scholarly journals A Monocot Plant Identified as an Alternate Host of the Causal Agent of Bacterial Spot of Tomato and Pepper

HortScience ◽  
2002 ◽  
Vol 37 (6) ◽  
pp. 969-972 ◽  
Author(s):  
Harold A.A. Gibbs
Keyword(s):  
Xanthomonas Campestris ◽  
In Planta ◽  
Bacterial Spot ◽  
Alternate Host ◽  
Spot Disease ◽  
Commelina Benghalensis ◽  
Weed Growth ◽  
Bacterial Spot Disease ◽  
Stem Extract ◽  
Physiological Reactions

Xanthomonas campestris pv. vesicatoria (Xcv) recovered from Commelina benghalensis L., caused bacterial spot disease in cultivars of pepper and tomato susceptible to the pathogen. This is the first reported case of a dicot-infecting Xc pathovar infecting a monocot plant, represented here by a member of the Family Commelinaceae. Laboratory strains of the pathogen that included 81-23, 81-23M13, 82:4, 2595, and P6AD4, known to be pathogenic to pepper and tomato, promoted bacterial spot symptoms on leaves of C. benghalensis L. Of the 63 field isolates recovered from infected C. benghalensis L., 30 gave biochemical and physiological reactions consistent with Xcv pathogens, whereas 10 of the latter promoted bacterial spot disease in the test cultivars resulting in the identification of seven pathogenic races, including P2, P5, P6, P5T1, P5T2, P6T2, and P6T3. Bacterial spot disease symptoms developed on stems only when C. benghalensis L. was spray-inoculated with strains 81-23, 81-23M13, and P6AD4. Bacterial concentration increased in planta by as much as 103 per lesion of the leaf, whereas growth of the same strains was restricted in the stem of this weed. Growth of these three strains was, however, significantly (P ≤ 0.05) lower on NYGA amended with C. benghalensis L. stem extract than on NYGA amended with leaf extract. The ability of the bacterial spot pathogen to infect the stem of C. benghalensis L. has serious implications for management of bacterial spot disease in fields populated with this weed since stems of this plant infected with the pathogen continue to grow vegetatively and disperse throughout all fields in which it is found.

Effect of acidic electrolyzed water on the viability of bacterial and fungal plant pathogens and on bacterial spot disease of tomato

2006 ◽  
Vol 52 (10) ◽  
pp. 915-923 ◽  
Author(s):  
P A Abbasi ◽  
G Lazarovits
Keyword(s):  
Xanthomonas Campestris ◽  
Plant Pathogens ◽  
Disease Incidence ◽  
Bacterial Spot ◽  
Tomato Seed ◽  
Electrolyzed Water ◽  
Spot Disease ◽  
Foliar Sprays ◽  
Fungal Plant Pathogens ◽  
Bacterial Spot Disease

Acidic electrolyzed water (AEW), known to have germicidal activity, was obtained after electrolysis of 0.045% aqueous solution of sodium chloride. Freshly prepared AEW (pH 2.3–2.6, oxidation–reduction potential 1007–1025 mV, and free active chlorine concentration 27–35 ppm) was tested in vitro and (or) on tomato foliage and seed surfaces for its effects on the viability of plant pathogen propagules that could be potential seed contaminants. Foliar sprays of AEW were tested against bacterial spot disease of tomato under greenhouse and field conditions. The viability of propagules of Xanthomonas campestris pv. vesicatoria (bacterial spot pathogen), Streptomyces scabies (potato scab pathogen), and Fusarium oxysporum f.sp. lycopersici (root rot pathogen) was significantly reduced 4–8 log units within 2 min of exposure to AEW. Immersion of tomato seed from infected fruit in AEW for 1 and 3 min significantly reduced the populations of X. campestris pv. vesicatoria from the surface of the seed without affecting seed germination. Foliar sprays of AEW reduced X. campestris pv. vesicatoria populations and leaf spot severity on tomato foliage in the greenhouse. In the field, multiple sprays of AEW consistently reduced bacterial spot severity on tomato foliage. Disease incidence and severity was also reduced on fruit, but only in 2003. Fruit yield was either enhanced or not affected by the AEW sprays. These results indicate a potential use of AEW as a seed surface disinfectant or contact bactericide.Key words: electrolyzed oxidizing water, seed disinfectant, foliar sprays, bacterial spot control.

scholarly journals Automatic Detection and Severity Assessment of Pepper Bacterial Spot Disease via MultiModels Based on Convolutional Neural Networks

2020 ◽  
Vol 11 (2) ◽  
pp. 29-43
Author(s):  
Qiufeng Wu ◽  
Miaomiao Ji ◽  
Zhao Deng
Keyword(s):  
Neural Networks ◽  
Convolutional Neural Networks ◽  
Xanthomonas Campestris ◽  
Automatic Detection ◽  
Bacterial Disease ◽  
Severity Assessment ◽  
Bacterial Spot ◽  
Deep Convolutional Neural Networks ◽  
Spot Disease ◽  
Bacterial Spot Disease

Pepper bacterial spot disease caused by Xanthomonas campestris is the most common pepper bacterial disease, which ultimately reduces productivity and quality of products. This work uses deep convolutional neural networks (CNNs) to serve fine-grained pepper bacterial spot disease severity classification tasks. The pepper bacterial spot disease leaf images collected from the PlantVillage dataset are further annotated by botanists and split into healthy samples (label1), general samples (label2), and serious samples (label3). To extract more effective and discriminative features, an integrated neural network denoted as MultiModel_VGR is proposed for automatic detection and severity assessment of pepper bacterial spot disease, which is based on three powerful and popular deep learning architectures, namely VGGNet, GoogLeNet and ResNet. Compared with state-of-the-art single CNN architectures and binary-integrated MultiModels, MultiModel_VGR yields the best overall accuracy of 95.34% on the hold-out test dataset, which may have great potential in crop disease control for modern agriculture.

Erratum to “Reclassification of the Xanthomonads Associated with Bacterial Spot Disease of Tomato and Pepper”

2006 ◽  
Vol 29 (1) ◽  
pp. 85-86 ◽  
Author(s):  
Jeffrey B. Jones ◽  
George H. Lacy ◽  
Hacene Bouzar ◽  
Robert E. Stall ◽  
Norman W. Schaad
Keyword(s):  
Bacterial Spot ◽  
Spot Disease ◽  
Bacterial Spot Disease

PopW activates PAMP-triggered immunity in controlling tomato bacterial spot disease

2015 ◽  
Vol 463 (4) ◽  
pp. 746-750 ◽  
Author(s):  
Tian Wei ◽  
Luyao Wang ◽  
Xiaosi Zhou ◽  
Xiuyan Ren ◽  
Xiangqun Dai ◽  
...  
Keyword(s):  
Bacterial Spot ◽  
Spot Disease ◽  
Bacterial Spot Disease

scholarly journals Identification of Genes in Xanthomonas campestris pv. vesicatoria Induced during Its Interaction with Tomato

2007 ◽  
Vol 189 (17) ◽  
pp. 6359-6371 ◽  
Author(s):  
Dafna Tamir-Ariel ◽  
Naama Navon ◽  
Saul Burdman
Keyword(s):  
Xanthomonas Campestris ◽  
Disease Process ◽  
In Planta ◽  
Gene Encoding ◽  
Host Interaction ◽  
Citrate Transporter ◽  
Knockout Mutants ◽  
Bacterial Spot Disease

ABSTRACT Xanthomonas campestris pv. vesicatoria is the causal agent of bacterial spot disease of tomato and pepper. The disease process is interactive and very intricate and involves a plethora of genes in the pathogen and in the host. In the pathogen, different genes are activated in response to the changing environment to enable it to survive, adapt, evade host defenses, propagate, and damage the host. To understand the disease process, it is imperative to broaden our understanding of the gene machinery that participates in it, and the most reliable way is to identify these genes in vivo. Here, we have adapted a recombinase-based in vivo expression technology (RIVET) to study the genes activated in X. campestris pv. vesicatoria during its interaction with one of its hosts, tomato. This is the first study that demonstrates the feasibility of this approach for identifying in vivo induced genes in a plant pathogen. RIVET revealed 61 unique X. campestris pv. vesicatoria genes or operons that delineate a picture of the different processes involved in the pathogen-host interaction. To further explore the role of some of these genes, we generated knockout mutants for 13 genes and characterized their ability to grow in planta and to cause disease symptoms. This analysis revealed several genes that may be important for the interaction of the pathogen with its host, including a citH homologue gene, encoding a citrate transporter, which was shown to be required for wild-type levels of virulence.

Reclassification of the Xanthomonads Associated with Bacterial Spot Disease of Tomato and Pepper

2004 ◽  
Vol 27 (6) ◽  
pp. 755-762 ◽  
Author(s):  
Jeffrey B. Jones ◽  
George H. Lacy ◽  
Hacene Bouzar ◽  
Robert E. Stall ◽  
Norman W. Schaad
Keyword(s):  
Bacterial Spot ◽  
Spot Disease ◽  
Bacterial Spot Disease
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