Bacterial Leaf Spot and Blight of Sunflower Caused by Pseudomonas syringae pv. helianthi in Yugoslavia

Plant Disease ◽  
1989 ◽  
Vol 73 (4) ◽  
pp. 368 ◽  
Author(s):  
M. Arsenijevic
Keyword(s):  
Pseudomonas Syringae ◽  
Leaf Spot ◽  
Bacterial Leaf Spot

scholarly journals Epidemiology and management of bacterial leaf spot on watermelon caused byPseudomonas syringae

Plant Disease ◽  
2017 ◽  
Vol 101 (7) ◽  
pp. 1222-1229 ◽  
Author(s):  
E. A. Newberry ◽  
L. Ritchie ◽  
B. Babu ◽  
T. Sanchez ◽  
K. A. Beckham ◽  
...  
Keyword(s):  
Disease Severity ◽  
Pseudomonas Syringae ◽  
Leaf Spot ◽  
Negative Relationship ◽  
Disease Outbreaks ◽  
Field Trials ◽  
Multiple Regression Model ◽  
Bacterial Leaf Spot ◽  
Progress Curve ◽  
Cool Conditions

Bacterial leaf spot of watermelon caused by Pseudomonas syringae has been an emerging disease in the southeastern United States in recent years. Disease outbreaks in Florida were widespread from 2013 to 2014 and resulted in foliar blighting at the early stages of the crop and transplant losses. We conducted a series of field trials at two locations over the course of two years to examine the chemical control options that may be effective in management of this disease, and to investigate the environmental conditions conducive for bacterial leaf spot development. Weekly applications of acibenzolar-S-methyl (ASM) foliar, ASM drip, or copper hydroxide mixed with ethylene bis-dithiocarbamate were effective in reducing the standardized area under the disease progress curve (P < 0.05). Pearson’s correlation test demonstrated a negative relationship between the average weekly temperature and disease severity (–0.77, P = 0.0002). When incorporated into a multiple regression model with the square root transformed average weekly rainfall, these two variables accounted for 71% of the variability observed in the weekly disease severity (P < 0.0001). This information should be considered when choosing the planting date for watermelon seedlings as the cool conditions often encountered early in the spring season are conducive for bacterial leaf spot development.

scholarly journals Bacterial Leaf Spot of Celery in California: Etiology, Epidemiology, and Role of Contaminated Seed

Plant Disease ◽  
1997 ◽  
Vol 81 (8) ◽  
pp. 892-896 ◽  
Author(s):  
E. L. Little ◽  
S. T. Koike ◽  
R. L. Gilbertson
Keyword(s):  
Pseudomonas Syringae ◽  
Leaf Spot ◽  
Disease Incidence ◽  
Field Tests ◽  
Hot Water ◽  
Disease Development ◽  
Bacterial Leaf Spot ◽  
Overhead Irrigation ◽  
Celery Seed ◽  
Salinas Valley

Pseudomonas syringae pv. apii, causal agent of bacterial leaf spot (BLS) of celery, was first identified in California in 1989. By 1991, BLS was apparent in all celery-growing areas of the state. Greenhouse-produced transplants were affected most severely, and disease incidence approached 100% in some greenhouses. In this study, sources of inoculum and factors contributing to disease development were investigated in three Salinas Valley greenhouse operations during the 1991, 1992, and 1993 celery transplant seasons (January to August). Epiphytic P. syringae pv. apii was not detected on celery transplants until April or May of each year. Increased epiphytic populations preceded BLS outbreaks, and high-pressure, overhead irrigation favored bacterial infiltration and disease development. In seed-wash assays, P. syringae pv. apii was recovered from 5 of 24 commercial celery seed lots. In field tests, epiphytic P. syringae pv. apii was found on umbels of inoculated celery plants, and seeds from these plants were heavily contaminated with P. syringae pv. apii. Contaminated seed produced seedlings with large epiphytic P. syringae pv. apii populations. Hot-water treatment (50°C for 25 min) eliminated >99.9% of seed contamination. Based on these results, disease management techniques are proposed.

scholarly journals First Report of Pseudomonas syringae pv. aptata Causing Bacterial Leaf Spot on Sugar Beet in Serbia

Plant Disease ◽  
2015 ◽  
Vol 99 (2) ◽  
pp. 281-281 ◽  
Author(s):  
V. Stojšin ◽  
J. Balaž ◽  
D. Budakov ◽  
Slaviša Stanković ◽  
I. Nikolić ◽  
...  
Keyword(s):  
Sugar Beet ◽  
Pseudomonas Syringae ◽  
Leaf Spot ◽  
Leaf Surface ◽  
Negative Control ◽  
Gyrb Gene ◽  
Bacterial Suspension ◽  
Bacterial Strains ◽  
Gene Sequences ◽  
Bacterial Leaf Spot

A severe bacterial leaf spot was observed during June and July 2013 on commercial cultivars of sugar beet (Beta vulgaris var. saccharifera) in the Vojvodina Province of Serbia. Serbia is a major sugar beet production area in southeastern Europe, with 62,895 ha and 3 million tons of sugar beet yield in 2013. A foliar leaf spot observed in 25 commercial sugar beet fields surveyed ranged from 0.1 to 40% severity. Symptoms were characterized as circular or irregular, 5- to 20-mm diameter, white to light brown necrotic spots, each with a dark margin. Diseased leaves were rinsed in sterilized, distilled water (SDW) and dried at room temperature, and leaf sections taken from the margin of necrotic tissue were macerated in SDW. Isolations from 48 symptomatic leaves onto nutrient agar with 5% (w/v) sucrose (NAS) produced bacterial colonies that were whitish, circular, dome-shaped, and Levan-positive. Representative isolates (n = 105) were Gram negative; aerobic; positive for catalase, fluorescence on King's medium B, and tobacco hypersensitivity; and negative for oxidase, potato rot, and arginine dehydrolase. These reactions corresponded to LOPAT group Ia, which includes Pseudomonas syringae pathovars (2). Repetitive extragenic palindromic sequence (rep)-PCR was used for genetic fingerprinting the isolates using the REP, ERIC, and BOX primers. Twenty-five different profiles were obtained among the strains. From each profile group, one representative strain was sequenced for the gyrB gene (1). Four heterogenic groups were observed, and representative gyrB gene sequences of each group were deposited in the NCBI GenBank (Accession Nos. KJ950024 to KJ950027). The sequences were compared with those of pathotype strain P. syringae pv. aptata CFBP 1617 deposited in the PAMDB database; one strain was 100% homologous, and the other three were 99% homologous. To fulfill identification of the Serbian sugar beet isolates, gltA and rpoD partial gene sequences were determined (1), and the sequences were deposited as Accession Nos. KM386838 to KM386841 for gltA and KM386830 to KM38683033 for rpoD. The sequences were 100% homologous with those of pathotype strain CFBP 1617. Pathogenicity of each of four representative bacterial strains was tested on 3-week-old plants of the sugar beet cultivars Marinela, Serenada, and Jasmina (KWS, Belgrade, Serbia) and Lara (NS Seme, Novi Sad, Serbia) by atomizing a bacterial suspension of ~106 CFU/ml of the appropriate isolate onto the abaxial leaf surface of three plants per cultivar until water-soaking of the leaf surface was observed. Three plants of each cultivar atomized similarly with P. syringae pv. aptata CFBP 2473 and SDW served as positive and negative control treatments, respectively. Inoculated plants were kept in a clear plastic box at 80 to 100% RH and 17 ± 1°C and examined for symptom development over 3 weeks. For all test isolates and the control strain, inoculated leaves first developed water-soaked lesions 7 days after inoculation (DAI). By 10 to 14 DAI, lesions were necrotic and infection had spread to the petioles. By 21 DAI, wilting was observed on more than 50% of inoculated plants. Negative control plants were symptomless. Bacteria re-isolated onto NAS from inoculated leaves had the same colony morphology, LOPAT results, and gyrB partial gene sequences as described for the test strains. No bacteria were re-isolated from negative control plants. Based on these tests, the pathogen causing leaf spot on sugar beet in Serbia was identified as P. syringae pv. aptata. References: (1) P. Ferrente and M. Scortichini. Plant Pathol. 59:954, 2010. (2) R. A. Lelliott et al. J. Appl. Bacteriol. 29:470, 1966.

scholarly journals Complete and Draft Genome Sequences of the Cruciferous Pathogens Pseudomonas cannabina pv. alisalensis and Pseudomonas syringae pv. maculicola

2021 ◽  
Vol 10 (17) ◽  
Author(s):  
Takashi Fujikawa ◽  
Yuichi Takikawa ◽  
Yasuhiro Inoue
Keyword(s):  
Pseudomonas Syringae ◽  
Leaf Spot ◽  
Draft Genome ◽  
Leaf Blight ◽  
Bacterial Leaf Blight ◽  
Genome Sequences ◽  
Bacterial Leaf Spot ◽  
Content Type

ABSTRACT Pseudomonas cannabina pv. alisalensis and Pseudomonas syringae pv. maculicola cause bacterial leaf blight and bacterial leaf spot of crucifers (Brassicaceae). Both pathogens are threats to the cultivation of cruciferous crops. Here, we sequenced two strains of each pathogen, which will contribute to the development of countermeasures for the above diseases.

scholarly journals Report of Bacterial Leaf Spot on Collards and Turnip Leaves in Ohio

Plant Disease ◽  
2002 ◽  
Vol 86 (2) ◽  
pp. 186-186 ◽  
Author(s):  
M. L. Lewis Ivey ◽  
S. Wright ◽  
S. A. Miller
Keyword(s):  
Pseudomonas Syringae ◽  
Leaf Spot ◽  
Xanthomonas Campestris ◽  
Similarity Index ◽  
Acid Methyl Ester ◽  
Bacterial Suspension ◽  
Water Control ◽  
Bacterial Leaf Spot ◽  
Turnip Leaves ◽  
Negative Controls

In 2000, circular water-soaked lesions typical of bacterial leaf spot were observed on leaves of collards (Brassica oleracea L. var. viridis) throughout commercial fields in northwest Ohio. Light brown, rectangular, water-soaked lesions were observed on turnip leaves (Brassica rapa L.). Bacterial streaming from lesions on both crops was observed microscopically. Cream colored, fluorescent colonies were isolated from diseased tissues on Pseudomonas F medium, and eight representative colonies (four from collards and four from turnip) were selected and purified. Fatty acid methyl ester analysis was performed on all of the isolates. Two from collards and two from turnip were identified as Pseudomonas syringae pv. maculicola (mean similarity index = 0.82 [MIDI Inc., Newark, DE]). DNA extracts from pure cultures of the P. syringae pv. maculicola strains were used as template in a polymerase chain reaction (PCR) assay with primers derived from the region of the coronatine gene cluster controlling synthesis of the coronafacic acid moiety found in P. syringae pv. tomato and P. syringae pv. maculicola (CorR and CorF2) (D. Cuppels, personal communication). DNA from P. syringae pv. tomato strain DC3000 and P. syringae pv. maculicola strain 88–10 (2) served as positive controls, while water and DNA from Xanthomonas campestris pv. vesicatoria strain Xcv 767 were used as negative controls. The expected 0.65-kb PCR product was amplified from three of four strains (two from turnip and one from collards) and the positive control DNA, but not from the negative controls. Pathogenicity tests were performed twice on 6-week-old turnip (‘Forage Star’, ‘Turnip Topper’, ‘Turnip Alamo’, ‘Turnip 7’), collard (‘Champion’) and mustard (Brassica juncea L. ‘Southern Giant Curl’) seedlings using the three PCR-positive strains. Premisted seedlings were spray-inoculated separately with each of the three strains (2 × 108 CFU/ml, 5 ml per plant) and a water control. Greenhouse temperatures were maintained at 20 ± 1°C. For both tests, all strains caused characteristic lesions on all of the crucifer cultivars within 5 days after inoculation; the control plants did not develop symptoms. To satisfy Koch's postulates, one of the turnip strains was reisolated from ‘Turnip Topper’ plants, and the collard strain was reisolated from ‘Champion’ plants. The three original and two reisolated strains induced a hypersensitive response in Mirabilis jalapa L. and Nicotiana tabacum L. var. xanthia plants 24 h after inoculation with a bacterial suspension (1 × 108 CFU/ml). The original and reisolated strains were compared using rep-PCR with the primer BOXA1R (1). The DNA fingerprints of the reisolated strains were identical to those of the original strains. To our knowledge, this is the first report of bacterial leaf spot on commercially grown collards and turnip greens in Ohio. References: (1) B. Martin et al. Nucleic Acids Res. 20:3479, 1992. (2) R. A. Moore et al. Can. J. Microbiol. 35:910, 1989.

scholarly journals Testing of different methods for identification of bacterial leaf spot (Siringae pv. maculicola (Mcculloch) Young et al.) plant pathogen in cauliflower leaves

2021 ◽  
Vol 1 (25) ◽  
pp. 174-186
Author(s):  
S.I. Prikhodko ◽  
◽  
A.B. Yaremko ◽  
K.P. Kornev ◽  
◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Leaf Spot ◽  
Biochemical Properties ◽  
Analytical Sensitivity ◽  
Bacterial Strains ◽  
Bacterial Leaf Spot ◽  
Plant Quarantine ◽  
Test Kit ◽  
Russian Plant

Pseudomonas syringae pv. maculicola (McCulloch) Young et al. is a pathogen of cauliflower bacterial spot that affects many plants of the Cruciferae family. The need for quality diagnostics of this species arose due to the mandatory phytosanitary inspection of places of production of plant products intended for export. Our research aims at determining a set of methods for the diagnosis of the pathogen of cauliflower bacterial leaf spot and evaluating these methods’ applicability in laboratory practice. The object of the research is P. syringae pv. maculicola – the causative agent of cauliflower bacterial leaf spot.The article presents the test results of two methods for the identification of Pseudomonas syringae pv. maculicola (McCulloch) Young et al. carried out in 2020 at the All-Russian Plant Quarantine Center (VNIIKR). The first method is based on the determination of biochemical properties using the API 20E test kit produced by bioMérieux’s (France); the second one – is a conventional PCR. The type bacterial strain CFBP 1657 obtained by specialists of the All-Russian Plant Quarantine Center (VNIIKR) from French collection of plant-associated bacteria (Cirm-CFBP) was used in the studies. A comparison of the biochemical properties of 23 bacteria of the genus Pseudomonas showed that there are only two characteristics within this test that distinguish P. s. pv. maculicola from other species pathovars: acetoin products and gelatin hydrolysis. Two pairs of primers with different targets in the P. syringae genome were also tested. PCR with PsyF/PsyR primers demonstrated the highest similarity of the obtained fragments with the NCBI database (97.2 %). The analytical sensitivity of PCR with PsyF/PsyR primers in plant and seed extracts was 105 CFU/ml. Determination of analytical specificity with 33 bacterial strains of the genus Pseudomonas revealed cross-reactions with strains of the following species: P. congelans, P. savastanoi pv. phaseolicola, P. savastanoi pv. glycinea, P. syringae pv. coronafaciens, P. syringae pv. syringae. Thus, to differentiate the species by means of PCR with PsyF/PsyR primers, the nucleotide sequence of the obtained amplification products should be additionally determined by Sanger sequencing.

scholarly journals First Report of Bacterial Leaf Spot of Spinach Caused by a Pseudomonas syringae Pathovar in California

Plant Disease ◽  
2002 ◽  
Vol 86 (8) ◽  
pp. 921-921 ◽  
Author(s):  
S. T. Koike ◽  
H. R. Azad ◽  
D. C. Cooksey
Keyword(s):  
Brassica Oleracea ◽  
Beta Vulgaris ◽  
Pseudomonas Syringae ◽  
Leaf Spot ◽  
The United States ◽  
Nutrient Broth ◽  
Bacterial Leaf Spot ◽  
First Report ◽  
Leaf Spots ◽  
Initial Symptoms

In 2000 and 2001, a new disease was observed on commercial spinach (Spinacia oleracea) in the Salinas Valley, Monterey County, CA. Initial symptoms were water-soaked, irregularly shaped leaf spots (2 to 3 mm diameter). As the disease developed, spots enlarged to as much as 1 to 2 cm, were vein-delimited, and turned dark brown. Faint chlorotic halos sometimes surrounded the spots. Death of large areas of the leaf occurred if spots coalesced. Spots were visible from the adaxial and abaxial sides of leaves, and no fungal structures were observed. The disease occurred on newly expanded and mature foliage. No fungi were isolated from the spots. However, cream-colored bacterial colonies were consistently isolated on sucrose peptone agar, and these strains were nonfluorescent on King's medium B. Strains were positive for levan and negative for oxidase, arginine dihydrolase, and nitrate reductase. Strains did not grow at 36°C, did not rot potato slices, but induced a hypersensitive reaction in tobacco (Nicotiana tabacum cv. Turk). These results suggested the bacterium was similar to Pseudomonas syringae. Fatty acid methyl ester (FAME) analysis (MIS-TSBA 4.10, MIDI Inc., Newark, DE) indicated the strains were highly similar (80.1 to 89.3%) to P. syringae pv. maculicola. However, in contrast to P. syringae pv. maculicola, the spinach strains did not utilize the carbon sources erythritol, L+tartrate, L lactate, and DL-homoserine. Pathogenicity of 10 strains was tested by growing inoculum in nutrient broth shake cultures for 48 h, diluting to 106 CFU/ml, and spraying 4-week-old plants of spinach cv. Bossanova. Control plants were sprayed with sterile nutrient broth. After 5 to 8 days in a greenhouse (24 to 26°C), leaf spots identical to those observed in the field developed on cotyledons and true leaves of inoculated plants. Strains were reisolated from the spots and identified as P. syringae. Control plants remained symptomless. The 10 strains were also inoculated on beet (Beta vulgaris), Swiss chard (Beta vulgaris subsp. cicla), cilantro (Coriandrum sativum), and spinach. Spinach showed leaf spots after 8 days; however, none of the other plants developed symptoms. Two strains were inoculated onto spinach cvs. Califlay, Lion, Nordic IV, Polka, Resistoflay, Rushmore, RZ 11, Spinnaker, Springfield, Viroflay, and Whitney. Leaf spot developed on all cultivars, and the pathogen was reisolated. Because the FAME data indicated a similarity between the spinach pathogen and P. syringae pv. maculicola, we inoculated sets of spinach cv. Bolero, cabbage (Brassica oleracea subsp. capitata cv. Grenedere), and cauliflower (Brassica oleracea subsp. botrytis cv. White Rock) with three P. syringae pv. maculicola and three spinach strains. Cabbage and cauliflower developed leaf spots only when inoculated with P. syringae pv. maculicola; spinach had leaf spots only when inoculated with the spinach strains. All inoculation experiments were done twice, and the results of the two tests were the same. To our knowledge, this is the first report of bacterial leaf spot of spinach in California caused by a nonfluorescent P. syringae, and the first record of this disease in the United States. Biochemical characteristics and limited host range of the pathogen indicate the California strains are likely the same as the P. syringae pv. spinaciae pathogen that was reported in Italy (1) and Japan (2). References: (1) C. Bazzi et al. Phytopathol. Mediterr. 27:103, 1988. (2) K. Ozaki et al. Ann. Phytopathol. Soc. Jpn. 64:264, 1998.

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