Screening for bacterial fruit blotch resistance in watermelon fruit

Acidovorax citrulli (A. citrulli) strains cause bacterial fruit blotch (BFB) in cucurbit crops and affect melon significantly. Numerous strains of the bacterium have been isolated from melon hosts globally. Strains that are aggressively virulent towards melon and diagnostic markers for detecting such strains are yet to be identified. Using a cross-inoculation assay, we demonstrated that two Korean strains of A. citrulli, NIHHS15-280 and KACC18782, are highly virulent towards melon but avirulent/mildly virulent to the other cucurbit crops. The whole genomes of three A. citrulli strains isolated from melon and three from watermelon were aligned, allowing the design of three primer sets (AcM13, AcM380, and AcM797) that are specific to melon host strains, from three pathogenesis-related genes. These primers successfully detected the target strain NIHHS15-280 in polymerase chain reaction (PCR) assays from a very low concentration of bacterial gDNA. They were also effective in detecting the target strains from artificially infected leaf, fruit, and seed washing suspensions, without requiring the extraction of bacterial DNA. This is the first report of PCR-based markers that offer reliable, sensitive, and rapid detection of strains of A. citrulli causing BFB in melon. These markers may also be useful in early disease detection in the field samples, in seed health tests, and for international quarantine purposes.

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Studies on control of seed borne bacterial vegetable disease: studies on epidemiology and control of cucurbits bacterial fruit blotch

Journal of General Plant Pathology ◽

10.1007/s10327-021-01034-5 ◽

2021 ◽

Author(s):

Takashi Shirakawa

Keyword(s):

Bacterial Fruit Blotch ◽

And Control

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Bacteriophage Biocontrol of Acidovorax citrulli, the Causal Agent of Bacterial Fruit Blotch

Proceedings ◽

10.3390/proceedings2020050010 ◽

2020 ◽

Vol 50 (1) ◽

pp. 10

Author(s):

Aryan Rahimi-Midani ◽

Tae-Jin Choi

Keyword(s):

Crop Production ◽

Germination Rate ◽

Causal Agent ◽

Head Size ◽

Genotype I ◽

Bacterial Fruit Blotch ◽

Double Stranded Dna ◽

Acidovorax Citrulli ◽

Group I ◽

Next Generation Sequencing Ngs

Bacterial fruit blotch caused by Acidovorax citrulli is known to be the major threat to cucurbit crop production worldwide. The pathogen can penetrate into seed coat and cause disease symptoms at any stage of plant growth, which results in fruit loss. Two main genotypes (genotype I and II) are reported in A. citrulli, in which genotype II is the main cause of Bacterial Fruit Blotch (BFB) in watermelon and group I is known to be a causal agent of BFB in melon. To date, there are no commercially available cultivars resistant to BFB, and available strategies are not able to completely manage the disease. In this study, we aim to isolate bacteriophages to control BFB. Samples collected from watermelon, melon, and pumpkin were used to isolate bacteriophages. All isolated bacteriophages were tested against 42 strains of A. citrulli, among which two phages with the ability to lyse a greater number of hosts were selected and characterized. Bacteriophage ACP17 from the Myoviridae family, with a head size of 100 ± 5 nm and tail of 150 ± 5 nm, infected 29 strains of A. citrulli mostly belonging to genotype group I, whereas the second isolated bacteriophage, ACPWH from Siphoviridae, with a head size of 60 ± 5 nm and tail of 180 ± 5 nm, infected 39 A. citrulli strains. Genome analysis of both bacteriophages using Next generation Sequencing (NGS) showed that ACP17 and ACPWH have double-stranded DNA with sizes of 156,972 kb and 424,299 kb, respectively. Watermelon seeds coated with ACPWH showed a germination rate of up to 90% in the presence of A. citrulli in contrast to untreated seed, which showed no germination or germinated juveniles with BFB symptoms in the presence of A. citrulli. The results of this study show that the use of bacteriophages of A. citrulli represents a potential biocontrol method for controlling BFB.

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DETEKSI PENYAKIT BACTERIAL FRUIT BLOTCH PADA MELON MENGGUNAKAN ELISA (DETECTION OF BACTERIAL FRUIT BLOTCH OF MELON USING ELISA)

Jurnal Perlindungan Tanaman Indonesia ◽

10.22146/jpti.16012 ◽

2016 ◽

Vol 19 (1) ◽

pp. 1

Author(s):

Utik Windari ◽

Tri Joko ◽

Siti Subandiyah

Keyword(s):

Detection Method ◽

Yield Losses ◽

Elisa Method ◽

Bacterial Fruit Blotch ◽

Acidovorax Citrulli ◽

Commercial Seed ◽

Seedborne Disease ◽

Dark Green ◽

Das Elisa ◽

Special Region

Bacterial fruit blotch (BFB) caused by Acidovorax citrulli is a serious seedborne disease in Cucurbitaceae causing 90-100% yield losses. The aim of this study was to explore BFB symptom on melon and also to detect A. citrulli infection in commercial seed and symptomatic fruits from the field in Yogyakarta Special Region province and its surrounding using DAS-ELISA method. Samples include melon from Sleman, Bantul, Kulon Progo, Gunung Kidul, Magelang, Purworejo regencies while commercial seeds i.e. Action 434, Glamour and Mai 116 were collected. DASELISA detection method used reagent set from Agdia. Based on the field observation, this study found melon commercial fruit shares similar symptom with BFB, which showed discrete oily dark green spots, while the netting failed to develop over necrotic areas, resulting in smooth sunken spots. DAS-ELISA detection revealed that samples collected from Jetak village, district of Mungkid, Magelang and from Bligo village, district of Ngluwar, Magelang and in commercial seed Mai 116 were positively infected byA. citrulli.Keywords: Acidovorax citrulli, bacterial fruit blotch, ELISA, melonBacterial fruit blotch (BFB) merupakan penyakit penting pada famili Cucurbitaceae yang disebabkan oleh Acidovorax citrulli. Penyakit ini dilaporkan dapat menurunkan hasil mencapai 90-100%. Tujuan dari penelitian ini adalah untuk mengetahui gejala penyakit BFB pada melon dan deteksiA. citrulli pada benih komersial dan sampel buah bergejala dengan metode DAS-ELISA di DIY dan sekitarnya. Pengambilan sampel dilakukan di kabupaten Sleman, Bantul, Kulon Progo, Gunung Kidul, Purworejo dan Magelang. Selain dari lapangan, diuji pula benih melon komersial yaitu Action-434, Glamour dan Mai 116. Metode deteksi dengan ELISA menggunakanreagent set dari Agdia. Dari hasil pengamatan di lapangan ditemukan buah melon dengan gejala yang mirip dengan gejala BFB yaitu adanya becak berwarna hijau tua kebasahan pada permukaan buah, jaring tidak terbentuk sempurna dan pada bagian daging buah di bawah becak tadi membusuk. Hasil deteksi dengan DAS-ELISAmengindikasikan bahwa A. citrulli terdeteksi pada sampel yang berasal dari desa Bligo, kecamatan Ngluwar dan desa Jetak, kecamatan Mungkid, kabupaten Magelang, serta pada benih komersial MAI 116.Kata kunci: Acidovorax citrulli, bacterial fruit blotch, ELISA, melon

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Analysis of Control Efficacy of Bacterial Fruit Blotch Caused by Acidovorax avenae subsp. citrulli in Recent Issues

The Korean Journal of Pesticide Science ◽

10.7585/kjps.2016.20.1.41 ◽

2016 ◽

Vol 20 (1) ◽

pp. 41-46

Author(s):

Chang-Gi Back ◽

Sung-Chan Lee ◽

Mi-Jeoung Park ◽

Kyung-Sook Han ◽

Hong-Ki Kim ◽

...

Keyword(s):

Control Efficacy ◽

Bacterial Fruit Blotch

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First Report of Bacterial Fruit Blotch of Watermelon Caused by Acidovorax avenae subsp. citrulli in Illinois

Plant Disease ◽

10.1094/pdis.2002.86.4.443a ◽

2002 ◽

Vol 86 (4) ◽

pp. 443-443 ◽

Cited By ~ 3

Author(s):

M. Babadoost ◽

N. Pataky

Keyword(s):

Citrullus Lanatus ◽

Test Tube ◽

Green Water ◽

Enzyme Linked Immunosorbent Assay ◽

Distilled Water ◽

Mature Fruit ◽

American Phytopathological Society ◽

Bacterial Fruit Blotch ◽

Dark Green ◽

Fruit Surface

In August 2001, symptomatic mature fruit of watermelon (Citrullus lanatus) cvs. Crimson Sweet and Royal Sweet were collected from six fields (48 ha) in Iroquois, Kankakee, and Mason counties in Illinois. The fruit surface had dark green, water-soaked lesions, and the rind's epidermis was cracked. Sections of infected rind were examined with a light microscope, and bacterial streaming was observed. Rind tissue was disinfested by rubbing the fruit surface with a paper towel moistened with 70% ethanol. Pieces of rind from the margins of lesions were placed in a test tube containing sterile-distilled water. The tube was shaken, and the suspension was streaked on King's medium B agar in petri plates. The plates were incubated at 26°C for 3 days. A nonfluorescent, gramnegative, anaerobic, oxidase-positive, rod-shaped bacterium was isolated that produced creamy white colonies on nutrient agar. The bacterium was identified as Acidovorax avenae subsp. citrulli based on an enzyme-linked immunosorbent assay test specific for A. avenae subsp. citrulli (kit PSA 14,800; Agdia Inc., Elkhart, IN). The disease was diagnosed as bacterial fruit blotch (1,2). The occurrence of bacterial fruit blotch of watermelon in Illinois is important because (i) watermelon is widely grown in Illinois, (ii) the pathogen also infects melons and pumpkins, and (iii) Illinois grows approximately 1,000 ha of melons and 8,000 ha of pumpkins. References: (1) R. X. Latin. Bacterial fruit blotch. Pages 34-35 in: Compendium of Cucurbit Diseases. The American Phytopathological Society, St. Paul, MN,1996. (2) G. S. Somodi et al. Plant Dis. 75:1053, 1991.

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Identifying pathogenic determinants of Acidovorax citrulli toward the control of bacterial fruit blotch of cucurbits

10.32747/2014.7598168.bard ◽

2014 ◽

Author(s):

Bingyu Zhao ◽

Saul Burdman ◽

Ronald Walcott ◽

Tal Pupko ◽

Gregory Welbaum

Keyword(s):

Host Preference ◽

Biochemical Properties ◽

Bacterial Fruit Blotch ◽

Group I ◽

Experimental Approaches ◽

Major Factors ◽

Bacterial Genes ◽

Relationship Of ◽

The Relationship

The specific objectives of this BARD proposal were: Use a comparative genomics approach to identify T3Es in group I, II and III strains of A. citrulli. Determine the bacterial genes contributing to host preference. Develop mutant strains that can be used for biological control of BFB. Background to the topic: Bacterial fruit blotch (BFB) of cucurbits, caused by Acidovoraxcitrulli, is a devastating disease that affects watermelon (Citrulluslanatus) and melon (Cucumismelo) production worldwide, including both Israel and USA. Three major groups of A. citrullistrains have been classified based on their virulence on host plants, genetics and biochemical properties. The host selection could be one of the major factors that shape A. citrullivirulence. The differences in the repertoire of type III‐ secreted effectors (T3Es) among the three A. citrulligroups could play a major role in determining host preferential association. Currently, there are only 11 A. citrulliT3Es predicted by the annotation of the genome of the group II strain, AAC00‐1. We expect that new A. citrulliT3Es can be identified by a combination of bioinformatics and experimental approaches, which may help us to further define the relationship of T3Es and host preference of A. citrulli. Implications, both scientific and agricultural: Enriching the information on virulence and avirulence functions of T3Es will contribute to the understanding of basic aspects of A. citrulli‐cucurbit interactions. In the long term, it will contribute to the development of durable BFB resistance in commercial varieties. In the short term, identifying bacterial genes that contribute to virulence and host preference will allow the engineering of A. citrullimutants that can trigger SAR in a given host. If applied as seed treatments, these should significantly improve the effectiveness and efficacy of BFB management in melon and atermelon production.

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