scholarly journals Conventional PCR for detection of Corynespora cassiicola in soybean seeds

2016 ◽  
Vol 38 (2) ◽  
pp. 85-91 ◽  
Author(s):  
Marcella Viana de Sousa ◽  
Carolina da Silva Siqueira ◽  
José da Cruz Machado
Keyword(s):  
Pure Culture ◽  
Early Stage ◽  
Soybean Seeds ◽  
Inoculum Potential ◽  
Corynespora Cassiicola ◽  
Severe Damage ◽  
Conventional Pcr ◽  
Seed Testing ◽  
Target Spot ◽  
Specificity And Sensitivity

Abstract The fungus Corynespora cassiicola, causal agent of target spot in soybeans, can be transmitted by soybean seeds and as of that point cause severe damage. This disease may be diagnosed at an early stage by seed testing, but knowledge in this area is insufficient. Because of that and increased attack by the disease in soybean areas in Brazil, further studies are required. The aim of this study was to evaluate the use of conventional PCR in detecting C. cassiicola in soybean seeds. The GA4-F/GA4-R primers described in the literature were tested for their specificity and sensitivity for detection of C. cassiicola in pure culture and in soybean seeds. Uninoculated and inoculated seed samples were used with different incidence levels - 100%, 10%, 1%, 0.5%, 0.25%, and 0% of preestablished inoculum potentials, P0, P1, P2, and P3. Detection of C. cassiicola in P1 inoculum potential was observed in samples with incidence levels of 10% to 100%. In the P3 potential, detection of the pathogen was successful in samples at the low level of 0.25%.

scholarly journals Corynespora cassiicola in soybean seeds – incidence and transmission

2020 ◽  
Vol 36 ◽  
Author(s):  
Augusto César Pereira Goulart ◽  
Carlos Mitinori Utiamada
Keyword(s):  
Seed Germination ◽  
Transmission Rate ◽  
Seedling Emergence ◽  
Point Of View ◽  
Soybean Seeds ◽  
Corynespora Cassiicola ◽  
Initial Development ◽  
Soybean Seedlings ◽  
Target Spot ◽  
Seed Pathology

The fungus Corynespora cassiicola, causal agent of target spot in soybeans, has been considered, from the seed pathology point of view, a seed-borne pathogen of limited importance. Therefore, little importance has been given to the role of the seeds in the transmission of this pathogen. The objectives of this study were to determine the incidence of C. cassiicola in soybean seeds and evaluate the effects of this seed-borne pathogen, inoculated in the seeds, in relation to physiological and epidemiological parameters. The experiments were carried out at TAGRO and Embrapa Western Agriculture under lab (blotter test and seed germination test) and greenhouse conditions (growing on test). The fungus C. cassiicola was detected in 11.3% of the 639 seed samples analyzed, with an average incidence of 0.91% and maximum of 8.5%. The transmission of C. cassiicola from the seeds to above-ground parts of soybean seedlings was demonstrated, by pathogen establishment on the cotyledon, showing circular lesions with concentric rings, reddish-brown in the center and surrounded by a yellowish green halo, as a typical symptoms of target spot. Reddish-brown lesions on the roots and stem of the seedlings were also observed. Considering a sample seed with 66.0% of C. cassiicola incidence, the symptomatic transmission based on cotyledon symptoms was 42.2%, corresponding to a transmission rate of 2.4:1. This is the first report, in a quantified way, about the transmission of C. cassiicola from the seeds to above-ground parts of soybean seedlings. When compared to non-inoculated seeds, seed germination, seedling emergence and seedling initial development were influenced by the presence of the pathogen in the seeds, with the lowest values being observed when the seeds were inoculated.

scholarly journals Specificity and sensitivity of three PCR-based methods for detection of Erwinia amylovora in pure culture and plant material

Genetika ◽  
2019 ◽  
Vol 51 (3) ◽  
pp. 1039-1052
Author(s):  
Milan Ivanovic ◽  
Nemanja Kuzmanovic ◽  
Katarina Gasic ◽  
Andjelka Prokic ◽  
Nevena Zlatkovic ◽  
...  
Keyword(s):  
Nested Pcr ◽  
Pure Culture ◽  
Plant Material ◽  
Erwinia Amylovora ◽  
Inhibitory Effect ◽  
Bacterial Cells ◽  
Conventional Pcr ◽  
Specificity And Sensitivity ◽  
Pure Cultures ◽  
Sensitivity Specificity

Three PCR methods, referred in this study as ?conventional?, ?nested? and ?chromosomal? PCR and suggested for routine detection of Erwinia amylovora in pure culture and plant material, were evaluated according to their specificity and sensitivity. Specificity of PCR methods was analyzed by using 42 strains of E. amylovora, originating from different locations and plant species, with diverse PFGE profiles, representing distant populations of the pathogen. Sensitivity of PCR protocols in pure culture was studied by using nine different concentrations of E. amylovora in sterile ultrapure water as a template in PCR reactions. In order to study inhibitory effect of plant DNA and other inhibitors on sensitivity of the three PCR methods bacterial dilutions were mixed with plant macerate of pear, apple and quince prior to the PCR reaction. In specificity assays, tested PCR protocols were able to detect all E. amylovora strains regardless of the host of the strain, its origin or PFGE group, indicating primer specificity. On the other hand, sensitivity among tested methods varied, depending on bacterial concentration and selected plant material used in the PCR. When working with pure cultures nested PCR showed the greatest sensitivity by detecting 1.9 bacterial cells per PCR reaction, followed by detection limit of 9.5 cells per PCR reaction with conventional PCR and 1.9?105 cells/PCR reaction with chromosomal PCR. In spiked samples plant inhibitors either did not affect or they decreased the sensitivity of the PCR reaction, depending on the protocol and/or type of plant macerate. In our experiments, inhibitors from pear and quince macerates did not affect sensitivity of nested PCR, while apple macerate reduced its sensitivity by a factor of 10. Conventional PCR protocol was able to detect 95 cells/PCR reaction in pear and apple macerate, but only 9.5?103 cells/PCR in quince macerate. Greatest decrease in sensitivity of the PCR method was observed in spiked samples with chromosomal PCR since bacterial DNA was not detected in each of the spiked samples. Our research shows that all three PCR protocols are specific for detection of E. amylovora, but nested PCR proved to be most sensitive when working with pure cultures and plant material.

scholarly journals First Report of Target Spot Caused by Corynespora cassiicola on Cotton in Georgia

Plant Disease ◽  
2012 ◽  
Vol 96 (7) ◽  
pp. 1066-1066 ◽  
Author(s):  
A. M. Fulmer ◽  
J. T. Walls ◽  
B. Dutta ◽  
V. Parkunan ◽  
J. Brock ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Leaf Spot ◽  
Pure Culture ◽  
Pathogenic Fungi ◽  
Fluorescent Light ◽  
Corynespora Cassiicola ◽  
Sterile Water ◽  
First Report ◽  
Target Spot ◽  
Initial Symptoms

In 2005, crop consultants in southwestern Georgia reported an unusual occurrence of leaf spot in cotton (Gossypium hirsutum L.). Initial symptoms first developed as brick red dots that led to the formation of irregular to circular lesions with tan-to-light brown centers. Lesions further enlarged and often demonstrated a targetlike appearance formed from concentric rings within the spot. Observations included estimates of premature defoliation up to 70%, abundant characteristic spots on the leaves and bracts, and losses of several hundred kg of lint/ha. When symptomatic leaves were submitted to the University of Georgia Tifton Plant Disease Clinic in Tifton, GA, for identification in 2008, the causal agent was tentatively diagnosed as Corynespora cassiicola (Berk. & M.A. Curtis) C.T. Wei on the basis of similar symptoms and signs previously reported on cotton (3). In September 2011, symptomatic leaves were obtained from diseased cotton within a field (var. DP 1048B2RF) near Attapulgus, GA. Symptomatic tissue from diseased leaves was surface disinfested in 0.5% sodium hypochlorite for 1 min and plated on potato dextrose agar (PDA). Ten isolates were incubated at 21.1°C for 2 weeks with a 12/12 h light/dark cycle using fluorescent light located approximately 70 cm above the cultures. After 1 week, two isolates were transferred to quarter strength PDA for enhanced sporulation and were grown under the same conditions. Conidiophores from the isolated fungus were simple, erect, intermittently branching and septate, and gave rise to single, subhyaline conidia. Conidia had 4 to 17 pseudosepta and were 50 to 197 μm long and 7 to 16 μm wide, straight to curved, and obclavate to cylindrical. Pathogenicity tests were conducted by spraying 10 cotton seedlings (DP 555BR and DP 1048B2RF, two to four true leaf stage) until runoff with a blended suspension from a 2-week-old pure culture of the fungus diluted with 100 mL of sterile water. Five plants were sprayed with sterile water as noninoculated controls. Cotton seedlings were then incubated in a moist chamber at 21.1°C for 48 h. Within 1 week, all inoculated plants showed symptoms similar to those of diseased field plants. Symptoms were not observed on noninoculated control plants. The fungus was reisolated five times from symptomatic leaves and grown in pure culture. Conidia and conidiophores were identical to the morphology of the original isolates, and were similar to descriptions of C. cassiicola (2). To confirm the identity of the pathogen, DNA was extracted from a week-old culture and amplified with specific primers for loci “ga4” and “rDNA ITS” (1). DNA sequences obtained with the Applied Biosystems 3730xl 96-capillary DNA Analyzer showed 99% identity to C. cassiicola from BLAST analysis in GenBank. The resulting sequence was deposited into GenBank (Accession No. JQ717069). To our knowledge, this is the first report of this pathogen in Georgia. Given the increasing prevalence of this disease in southwestern Georgia, its confirmation is a significant step toward management recommendations for growers. Because foliar diseases caused by C. cassiicola are commonly referred to as “target spot” in other crops (e.g., soybeans), it is proposed that Corynespora leaf spot of cotton be known as “target spot of cotton.” References: (1) L. J. Dixon et al. Phytopathology 99:1015, 2009. (2) M. B. Ellis and P. Holliday. CMI Description of Pathogenic Fungi and Bacteria, 303, 1971. (3) J. P. Jones. Phytopathology 51:305, 1961.

A Review of Corynespora cassiicola and Its Increasing Relevance to Tomato in Florida

2018 ◽  
Vol 19 (4) ◽  
pp. 303-309 ◽  
Author(s):  
Keevan J. MacKenzie ◽  
Leilani G. Sumabat ◽  
Katia V. Xavier ◽  
Gary E. Vallad
Keyword(s):  
Fungal Pathogen ◽  
Effective Control ◽  
Corynespora Cassiicola ◽  
Varietal Resistance ◽  
Vegetable Crop ◽  
Fresh Market ◽  
Resistance Development ◽  
Pathogen Diversity ◽  
Target Spot ◽  
Insight Into

Corynespora cassiicola is a highly diverse fungal pathogen that can infect more than 500 species of plants, including many economically important crops such as cotton, soybean, tomato, and cucumber. In Florida, the number one vegetable crop by market value are fresh-market tomatoes, which generate nearly half a billion dollars annually. Florida’s subtropical to tropical climate is conducive to infection and development of the target spot pathogen on tomato caused by C. cassiicola. There is no varietal resistance available for target spot of tomato, and preventative fungicide treatments are the primary method for control. In the last decade, C. cassiicola has been more frequently reported by Florida tomato growers, appearing not only more aggressive but also increasingly insensitive to various fungicides. This review brings together the most recent C. cassiicola literature, providing a history and understanding of the immense pathogen diversity and its relevance to tomato. It also provides insight into fungicide resistance development and pathogen survivability, which are important factors in providing effective control recommendations and in understanding the epidemiology of this disease, respectively.

scholarly journals Emerging Role of Inhibin as a Biomarker for Ovarian Cancer

2005 ◽  
Vol 1 (1) ◽  
pp. 51-57 ◽  
Author(s):  
David M Robertson ◽  
Martin K Oehler
Keyword(s):  
Ovarian Cancer ◽  
Granulosa Cell ◽  
Early Stage ◽  
Clinical Stage ◽  
Survival Rates ◽  
Ovarian Carcinomas ◽  
Gynecological Malignancy ◽  
Granulosa Cell Tumors ◽  
Ovarian Cancers ◽  
Specificity And Sensitivity

Ovarian cancer is the most lethal gynecological malignancy as it is diagnosed at a late clinical stage in more than 80% of patients. The development of diagnostic tests that can detect all types of ovarian cancers with high specificity and sensitivity, and at an early stage would improve survival rates. Serum inhibin is an ovarian hormone involved in the regulation of fertility, decreasing to undetectable levels after menopause. Certain ovarian malignancies, such as mucinous carcinomas and granulosa cell tumors, continue to produce inhibin, which is detectable in serum. A test for serum inhibin has been developed which is able to diagnose granulosa cell tumors and mucinous carcinomas with high accuracy. When the inhibin assay is used in conjunction with the CA125 test, which detects epithelial ovarian carcinomas, the two tests detect the majority of ovarian cancers with high sensitivity (95%) and specificity (95%). This article discusses the application of the inhibin test in ovarian cancer.

Validation of a high performing blood test for multiple major cancer screenings.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 10561-10561
Author(s):  
Linhao Xu ◽  
Jun Wang ◽  
Weifeng Ma ◽  
Xin Liu ◽  
Sihui Li ◽  
...  
Keyword(s):  
Cancer Screening ◽  
Blood Test ◽  
Retrospective Cohort ◽  
Early Stage ◽  
Stage I ◽  
Cancer Type ◽  
Data Set ◽  
Specificity And Sensitivity ◽  
Cancer Types ◽  
Stage Stage

10561 Background: Early detection at the localized stage is pivotal for the successful treatment of various cancer types. Although several cancers already have routine screening approaches, the comprehensive utilities are impeded for various reasons, e.g., low accuracy, high cost, limited availability of required facilities, especially in the developing countries. Therefore, an accurate, cost-effective, and non-invasive test for multiple major cancer screening is in high demand. We previously reported a cfDNA methylation test, which can detect five major cancer types with high specificity and sensitivity, especially at the early stage (stage I). These five major cancers, including lung cancer (LC), breast cancer (BC), colorectal cancer (CRC), gastric cancer (GC), and esophageal cancer (EC), account for 56% of new cancer cases and 60% of cancer-related deaths yearly in China. Here, we report the result in an independent cohort as a further validation of this multi-cancer screening test. Methods: The high-throughput targeted methylation profiling platform, Aurora, was used to analyze the plasma samples from an independent retrospective cohort containing 505 healthy controls and ̃200 cases for each cancer type. A locked model based on our previous pilot study (reported in AACR 2020 and 2021) was applied to this data set to assess the overall performance. Results: The Area Under Curves (AUC) of the classifier for LC, BC, CRC, GC and EC are 97.3%, 96.2%, 92.0%, 94.0% and 93.5%, respectively. At a fixed specificity of 99%, the sensitivities for LC, BC, CRC, GC and EC are 84%, 75%, 82%, 85% and 78%, respectively. Conclusions: A methylation blood test for five major cancer screening has been validated in a large retrospective cohort. Its high sensitivity for each cancer type, especially at the early stage (stage I), and easy to use suggests it can be implemented in real clinical world. A large prospective clinical trial is undergoing to further validate this test in asymptomatic populations.

scholarly journals The Use of Biomarkers in Early Diagnostics of Pancreatic Cancer

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Lumir Kunovsky ◽  
Pavla Tesarikova ◽  
Zdenek Kala ◽  
Radek Kroupa ◽  
Petr Kysela ◽  
...  
Keyword(s):  
Radical Surgery ◽  
Early Stage ◽  
Locally Advanced ◽  
High Specificity ◽  
Cost Effective ◽  
Ductal Adenocarcinoma ◽  
Specificity And Sensitivity ◽  
Solid Malignancies ◽  
Late Detection ◽  
Resistance To Chemotherapy

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal solid malignancies with increasing incidence. The poor prognosis is due to the aggressive nature of the tumor, late detection, and the resistance to chemotherapy and radiotherapy. A radical surgery procedure is the only treatment that has been shown to improve the 5-year survival rate to 20-25%. However, the majority of patients (80-85%) are diagnosed with locally advanced or metastatic disease and just 15-20% patients are diagnosed in an early stage allowing them to undergo the potentially curative surgical resection. The early detection of PDAC without the use of invasive methods is challenging and discovery of a cost-effective biomarker with high specificity and sensitivity could significantly improve the treatment and survival in these patients. In this review, we summarize current and newly examined biomarkers in early PDAC detection.

scholarly journals Widespread QoI Fungicide Resistance Revealed Among Corynespora cassiicola Tomato Isolates in Florida

Plant Disease ◽  
2020 ◽  
Vol 104 (3) ◽  
pp. 893-903 ◽  
Author(s):  
Keevan J. MacKenzie ◽  
Katia V. Xavier ◽  
Aimin Wen ◽  
Sujan Timilsina ◽  
Heather M. Adkison ◽  
...  
Keyword(s):  
Amino Acid Position ◽  
Rapid Screening ◽  
Silent Mutation ◽  
Screening Methods ◽  
Corynespora Cassiicola ◽  
Qoi Fungicides ◽  
Quinone Outside Inhibitor ◽  
Target Spot ◽  
Moderately Resistant ◽  
Qoi Resistance

Target spot of tomato caused by Corynespora cassiicola is one of the most economically destructive diseases of tomato in Florida. A collection of 123 isolates from eight counties in Florida were evaluated for sensitivity to azoxystrobin and fenamidone based on mycelial growth inhibition (MGI), spore germination (SG), detached leaflet assays (DLAs), and sequence-based analysis of the cytochrome b gene (cytb). Cleavage of cytb by restriction enzyme (Fnu4HI) revealed the presence of a mutation conferring a glycine (G) to alanine (A) mutation at amino acid position 143 (G143A) in approximately 90% of the population, correlating with quinone outside inhibitor (QoI) resistance based on MGI (<40% at 5 μg/ml), SG (<50% at 1 and 10 μg/ml), and DLA (<10% severity reduction). The mutation conferring a phenylalanine (F) to leucine (L) substitution at position 129 (F129L) was confirmed in moderately resistant isolates (#9, #19, and #74) based on MGI (40 to 50% at 5 μg/ml), SG (<50% at 1 μg/ml and >50% at 10 μg/ml), and DLA (>10% and <43% severity reduction) for both QoI fungicides, whereas sensitive isolates (#1, #4, #7, #28, #29, #46, #61, #74, #75, #76, #91, #95, and #118) based on MGI (>50% at 5 μg/ml), SG (>50% at 1 μg/ml and 10 μg/ml), and DLA (>50% severity reduction) correlated to non-mutation-containing isolates or those with a silent mutation. This study indicates that QoI resistance among C. cassiicola isolates from tomato is widespread in Florida and validates rapid screening methods using MGI or molecular assays to identify resistant isolates in future studies.

AN OVERVIEW OF TARGET SPOT OF TOMATO CAUSED BY CORYNESPORA CASSIICOLA

2009 ◽  
pp. 25-28 ◽  
Author(s):  
R.L. Schlub ◽  
L.J. Smith ◽  
L.E. Datnoff ◽  
K. Pernezny
Keyword(s):  
Corynespora Cassiicola ◽  
Target Spot
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