Colletotrichum
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Gene/QTL discovery for Anthracnose in common bean (Phaseolus vulgaris L.) from North-western Himalayas

Gene/QTL discovery for Anthracnose in common bean (Phaseolus vulgaris L.) from North-western Himalayas | Colletotrichum | Scoop.it
Abstract

Common bean (Phaseolus vulgaris L.) is one of the most important grain legume crops in the world. The beans grown in north-western Himalayas possess huge diversity for seed color, shape and size but are mostly susceptible to Anthracnose disease caused by seed born fungus Colletotrichum lindemuthianum. Dozens of QTLs/genes have been already identified for this disease in common bean world-wide. However, this is the first report of gene/QTL discovery for Anthracnose using bean germplasm from north-western Himalayas of state Jammu & Kashmir, India. A core set of 96 bean lines comprising 54 indigenous local landraces from 11 hot-spots and 42 exotic lines from 10 different countries were phenotyped at two locations (SKUAST-Jammu and Bhaderwah, Jammu) for Anthracnose resistance. The core set was also genotyped with genome-wide (91) random and trait linked SSR markers. The study of marker-trait associations (MTAs) led to the identification of 10 QTLs/genes for Anthracnose resistance. Among the 10 QTLs/genes identified, two MTAs are stable (BM45 & BM211), two MTAs (PVctt1 & BM211) are major explaining more than 20% phenotypic variation for Anthracnose and one MTA (BM211) is both stable and major. Six (06) genomic regions are reported for the first time, while as four (04) genomic regions validated the already known QTL/gene regions/clusters for Anthracnose. The major, stable and validated markers reported during the present study associated with Anthracnose resistance will prove useful in common bean molecular breeding programs aimed at enhancing Anthracnose resistance of local bean landraces grown in north-western Himalayas of state Jammu and Kashmir.
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Colletotrichum
All about the anthracnose fungus, plant pathogen, fungus pathogen, plant microbe interactions, plant disease, evolution, genomics
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Identification of a strawberry NPR-like gene involved in negative regulation of the salicylic acid-mediated defense pathway

Identification of a strawberry NPR-like gene involved in negative regulation of the salicylic acid-mediated defense pathway | Colletotrichum | Scoop.it
Abstract

Hormonal modulation plays a central role in triggering various resistant responses to biotic and abiotic stresses in plants. In cultivated strawberry (Fragaria x ananassa), the salicylic acid (SA)-dependent defense pathway has been associated with resistance to Colletotrichum spp. and the other pathogens. To better understand the SA-mediated defense mechanisms in strawberry, we analyzed two strawberry cultivars treated with SA for their resistance to anthracnose and gene expression profiles at 6, 12, 24, and 48 hr post-treatment. Strawberry genes related to SA biosynthesis, perception, and signaling were identified from SA-responsive transcriptomes of the two cultivars, and the induction of 17 candidate genes upon SA treatment was confirmed by qRT-PCR. Given the pivotal role of the non-expressor of pathogenesis-related (NPR) family in controlling the SA-mediated defense signaling pathway, we then analyzed NPR orthologous genes in strawberry. From the expression profile, FaNPRL-1 [ortholog of FvNPRL-1 (gene20070 in F. vesca)] was identified as an NPR-like gene significantly induced after SA treatment in both cultivars. With a conserved BTB/POZ domain, ankyrin repeat domain, and nuclear localization signal, FvNPRL-1 was found phylogenetically closer to NPR3/NPR4 than NPR1 in Arabidopsis. Ectopic expression of FvNPRL-1 in the Arabidopsis thaliana wild type suppressed the SA-mediated PR1 expression and the resistance to Pseudomonas syringae pv. tomato DC3000. Transient expression of FvNPRL-1 fused with green fluorescent protein in Arabidopsis protoplasts showed that SA affected nuclear translocation of FvNPRL-1. FvNPRL-1 likely functions similar to Arabidopsis NPR3/NPR4 as a negative regulator of the SA-mediated defense.
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Detection of latent infections caused by Colletotrichum sp. in olive fruit 


Aims

To set up a practical method to detect latent infections of Colletotrichum sp., the causal agent of olive anthracnose, on olives before the onset of disease symptoms.

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Fungicidal activities of camptothecin semisynthetic derivatives against Colletotrichum gloeosporioides in vitro and in mango fruit 

Fungicidal activities of camptothecin semisynthetic derivatives against Colletotrichum gloeosporioides in vitro and in mango fruit  | Colletotrichum | Scoop.it
Increasing attention to the resistance of plant pathogenic fungi to fungicides and their residues impels the development of more efficient fungicides …
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Aggressiveness profiling of the coffee pathogen Colletotrichum kahawae 

olletotrichum kahawae is a specialized plant pathogen of Arabica coffee in Africa, able to infect green berries. The economic impact of this pathogen leads to the urgent need of better understanding its pathogenic lifestyle, namely aggressiveness. In this study, several quantitative traits including disease severity, latent period and incubation period were measured to concomitantly assess the aggressiveness of 26 C. kahawae isolates. Our results show that the area under disease progression curve is the most informative variable, particularly when joined together with the index disease intensity 10 days after inoculation and latency period, while the incubation period is not a reliable trait to distinguish aggressiveness levels in C. kahawae. This study also confirms the suitability of hypocotyls and detached green berries to perform C. kahawae aggressiveness assays, revealing that hypocotyls are a more reproducible testing material. Based on the isolates’ profile, three aggressiveness classes were established (high, moderate and low). A cytological analysis of representative isolates from each class showed that aggressiveness can be related to the development of post‐penetration stages, rather than conidia germination and appressoria differentiation. This study provides, for the first time, the best metrics to evaluate C. kahawae aggressiveness, characterizing the profile of a broad range of isolates, and defining a set of parameters that can be used to classify new isolates. Furthermore, the collected information will contribute to improve coffee breeding programs, through the selection of tester isolates for pre‐screening of resistant coffee materials and offers the opportunity to engage on future genotype‐phenotype studies
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A Cdc42 homolog in Colletotrichum gloeosporioides regulates morphological development and is required for ROS-mediated plant infection

bstract
The Rho GTPase Cdc42 is conserved in fungi and plays a key role in regulating polarity establishment, morphogenesis and differentiation. In this study, we identified an ortholog of Cdc42, CgCdc42, and functionally characterized it to determine the role of Cdc42 in the development and pathogenicity of Colletotrichum gloeosporioides, a causal agent of poplar anthracnose. Targeted deletion of CgCdc42 resulted in reduced vegetative growth and dramatic morphological defects, including the formation of elongated conidia and abnormally shaped appressoria. Moreover, CgCdc42 deletion mutants were less virulent on poplar leaves than were wild type. Appressoria formed by ΔCgCdc42 mutants were morphologically abnormal and present in lower numbers on poplar leaves than were those formed by wild type. However, an ROS scavenging assay indicated that the ΔCgCdc42 mutants maintained wild type pathogenicity in the absence of ROS despite having fewer appressoria than wild type, suggesting that the ΔCgCdc42 mutants were deficient in their tolerance of ROS. Additionally, we also found that the distribution of ROS was different after the deletion of CgCdc42, the ΔCgCdc42 mutants were hypersensitive to H2O2, and transcriptional analysis revealed that CgCdc42 is involved in the regulation of ROS-related genes. Furthermore, loss of CgCdc42 caused defects in cell wall integrity and an uneven distribution of chitin. These data collectively suggest that CgCdc42 plays an important role in the regulation of vegetative growth, morphological development, cell wall integrity and ROS-mediated plant infection in C. gloeosporioides.

Keywords

Colletotrichum gloeosporioides Rho GTPase Cell wall integrity Morphogenesis Pathogenicity ROS 
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Postharvest anthracnose on Satsuma mandarin orange caused by Colletotrichum fioriniae

Abstract
In early January 2015–2017, anthracnose was detected on Satsuma mandarin orange (SMO) (Citrus unshiu) fruits kept in farmers’ storage rooms in Saga Prefecture, Japan. Three single-spore isolates from rotten fruits reproduced the postharvest anthracnose symptoms in wound-inoculated SMO fruits and were re-isolated from lesions. The isolates were identified as Colletotrichum fioriniae based on conidial morphology, culture characteristics, rDNA-ITS, and beta-tubulin-2 gene sequences. This is the first report of postharvest anthracnose on SMO caused by C. fioriniae.
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Pleiotropic Roles of ChSat4 in Asexual Development, Cell Wall Integrity Maintenance, and Pathogenicity in Colletotrichum higginsianum 

Potassium has important roles in multiple cellular processes. In Saccharomyces cerevisiae, the serine/threonine (S/T) kinase Sat4/Hal4 is required for potassium accumulation, and regulates the resistance to sodium salts, and stabilization of other plasma membrane transporters. However, the functions of Sat4 in filamentous phytopathogenic fungi are largely unknown. In this study, ChSat4, the yeast Sat4p homolog in Colletotrichum higginsianum, was identified. Target deletion of ChSat4 resulted in defects in mycelial growth and conidiation. Intracellular K+ accumulation was significantly decreased in the ChSat4 deletion mutant. Additionally, the ΔChSat4 mutant showed defects in cell wall integrity, hyperoxide stress response, and pathogenicity. Localization pattern analysis indicated ChSAT4 was localized in the cytoplasm. Furthermore, ChSAT4 showed high functional conservation with the homolog FgSAT4 in Fusarium graminearum. Taken together, our data indicates that ChSat4 is important for intracellular K+ accumulation and infection morphogenesis in C. higginsianum.
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Inhibition in production of cellulolytic and pectinolytic enzymes of Colletotrichum gloeosporioides isolated from dragon fruit plants in response to submicron chitosan dispersions 

Inhibition in production of cellulolytic and pectinolytic enzymes of Colletotrichum gloeosporioides isolated from dragon fruit plants in response to submicron chitosan dispersions  | Colletotrichum | Scoop.it
Abstract
In vitro and in vivo antifungal potential of submicron chitosan dispersions (SCD) was studied in order to investigate the effect of SCD on cell wall degrading enzymes of Colletotrichum gloeosporioides and to control anthracnose of dragon fruit under field conditions. Four concentrations of chitosan (0.5, 1.0, 1.5 and 2.0%) were used to prepare submicron dispersions with droplet sizes of 200, 400, 600, 800 and 1000 nm. The highest inhibition in cellulolytic and pectinolytic enzymes was observed with 600 nm droplet size of 1.0% chitosan concentration. In case of in vivo studies,the area under disease progress curve (AUDPC) showed a reduction of approximately 66% of disease incidence (DI). The lower level of production of cell wall degrading enzymes in response to SCD resulted in less disease on dragon fruit plants and sustained in increasing the effective resistance against the irresistible disease of anthracnose
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Colletotrichum tropicale causal agent of anthracnose on noni plants (Morinda citrifolia) in Guerrero, Mexico

Colletotrichum tropicale causal agent of anthracnose on noni plants (Morinda citrifolia) in Guerrero, Mexico | Colletotrichum | Scoop.it

During sampling in March 2014 severe anthracnose symptoms were observed, mainly in foliage, on noni plants (Morinda citrifolia) in Cocula, State of Guerrero, Mexico. Fungal monosporic colonies were isolated from leaves with anthracnose symptoms. The morphological characteristics matched those of conidia of Colletotrichum tropicale. DNA analysis was performed on mycelium of the fungus by PCR amplification of ITS sequences. The identification and pathogenicity of isolates was confirmed by inoculation of the pathogen onto healthy plants free from disease. Control plants remained healthy, while those inoculated with the pathogen developed lesions and symptoms of rot anthracnose eight days after inoculation. The morphological, molecular characteristics and pathogenicity tests of the isolates confirmed that C. tropicale is the causal agent of anthracnose in M. citrifolia.

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Acetyl‐coenzyme A synthetase gene ChAcs1 is essential in lipid metabolism, carbon utilization and virulence of the hemibiotrophic fungus Colletotrichum higginsianum 

Summary
Acetyl‐coenzyme A (acetyl‐CoA) is a key molecule that participates in many biochemical reactions in amino acid, protein, carbohydrate and lipid metabolism. Here, we genetically dissected distinct roles of two acetyl‐CoA synthetase genes, ChAcs1 and ChAcs2, in regulation of fermentation, lipid metabolism and virulence of the hemibiotrophic fungus Colletotrichum higginsianum. ChAcs1 and ChAcs2 are both highly expressed during appressorial development and primary hyphae formation stages and constitutively expressed in the cytoplasm throughout development stages. We found that C. higginsianum strains without ChAcs1 were non‐viable in the presence of most non‐fermentable carbon sources, including acetate, ethanol and acetaldehyde. Deletion of ChAcs1 also led to a decrease in lipid content of mycelia and delayed lipid mobilization in conidia to developing appressoria, which suggested that ChAcs1 can contribute to lipid metabolism in C. higginsianum. Furthermore, a ChAcs1 deletion mutant was defective in the switch to invasive growth, which may have been directly responsible for its reduced virulence. Transcriptomic analysis and qRT‐PCR revealed that ChAcs1 can affect the expression of genes involved in virulence and carbon metabolism, and that plant defense genes were up‐regulated, all demonstrated during infection by a ChAcs1 deletion mutant. In contrast, deletion of ChAcs2 only conferred slight delay of lipid mobilization, although it was highly expressed in infection stages. Our studies provide evidence for ChAcs1 as a key regulator governing lipid metabolism, carbon source utilization and virulence of this hemibiotrophic fungus.

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Top dieback in corn: Is this anthracnose or not?

Top dieback in corn: Is this anthracnose or not? | Colletotrichum | Scoop.it

Top dieback in corn: Is this anthracnose or not?

The dark green fields that were throughout SW Iowa and NW Missouri this summer are very quickly turning brown indicating the end to another growing season.  While this color change is not unusual. What is of concern is just how quickly it is occurring.

So, to look for Anthracnose stalk rot (ASR) we need to take a step back into the growing season. First, we need to check the distribution in the field. It is rare for a disease to infect an entire field.  Symptoms of top dieback occur on random plants. Secondly, we need to peel back the leaf sheath at the top of the affected area and look for black anthracnose lesions. If you see a pink jellylike substance on the stalk. it is likely to be anthracnose. If you split the stalk the pith will appear rotted or discolored in the upper internodes.

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Colletotrichum acutatum and C. gloeosporioides species complexes associated with apple in Brazil 

Glomerella leaf spot (GLS) is an apple disease that concern growers due to the increases in severity over the years and the difficulties in control. Species within the Colletotrichum acutatum and C. gloeosporioides species complexes cause GLS, but the proportion of species within each complex in Brazilian apple orchards are not known. The objectives of this study were to identify isolates of Colletotrichum causing GLS on apple orchards in the main Brazilian producing regions to the species level. Two hundred and seven isolates were obtained in orchards in São Paulo (SP), Parana (PR), Santa Catarina (SC) and Rio Grande do Sul (RS) states. Genomic DNA was extracted and the ITS, GAPDH, CHS-1 and TUB2 genes were amplified and sequenced. The phylogenetic trees were generated using a concatenated alignment. One hundred and fourteen isolates were identified as belonging to the C. acutatum species complex (Cac) and 93 to the C. gloeosporioides species complex (Cgc). Five phylogenetic species were identified: C. melonis (1.9%), C. nymphaeae (47.4%), C. paranaense (2.4%), C. limetticola (3.4%), and C. fructicola (44.9%). In SC, Cgc predominates, but in the states of SP, PR and RS, Cac was predominant. This is the first report of C. limetticola from apple.
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Genetic map‐guided genome assembly reveals a virulence‐governing minichromosome in the lentil anthracnose pathogen Colletotrichum lentis 

Summary
Colletotrichum lentis causes anthracnose, which is a serious disease on lentil and can account for up to 70% crop loss. Two pathogenic races, 0 and 1, have been described in the C. lentis population from lentil.
To unravel the genetic control of virulence, an isolate of the virulent race 0 was sequenced at 1481‐fold genomic coverage. The 56.10‐Mb genome assembly consists of 50 scaffolds with N50 scaffold length of 4.89 Mb. A total of 11 436 protein‐coding gene models was predicted in the genome with 237 coding candidate effectors, 43 secondary metabolite biosynthetic enzymes and 229 carbohydrate‐active enzymes (CAZymes), suggesting a contraction of the virulence gene repertoire in C. lentis.
Scaffolds were assigned to 10 core and two minichromosomes using a population (race 0 × race 1, n = 94 progeny isolates) sequencing‐based, high‐density (14 312 single nucleotide polymorphisms) genetic map. Composite interval mapping revealed a single quantitative trait locus (QTL), qClVIR‐11, located on minichromosome 11, explaining 85% of the variability in virulence of the C. lentis population. The QTL covers a physical distance of 0.84 Mb with 98 genes, including seven candidate effector and two secondary metabolite genes.
Taken together, the study provides genetic and physical evidence for the existence of a minichromosome controlling the C. lentis virulence on lentil.
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Responses of Johnsongrass Against Sorghum Anthracnose Isolates

Responses of Johnsongrass Against Sorghum Anthracnose Isolates | Colletotrichum | Scoop.it
Abstract
Johnsongrass is a creeping perennial weed that interferes with crop productivity. Due to genetic similarity to sorghum, Johnsongrass is considered to have potential as an alternate source of pathogen resistance genes for sorghum. In order to test this hypothesis, sorghum isolates of anthracnose (Colletotrichum sublineolum) were inoculated onto twenty-six Johnsongrass cultivars collected from across the southern US by using an excised leaf method. Upon inoculation with a C. sublineolum sorghum isolate, different Johnsongrass cultivars showed different degrees of infection. Moreover, three different C. sublineolum isolates caused different responses on the same Johnsongrass cultivar. Expression of early defense response related genes, including β-1,3-glucanase, chalcone synthase 8 (CHS8), pathogen induced chitinase, flavonoid-3’-hydroxylase, pathogenesis related protein-10 (PR- 10), and thaumatin-like protein, were measured 24 hrs and 48 hrs post inoculation in selected Johnsongrass cultivars by Real-Time qRT-PCR. The results revealed that levels of defense responses varied among cultivars but were not sufficient to establish a basis for resistance. When the same Johnsongrass cultivars were inoculated in a greenhouse study with conidia of Colletotrichum sublineolum isolate FSP53 from sorghum, some showed evidence of a hypersensitive response. However, successful reproduction of the pathogen as detected by formation of acervuli and setae was seen only on SH1116 and on only one leaf of this cultivar.

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Corn Stalk Rot - Tamra Jackson-Ziems -

Nebraska Extension Plant Pathologist Tamra Jackson-Ziems explains stalk rot in corn, how to identify it, and what farmers can do if it’s already present in t...
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A Clade II‐D Fungal Chimeric Diterpene Synthase from Colletotrichum gloeosporioides Making Dolasta‐1(15),8‐dien

Based on a terpenoid overproduction platform in yeast for genome mining, a chimeric diterpene synthase from the endophytic fungus Colletotrichum gloeosporioides ES026 was characterized as (5R,12R,14S)‐dolasta‐1(15),8‐diene synthase. The absolute configuration was independently verified by use of enantioselectively deuterated terpene precursors which unequivocally established the predicted C1‐III‐IV cyclization mode for this first characterized clade II‐D enzyme. Extensive isotopic labeling experiments and isolation of the intermediate (1R)‐δ‐araneosene supported the proposed cyclization mechanism.
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A halotolerant bifunctional β-xylosidase/α-l-arabinofuranosidase from Colletotrichum graminicola: Purification and biochemical characterization - ScienceDirect

A halotolerant bifunctional β-xylosidase/α-l-arabinofuranosidase from Colletotrichum graminicola: Purification and biochemical characterization - ScienceDirect | Colletotrichum | Scoop.it
Abstract
A β-xylosidase from Colletotrichum graminicola (Bxcg) was purified. The enzyme showed high halotolerance, retaining about 63% of the control activity in the presence of 2.5 mol L−1 NaCl. The presence of NaCl has not affected the optimum reaction temperature (65 °C), but the optimum pH was slightly altered (from 4.5 to 5.0) at high salt concentrations. Bxcg was fully stable at 50 °C for 24 h and over a wide pH range even in the presence of NaCl. In the absence of salt Bxcg hydrolyzed p-nitrophenyl-β-d-xylopyranoside with maximum velocity of 348.8 ± 11.5 U mg−1 and high catalytic efficiency (1432.7 ± 47.3 L mmol−1 s−1). Bxcg revealed to be a bifunctional enzyme with both β-xylosidase and α-l-arabinofuranosidase activities, and hydrolyzed xylooligosaccharides containing up to six pentose residues. The enzyme showed high synergistic effect (3.1-fold) with an endo-xylanase for the hydrolysis of beechwood xylan, either in the absence or presence of 0.5 mol L−1 NaCl, and was tolerant to different organic solvents and surfactants. This is the first report of a halotolerant bifunctional β-xylosidase/α-l-arabinofuranosidase from C. graminicola, and the enzyme showed attractive properties for application in lignocellulose hydrolysis, particularly under high salinity and/or in the presence of residues of pretreatment steps.

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The current status on secondary metabolites produced by plant pathogenic Colletotrichum species

Abstract
The fungal genus Colletotrichum contains about 190 species, many of which are responsible for serious plant diseases including those of commercial crops. These species infect a wide range of crops in the tropical, sub-tropical and temperate regions of the world. The diseases caused by Colletotrichum species are known as “anthracnose diseases” and are characterized by sunken necrotic tissue in which masses of orange conidia are produced. A significant number of the metabolites of Colletotrichum species are known to contribute to their pathogenicity. These phytotoxic metabolites when applied to the leaves of their host plants, induced symptoms which were similar to those of the anthracnose caused by the fungus. These metabolites have been shown to play a significant role in the mechanism of infection and pathogenesis. This review deals with the structures and biological activity of the secondary metabolites which have been isolated from these economically important filamentous fungi. The literature up to July 2018 is reviewed and 160 references are cited.

Keywords

Anthracnose Biological activity Fungus Pathogenicity Phytopathogen 
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Anthracnose of Cow pea –

Anthracnose of Cow pea – | Colletotrichum | Scoop.it
Stored dried pods of cowpea pods got infected and we observed black spots all over the pods. Fig: Infected cow pea pods It may be Anthracnose.Anthracnose is mainly a seed-borne disease caused by a…...
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Microsatellite mining in the genus Colletotrichum - 

Microsatellite mining in the genus Colletotrichum -  | Colletotrichum | Scoop.it
Highlights

We mined microsatellites from eight Colletotrichum genomes belonging to six clades for the first time


Using bioinformatics pipeline, we developed 57, 170 microsatellite markers and ninety-nine percent of the microsatellites primers produced a single product in an electronic PCR


In vitro amplification confirmed the locus specific amplification and present study is the first of its kind where microsatellite markers were used to deduce the diversity of bean anthracnose pathogen.


The microsatellites markers developed will provide a useful tool to discover the population structure in different Colletotrichum species
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RNA-mediated silencing of PKS1 gene in Colletotrichum falcatum causing red rot in sugarcane

Abstract
Red rot is one of the major threatening diseases of sugarcane. Due to frequent breakdown of resistance by simultaneous evolution of pathogen variants with the introduction of newer varieties red rot remains as a challenge for successful breeding programme in India. Earlier studies established that the pathogen has limited genotypic variation with enormous phenotypic variation, which could be mainly due to adaptability of pathogen to the newly released varieties and expression of pathogenicity factors including secondary metabolites viz., toxins, enzymes and pigments like melanin. It is also proved that a positive correlation remains between the production of melanin and disease expression and hence the melanin biosynthesizing genes viz., Polyketide synthase1 (PKS1), Scytalone dehydratase1 (SCD1) and Trihydroxynapthalene reductase1 (THR1) were characterized. In this study, we have utilized RNA interference (RNAi) approach using pSilent-1 vector which facilitates the generation of hair pin constructs that suppress the expression of target gene through Agrobacterium mediated transformation (ATMT) to functionally analyze the major gene PKS1 involved in the production of dihydroxy naphthalene (DHN) melanin to determine its role in virulence in C. falcatum. Functionally active sites of the PKS1 gene i.e., acyl transferase (AT) domain and the region responsible for conidial pigment (CP) polyketide synthase were chosen for knockdown approach. The above said regions were amplified in the virulent C. falcatum isolate (Cf671) and both the sense and antisense fragments were separately cloned into pSilent-1 vector. The expression cassette was then cloned into the binary vector and introduced into Agrobacterium tumefaciens LBA4404 which was later co-cultivated with the fungal spore suspension. Results indicated that the knockdown AT mutant failed to produce spores whereas the CP mutants produced spores as that of the parental strains. Further pathogenicity testing revealed that the disease symptoms of both AT and CP mutants were restricted within the inoculated internode until 15th and 5th dpi respectively while the symptoms of wild type were prominent and crossed beyond 3rd internode at 15 dpi during the host-pathogen interaction. Molecular confirmation of the knockdown mutants with the expression of hygromycin gene and absence of functional domains under RT-PCR clearly indicated that the PKS1 gene has a possible role in C. falcatum pathogenesis. However expression analysis by qRT-PCR indicated regaining of virulence in mutants during later part of host pathogen interaction. The results confirm the applicability of RNAi mediated silencing for functional analysis of pathogenicity gene homologs in C. falcatum.

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Efficacy of fungicides in managing anthracnose of strawberry 


Abstract
Strawberry anthracnose (Colletotrichum gloeosporioides (Penz.) Penz. et Sacc.) is a serious disease for its successful cultivation. The present investigation was carried out at PAU, Ludhiana during the year 2015–16 on the management of the disease with fungicides. Four systemic fungicides namely, propiconazole, carbendazim, azoxystrobin, thiophanate methyl and three non-systemic fungicides viz. mancozeb, copper oxychloride and ziram were evaluated in vitro and in vivo to test their efficacy against anthracnose of strawberry. Among the systemic fungicides, propiconazole was found significantly effective in inhibiting the mycelial growth of C. gloeosporioides with ED50 value of < 5 ppm under in vitro where as mancozeb among non-systemic fungicides, was significantly better than copper oxychloride and ziram in inhibiting the growth of pathogen. The ED50 value of mancozeb was < 25 ppm. The order of ranking of systemic fungicides against Colletotrichum gloeosporioides pathogen was propiconazole < carbendazim < thiophanate methyl

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Screening for Susceptibility to Anthracnose Stem Lesions in Southern Highbush Blueberry

Screening for Susceptibility to Anthracnose Stem Lesions in Southern Highbush Blueberry | Colletotrichum | Scoop.it
Flicker’ is a southern highbush blueberry (SHB, Vaccinium corymbosum) cultivar frequently selected by growers in Central and South Florida. In 2014, several growers in Central Florida experienced issues with anthracnose stem lesions and twig dieback on ‘Flicker’, resulting in a reduction in new plantings and the removal of many existing plantings. The objective of this study was to determine the level of anthracnose susceptibility of certain commercially available SHB cultivars, which information can be used to limit further use of susceptible cultivars in the University of Florida blueberry breeding program. The screening was performed using a spray inoculation of a virulent Colletotrichum gloeosporioides isolate onto whole V. corymbosum plants, followed by measurement of incidence and severity of disease over time. In repeated experiments, ‘Flicker’ and two other cultivars had a significantly higher mean number of lesions and area under the disease progress curve (AUDPC) than any other tested cultivar, and in both experiments, the observed lesions were similar in many respects to those previously reported on northern highbush blueberry (also V. corymbosum). Although the results of these experiments may ultimately indicate that Flicker has a unique genetic susceptibility to this form of anthracnose among SHB cultivars commercially grown in Florida, screening of additional cultivars must be performed for confirmation.
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In Vitro Evaluation of the Resistance of Seven Isolates of Colletotrichum acutatum to Thiram and Copper

In Vitro Evaluation of the Resistance of Seven Isolates of Colletotrichum acutatum to Thiram and Copper | Colletotrichum | Scoop.it
Abstract
Seven Isolates of Colletotrichum acutatum have been collected from strawberries attacked with anthracnose in the Loukous territory, Morocco. The study of the effect in vitro of 3 fungicides with Thiram as active substance and another one with copper on seven isolates of C. acutatum was studied. Thiram has a potent effectiveness on germination and is moderately effective on mycelial growth and sporulation. Copper has shown effectiveness on germination as variable activity in other strain’s life stage.
Keywords: Anthracnose, Strawberry, Colletotrichum acutatum, Loukous, Morocco, Fungicides, Thiram, Copper
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Anthracnose crown rot in putting greens, and the turf stress behind it | K-State Turfgrass

Anthracnose crown rot in putting greens, and the turf stress behind it | K-State Turfgrass | Colletotrichum | Scoop.it
(Megan Kennelly, KSU Plant Pathology) We had a sample come in with soggy roots, algae, and a lot of thinning. Here is the root zone. Lots of organ...
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