive in silico analysis for non-RD Kinase gene family as well as identification of gene structures, sequence similarity, chromosomal localization, gene duplication analysis, promoter analysis, transcript expression profiles and phylogenic studies were done. In this study, twenty-six genes were observed on nine out of twelve chromosomes. All these genes were clustered into five subfamilies under large monophyletic group termed as Interleukin-1 Receptor-Associated Kinase (IRAK) family. Some of the important physiochemical properties of twenty-six proteins are determined and ranged in the following order: (a) Amino acids size ranged from (620 to 1781) (b) Molecular weight ranged as of (70.11 to 197.11 KDa) and (c) Theoretical PI ranged from (5.69 to 8.63) respectively. Structural diversity in genomic structure among non-RD kinase gene family was identified and presence of pathogen induced cis regulatory elements including STRE, MYC, MYB, and W box were found. Expression profiles revealed the potential ability of three genes CaRLK1 from LRRXII and CaRLK15,16 from stress antifung subfamily were pointedly upregulated beyond the severe stress time period (9 DAI) in anthracnose resistant genotype PBC-80 in response to Colletotrichum truncatum infection. Subsequently, in silico studies from the available genome sequencing data helped us to identify candidate genes tangled in inducing disease resistance. [ABSTRACT FROM AUTHOR]

Fungal diseases lead to significant losses in soybean yields and a decline in seed quality; such is the case of the Asian soybean rust and anthracnose caused by Phakopsora pachyrhizi and Colletotrichum truncatum, respectively. Currently, the development of transgenic plants carrying antifungal defensins offers an alternative for plant protection against pathogens. This paper shows the production of transgenic soybean plants expressing the NmDef02 defensin gene using the biolistic delivery system, in an attempt to improve resistance against diseases and reduce the need for chemicals. Transgenic lines were assessed in field conditions under the natural infections of P. pachyrhizi and C. truncatum. The constitutive expression of the NmDef02 gene in transgenic soybean plants was shown to enhance resistance against these important plant pathogens. The quantification of the P. pachyrhizi biomass in infected soybean leaves revealed significant differences between transgenic lines and the non-transgenic control. In certain transgenic lines there was a strong reduction of fungal biomass, revealing a less severe disease. Integration and expression of the transgenes were confirmed by PCR, Southern blot, and qRT-PCR, where the Def1 line showed a higher relative expression of defensin. It was also found that the expression of the NmDef02 defensin gene in plants of the Def1 line did not have a negative effect on the nodulation induced by Bradyrhizobium japonicum. These results indicate that transgenic soybean plants expressing the NmDef02 defensin gene have a substantially enhanced resistance to economically important diseases, providing a sound environmental approach for decreasing yield losses and lowering the burden of chemicals in agriculture.

Anthracnose caused by Colletotrichum truncatum is a major fungal disease of soybean, especially vegetable soybean (edamame). Studies of this disease have mainly focused on resistance evaluation, but the primary methods used—in vivo inoculation of pods or plants under greenhouse or field conditions—have limitations with respect to accuracy, stability, scale, and environmental safety. In this study, we developed a method for inoculating pods in vitro by soaking in a mycelial suspension. We optimized the crucial components, including the mycelial suspension concentration (40 to 60 mg mL−1), the maturity of the sampled pods (15 days after flowering), and the post-inoculation incubation period (5 days). Application of the mycelial suspension by soaking rather than spraying improved the efficiency of inoculation and made large-scale evaluation possible. Using this method, we evaluated 589 soybean germplasm resources (275 cultivars, 233 landraces, and 81 wild accessions). We identified 25 highly resistant cultivars, 11 highly resistant landraces, but only one highly resistant wild accession. Our results will aid future research on soybean anthracnose resistance, including gene discovery, the elucidation of molecular mechanisms, and the breeding of resistant cultivars.

• Antifungal activity of aqueous extracts from wild and nursery Diospyros cuneata was similar. • Antifungal activity of aqueous extracts from Diospyros cuneata leaves collected in the dry season was the highest. • Abundance of metabolites of aqueous extracts from wild plants of the dry season was the highest. • Hexane fractions of the nursery plants were the most active. • HPTLC-bioautography is a fast technique to correlate antifungal activity with metabolites. The synthetic fungicides used in agriculture cause environmental and human health problems and favor the rise of resistant fungal strains. An alternative to decrease this negative impact is those products derived from native plants. Nevertheless, anthropogenic activities cause the loss of native plants with biotechnological potential, and the ex situ conservation is one way to protect them even though their biological activity may decrease in comparison with wild plants. Diospyros cuneata Standl., native species from the coastal dune of Yucatan, was collected in dry and rainy seasons from wild and nursery plants. The antifungal activity of its leaves aqueous extracts (AE) was tested against six phytopathogenic fungi through a dilution method, including four AE. The antifungal activity against Colletotrichum gloeosporioides of the AE of the dry season from wild and nursery plants was similar and higher than those of the rainy season. A liquid-liquid partition chromatographic technique was used to obtain organic fractions. The hexane fraction (HF) of wild and nursery plants of the dry season inhibited the germination of C. gloeosporioides and C. truncatum (Syn. C. capsici) spores. The chromatographic analysis of AE from the wild plant of the dry season indicated that the abundance of metabolites was the highest. The bioautography showed that in both fungi the most active zone corresponds to the HF of the nursery plants. [ABSTRACT FROM AUTHOR]

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Induction of defense response in host plants by the Trichoderma spp. has been attributed as one of the major mechanisms leading to inhibition of the pathogenic ingression. The present study sheds light on the mechanisms employed by the Trichoderma isolates, obtained from phyllosphere (BHUF4) and rhizosphere (T16A), to modulate the defense network of chili plant under Colletotrichum truncatum challenge. Plants treated with both the Trichoderma strains exhibited significant accumulation of phenols under C. truncatum challenge with maximum increment recorded for capsaicin (16.1-fold), ferulic acid (5.03-fold), quercetin (5.36-fold), salicylic acid (94.88-fold), and kaempeferol (6.22-fold). Phenol accumulation corresponded to the subsequent defense gene expression pattern. When compared to the pathogen-challenged control plants, enhanced expression of PR1, PIK1, CHI, GLU, Cdef, and SAR genes was recorded in the Trichoderma-treated plants acting as a biocontrol agent (BCA). The results of the present study suggest that to strengthen the defense pathways in the host plant, the mechanisms employed by Trichoderma isolates differ and depend upon their origin and site of application. While phyllospheric Trichoderma isolate (BHUF4) employed the systemic acquired resistance (SAR) pathway, the rhizospheric Trichoderma strain (T16A) used the induced systemic response (ISR) pathway for eliciting the defense response in the host plant under C. truncatum challenge. The study signifies how Trichoderma strains obtained from different origin and when applied at different sites in plant judiciously reprogram the defense network of the host plant to provide robust protection against phytopathogens. In the present case, overall protection is provided to the chili plants against the foliar or underground attack of C. truncatum. [ABSTRACT FROM AUTHOR]

Fungal diseases lead to significant losses in soybean yields and a decline in seed quality; such is the case of the Asian soybean rust and anthracnose caused by Phakopsora pachyrhizi and Colletotrichum truncatum , respectively. Currently, the development of transgenic plants carrying antifungal defensins offers an alternative for plant protection against pathogens. This paper shows the production of transgenic soybean plants expressing the NmDef02 defensin gene using the biolistic delivery system, in an attempt to improve resistance against diseases and reduce the need for chemicals. Transgenic lines were assessed in field conditions under the natural infections of P. pachyrhizi and C. truncatum. The constitutive expression of the NmDef02 gene in transgenic soybean plants was shown to enhance resistance against these important plant pathogens. The quantification of the P. pachyrhizi biomass in infected soybean leaves revealed significant differences between transgenic lines and the non-transgenic control. In certain transgenic lines there was a strong reduction of fungal biomass, revealing a less severe disease. Integration and expression of the transgenes were confirmed by PCR, Southern blot, and qRT-PCR, where the Def1 line showed a higher relative expression of defensin. It was also found that the expression of the NmDef02 defensin gene in plants of the Def1 line did not have a negative effect on the nodulation induced by Bradyrhizobium japonicum. These results indicate that transgenic soybean plants expressing the NmDef02 defensin gene have a substantially enhanced resistance to economically important diseases, providing a sound environmental approach for decreasing yield losses and lowering the burden of chemicals in agriculture. [ABSTRACT FROM AUTHOR]

A loss of fungicide efficacy, particularly for carbendazim, was noted in soybean fields in Thailand and was considered to be due to the development of Colletotrichum truncatum resistance. The carbendazim sensitivity of C. truncatum populations isolated from various soybean fields in Thailand was thus evaluated with in vitro sensitivity assays and molecular characterization of mutations in the sequences of the ß2‐tubulin (TUB2) gene that confer carbendazim resistance in the pathogen. Among 52 isolates, 46 isolates were classified as highly resistant (HR) to carbendazim (EC50 > 1,000 µg/ml). All HR isolates grew on PDA amended with carbendazim at 1,000 µg/ml. Six isolates were classified as carbendazim sensitive (S) (EC50 < 1 µg/ml). Mycelial growth on PDA amended with 1 µg/ml carbendazim was inhibited by over 50% compared with growth on PDA alone. When a partial TUB2 gene from the isolates was amplified and analysed using predicted amino acid sequences, an alteration from glutamic acid to alanine at codon 198 (E198A) was found in 45 HR isolates for which the EC50 was higher than 2000 µg/ml. This mutation resulted from a nucleotide substitution from adenine to cytosine (GAG → GCG). The other HR isolate, CtPhS_1, with EC50 of 1,127 µg/ml, had an alteration at codon 200 (F200Y) (TTC → TAC). [ABSTRACT FROM AUTHOR]

Summary: Background: Colletotrichum is a rare cause of human infection. Previous reports about Colletotrichum keratitis were limited, and most diagnoses from past reports were based on morphological distinction, which could have led to underestimation of the prevalence of Colletotrichum species. Objective: We reported phylogenetic analysis, clinical feature and treatment outcome of molecularly diagnosed Colletotrichum keratitis in our hospital. Patients/Methods: We recruited 65 patients with culture‐proven filamentous fungal keratitis between January 1, 2015 and December 30, 2018. Through molecular sequencing including internal transcribed spacer (ITS) and multi‐locus phylogenetic analysis of fungal DNA, seven patients were verified as infected with Colletotrichum species, and their medical records were reviewed to determine the clinical characteristics. Results: Six of seven patients had predisposing factors including trauma (5) and immunosuppressive status (1). Six isolates were initially misidentified as other fungi through morphological identification. ITS sequencing identified the isolates belonged to two species complex (SC): C. truncatum and C. gloeosporioides; multi‐locus phylogenetic analysis enabled species identification including C. tropicale (3), C. fructicola (2), C. truncatum (1) and C. fusiforme (1). Five patients with C. gloeosporioides SC responded well to medical treatment and two patients with C truncatum SC underwent evisceration because of either no visual potential or intractable pain. Conclusions: The molecular approach provides accurate diagnosis and raises epidemiological awareness of Colletotrichum keratitis. Through multi‐locus phylogenetic analysis, we report the human infections caused by C. tropicale, C. fructicola and C. fusiforme. We also highlight the different clinical outcomes between C. gloeosporioides SC and C. truncatum SC. [ABSTRACT FROM AUTHOR]

Egusi melon (Citrullus lanatus (Thumb) Mansf.) is an important vegetable crop grown for edible seeds and oil in West Africa. Leaf Blight Disease (LBD) is one of the major constraints to its production, with potential to cause economic damage. The objective of this study was to investigate the incidence and distribution of leaf blight on Egusi melon in Southwestern Nigeria. A survey of LBD of Egusi melon was conducted in 2015 and 2016, in five southwestern States of Nigeria (Ogun, Oyo, Osun, Ekiti and Ondo States). Twenty plants each, were randomly sampled from 150 farms comprising 30 farms each, from each State. The distribution of different Egusi melon varieties planted was recorded. "Bara" cv. was the most cultivated variety (51.6%); followed by "Bojuri" (30.4%) and "Serewe" (18%). Leaf blight was observed in most farms in the five States, from 73% in Osun and Oyo states to 83% in Ondo State. Disease incidence and severity varied with locations and cultivars, and ranged from 0.0-87.5±18% and 1.0±0-4.5±0.8 in Osun State to 20.0±19 - 95.0±4.5% and 2.3±1.5 - 5.0±0 in Ondo State. Out of the twelve fungal pathogens from ten genera isolated from infected plants, only Colletotrichum truncatum, C. gloeosporioides and Lasiodiplodia theobromae caused Leaf blight on Egusi melon. [ABSTRACT FROM AUTHOR]

Colletotrichum is one of the most important plant pathogenic genus of fungi due to its scientific and economic impact. A wide range of hosts can be infected by Colletotrichum spp., which causes losses in crops of major importance worldwide, such as soybean. Soybean anthracnose is mainly caused by C. truncatum, but other species have been identified at an increasing rate during the last decade, becoming one of the most important limiting factors to soybean production in several regions. To gain a better understanding of the evolutionary origin of soybean anthracnose, we compared the repertoire of effector candidates of four Colletotrichum species pathogenic to soybean and eight species not pathogenic. Our results show that the four species infecting soybean belong to two lineages and do not share any effector candidates. These results strongly suggest that two Colletotrichum lineages have acquired the capability to infect soybean independently. This study also provides, for each lineage, a set of candidate effectors encoding genes that may have important roles in pathogenicity towards soybean offering a new resource useful for further research on soybean anthracnose management.