scholarly journals First Report of Bacterial Leaf Spot of Witloof, Caused by Pseudomonas cichorii in Korea

Plant Disease ◽  
2013 ◽  
Vol 97 (10) ◽  
pp. 1376-1376 ◽  
Author(s):  
I.-S. Myung ◽  
J.-K. Choi ◽  
J. Y. Lee ◽  
M.-J. Yoon ◽  
E. Y. Hwang ◽  
...  
Keyword(s):  
16S Rrna ◽  
Economic Impact ◽  
Leaf Spot ◽  
Reference Strain ◽  
Bacterial Leaf Spot ◽  
Pseudomonas Cichorii ◽  
First Report ◽  
Field Isolates ◽  
Original Field ◽  
Index Value

In August 2011, bacterial leaf spot was observed on witloof (Cichorium intybus L. var. foliosum) grown in a commercial field with 15% incidence in Injae, Korea. Symptoms on leaves included irregular brown to reddish brown spots in the center. Bacterial streaming from the lesions was observed microscopically. Bacterial isolates (BC3286, BC3287, and BC3308-BC3310) were recovered on Trypticase soy agar from lesions surface-sterilized in 70% ethyl alcohol for 30 s. The isolates were gram negative, urease negative, fluorescent on King's B agar, and had aerobic rods with 2 to 6 polar flagella. Pathogenicity tests were separately performed in different greenhouses located in Suwon (National Academy of Agricultural Science) and Chuncheon (Gangwondo Agricultural Research and Extension Services) in Korea. Pathogenicity was confirmed by spray inoculation of healthy, 10-day-old leaves of witloof plants (two plants/isolate) with a suspension of original field isolate (106 CFU/ml). Sterile distilled water was used as negative control. The inoculated plants were incubated in a growth chamber (25°C and 95% relative humidity [RH]) overnight, then transferred to a greenhouse at 23 to 27°C and 60 to 70% RH. Characteristic leaf spot symptoms were observed on inoculated witloof plants 8 days after inoculation. No symptoms were observed on control plants. The bacterium reisolated from the inoculated leaves was confirmed by analyzing sequence of the gyrB gene with direct sequencing method of PCR products using primers gyr-F and gyr-R (2). The sequence of reisolated bacteria shared 100% similarity with inoculated ones. In LOPAT (1) tests, all isolates and the reference strain of Pseudomonas cichorii CFBP2101T (=BC2595) were levan negative, oxidase positive, potato rot negative, arginine dihydrolase negative, and tobacco hypersensitivity positive, indicative of group III (–, +, –, –, +) of fluorescent pseudomonads. The 16S rRNA (1,408 bp), and gyrB (676 bp) regions were sequenced to aid in identification of the original field isolates as well as P. cichorii CFBP 2101T (=BC2595) using reported sets of PCR primers, fD1/rP2 and gyr-F/gyr-R, respectively (2,4). Phylogenetic analyses based on partial sequences of the gyrB and the 16S rRNA of Psudomonas spp. available in GenBank, the reference strain of P. cichorii CFBP2101T (=BC2595), and the witloof field isolates were conducted using the neighbor-joining method with Juke-Cantor model of distance calculation in MEGA version 5.1 (3). The isolates and the reference strain of P. cichorii CFBP2101T (=BC2595) was clustered in one group with P. cichorii strains in both phylogenetic trees based on the two sequences. Sequences of the 16S rRNA region had a distance index value ranging from 0.000 to 0.001 between the reference strain of P. cichori CFBP2101T (GenBank JX913784) and the field isolates (JX913785 to JX913789), and ranged from 0.000 to 0.001 within the field isolates. Sequences of the gyrB region had a distance index value ranging 0.029 to 0.033 between the reference strain (JX913790) and the field isolates (JX913791 to JX913795), and ranged from 0.000 to 0.041 within the field isolates. To our knowledge, this is the first report of bacterial leaf spot of witloof caused by P. cihorii in Korea. P. cichorii has a wide host range, and an important economic impact on vegetables. The disease is expected to result in a significant economic impact on root production of witloof in Korea. References: (1) R. A. Lelliott et al. J. Appl. Bacteriol. 29:470, 1966. (2) H. Sawada et al. J. Mol. Evol. 49:627, 1999. (3) K. Tamura et al. Mol. Biol. Evol. 28:2731, 2011. (4) W. G. Weinsburg et al. J. Bacteriol. 173, 697, 1991.

scholarly journals First Report of Bacterial Leaf Spot on Cichorium intybus Caused by Pseudomonas cichorii in Florida

Plant Disease ◽  
2013 ◽  
Vol 97 (6) ◽  
pp. 837-837 ◽  
Author(s):  
S. Zhang ◽  
Y. Fu
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Leaf Spot ◽  
South Florida ◽  
Cichorium Intybus ◽  
Rrna Gene ◽  
Fluorescent Pseudomonad ◽  
Bacterial Leaf Spot ◽  
Pseudomonas Cichorii ◽  
First Report

Italian dandelion (Cichorium intybus L.) is a leafy chicory plant grown as a fresh vegetable in salads. In August 2011, necrotic lesions were observed on leaves of about 20% of the Italian dandelion plants in an experimental field at the Tropical Research and Education Center (TREC) of the University of Florida in Homestead, FL. The lesions were dark brown with a yellow halo and most were irregular in shape. Some lesions formed along the leaf edge and developed into large lesions up to 20 to 30 mm long. Symptomatic leaf tissues were cut into small pieces (2 to 3 mm), sterilized in 10% Clorox (0.6% sodium hypochlorite) for 2 min following surface disinfection in 70% ethanol for 30 s, placed on nutrient agar (NA), and incubated at 28°C in the dark for 4 to 5 days. A bacterium was consistently isolated from the leaf lesions. Colonies of these bacteria were raised, opaque, and round with a slightly irregular, colorless margin while the center was light brown. The colonies were gram-negative with yellow fluorescence appearance on Pseudomonas F agar (Becton, Dickinson and Company, Sparks, MD). LOPAT tests were carried out to further identify the species of this fluorescent pseudomonad (2). The bacterium was levan negative, oxidase positive, potato rot negative, arginine dihydrolase negative, and tobacco hypersensitivity positive. Results from this test indicated that the bacterium belongs to LOPAT group III of fluorescent pseudomonads. Bacterial identity was further confirmed as Pseudomonas cichorii by amplifying the 16S rRNA gene with the universal bacterial primers 8F and 1492R (1) and sequence analysis (GenBank Accession No. KC311733). The partial 1,361-bp 16S rRNA gene sequences had 100% identity with P. cichorii (JF951725.1), which was isolated from infected soybean plants. Pathogenicity of the isolate was tested twice by spraying a suspension of the bacterium (107 CFU/ml) onto three 4-week-old plants until runoff. The control plants were sprayed with sterile distilled water. All plants were covered with plastic bags to maintain moisture for 48 h in an air-conditioned greenhouse (22 ± 1°C). Similar lesions were observed on the inoculated plant leaves 5 to 7 days after inoculation, whereas no lesions were developed on the control plants. Bacterial colonies with same morphology were recovered from the lesions, fulfilling Koch's postulates. P. cichorii is widespread worldwide with an important economic impact on celery, chrysanthemum, and lettuce. In South Florida, P. cichorii was reported as the causal agent of bacterial leaf spot on escarole (Cichorium endivia L.) (3). To our knowledge, this is the first report of bacterial leaf spot on Italian dandelion caused by P. cichorii in Florida. References: (1) J. P. Galkiewicz and C. A. Kellogg. Appl. Environ. Microbiol. 74:7828, 2008. (2) T. Goszczynska et al. Introduction to Practical Phytobacteriology. Isteg Scientific Publications, Irene, South Africa, 2000. (3) K. Pernezny and R. N. Raid. Plant Dis. 85:1208, 2001.

scholarly journals First Report of Leaf Spot Caused by Pseudomonas cichorii on Coreopsis lanceolata in Italy

Plant Disease ◽  
2009 ◽  
Vol 93 (9) ◽  
pp. 967-967 ◽  
Author(s):  
A. Garibaldi ◽  
G. Gilardi ◽  
C. Moretti ◽  
M. L. Gullino
Keyword(s):  
Leaf Spot ◽  
Casein Hydrolysate ◽  
Its Region ◽  
Soft Rot ◽  
Chrysanthemum Morifolium ◽  
Luria Bertani ◽  
Nutrient Broth ◽  
Bacterial Leaf Spot ◽  
Pseudomonas Cichorii ◽  
First Report

Coreopsis lanceolata L. (Compositae), an ornamental species grown in parks and gardens, is very much appreciated for its long-lasting flowering period. In August of 2008, pot-grown plants with necrotic leaf lesions were observed in a commercial nursery located near Biella (northern Italy). Lesions were present, especially along the margin of basal leaves, and sometimes had a chlorotic halo. On infected leaves, dark brown necrosis developed. Leaf stalks were sometimes affected. In many cases, the leaves, especially those at collar level, were withered. Of 1,500 plants, 15% were infected by the disease. Microscopic examination did not reveal any fungal structures within the lesions. Small fragments of tissue from 30 affected leaves were macerated for 15 min in casein hydrolysate and 0.1-ml aliquots of the resulting suspension were spread onto Luria Bertani agar (LB) and potato dextrose agar (PDA). Plates were maintained at 22 ± 1°C for 48 h. No fungi were isolated from the leaf spots on LB or PDA. Colonies similar to those of Pseudomonas spp. were consistently isolated on LB. Colonies were fluorescent on King's medium B, levan negative, oxidase positive, potato soft rot negative, arginine dihydrolase negative, and tobacco hypersensitivity positive (LOPAT test). The bacterial colonies were identified as Pseudomonas cichorii (2). The internal transcribed spacer (ITS) region of rDNA was amplified using primers 27F and 1492R and sequenced (GenBank Accession No. FJ534557). BLAST analysis (1) of the 998-bp segment showed a 98% homology with the sequence of P. cichorii. The pathogenicity of one isolate was tested twice by growing the bacterium in nutrient broth shake cultures for 48 h at 20 ± 1°C. The suspension was centrifuged, the cell pellet resuspended in sterile water to a concentration of 107 CFU/ml, and 30 4-month-old healthy coreopsis plants were sprayed with the inoculum. The same number of plants was sprayed with sterile nutrient broth as a control. After inoculation, plants were covered with plastic bags for 48 h and placed in a growth chamber at 20 ± 1°C. Five days after inoculation, lesions similar to those seen in the field were observed on all plants inoculated with the bacterium, but not on the controls. Ten days later, 40% of the leaves were withered. Isolations were made from the lesion margins on LB and the resulting bacterial colonies were again identified as P. cichorii. The pathogen caused the same symptoms also on plants of Dendranthema frutescens (cv. Camilla), Chrysanthemum morifolium (cvs. Eleonora and Captiva), and an Osteospermum sp. (cv. Wild side) when artificially inoculated with the pathogen with the same methodology. The same bacterial leaf spot caused by P. cichorii was observed in 2005 in other nurseries in the same area on Phlox paniculata (3). To our knowledge, this is the first report of bacterial leaf spot caused by P. cichorii on C. lanceolata in Italy. References: (1) S. F. Altschul et al. Nucleic Acids Res. 25:3389, 1997. (2) H. Bergey et al. Bergey's Manual on Determinative Bacteriology. Williams and Wilkins, Baltimore, MD, 1994. (3) A. Garibaldi et al. Plant Dis. 89:912, 2005.

scholarly journals First Report of Bacterial Leaf Spot of Cucumber Caused by Pseudomonas cichorii in China

Plant Disease ◽  
2019 ◽  
Vol 103 (1) ◽  
pp. 147
Author(s):  
X. Y. Fu ◽  
R. Y. Zhang ◽  
Z. Q. Tan ◽  
T. Liu ◽  
Z. Q. Peng
Keyword(s):  
Leaf Spot ◽  
Bacterial Leaf Spot ◽  
Pseudomonas Cichorii ◽  
First Report

scholarly journals First Report of Bacterial Leaf Spot Caused by Pseudomonas cichorii on Thai Basil in Hawaii

Plant Disease ◽  
2018 ◽  
Vol 102 (12) ◽  
pp. 2637-2637
Author(s):  
B. C. Luiz ◽  
W. P. Heller ◽  
E. Brill ◽  
B. C. Bushe ◽  
L. M. Keith
Keyword(s):  
Leaf Spot ◽  
Bacterial Leaf Spot ◽  
Pseudomonas Cichorii ◽  
First Report

scholarly journals First Report of Basil Leaf Spot Caused by Pseudomonas cichorii in Louisiana and Cultivar Screening Results

Plant Disease ◽  
1998 ◽  
Vol 82 (11) ◽  
pp. 1283-1283 ◽  
Author(s):  
G. E. Holcomb ◽  
P. J. Cox
Keyword(s):  
Leaf Spot ◽  
Screening Tests ◽  
Minor Importance ◽  
Bacterial Cells ◽  
Bacterial Leaf Spot ◽  
Pseudomonas Cichorii ◽  
First Report ◽  
Sweet Basil ◽  
Leaf Spots ◽  
Cultivar Screening

A leaf spot of basil, Ocimum basilicum L., was observed on container-grown and field plantings of cultivars Aussie Sweet and Sweet Basil. The disease was of minor importance under field conditions, but was of potential economic importance in seedling production. Gray to black, watersoaked, necrotic spots commonly developed at leaf margins. Large numbers of bacteria were released from cut lesions when viewed by light microscopy. Single colony bacterial isolates were established on nutrient dextrose agar (NDA) and yeast extract-dextrose-calcium carbonate agar (YDC). Pathogencity tests were performed by misting a water suspension containing 104 bacterial cells per ml on healthy basil plants. Plants were held for 24 h in a dew chamber at 26°C and then moved to a greenhouse for observation. Typical leaf spots developed on inoculated plants in 2 days, but not on healthy control plants, and the bacterium was reisolated. The bacterium was characterized as a gram-negative, motile rod, negative for potato rot test, positive in tobacco hypersensitivity test, and oxidase positive. Isolates were identified as Pseudomonas cichorii according to the Biolog Microplate system (similarities ranged from 0.937 to 0.995). Screening tests were conducted by inoculating 15 basil cultivars, six replicates each, and rating them for disease severity based on a scale of 1 to 5 in which 1 = no disease and 5 = dead plants. Cultivars most resistant to bacterial leaf spot (ratings in parentheses are averages of two tests and those followed by the same letter are not significantly different according to Tukey's Studentized Range Test, P = 0.05) were Green Bouquet (2.0 a), Piccolo (2.2 a), Mrs. Burn's Lemon (2.2 a), Genovese (2.4 a), and Dark Opal (2.5 ab). Moderately susceptible cultivars were Bush Green (2.8 abc), Sweet Basil (2.8 abc), Large Green (2.9 abcd), Lemon (3.1 abcd), and Mexican Spice (3.6 bcd). The most susceptible cultivars were Lettuce Leaved (3.8 cd), Thai (3.8 cd), Napoletano (4.0 de), Green Ruffles (5.0 e), and Purple Ruffles (5.0 e). Bacterial leaf spot of basil caused by P. cichorii was first reported in the U.S. from Florida (1). Other bacterial diseases reported on basil include leaf blight from Egypt caused by P. syringae (2) and leaf necrosis from California caused by P. viridiflava (3). This is the first report on the occurrence of basil bacterial leaf spot in Louisiana and the first reported information on cultivar susceptibility. References: (1) S. M. Burgess et al. Proc. Fla. State Hortic. Soc. 99:249, 1986. (2) S. A. M. El-Sadek et al. Assiut J. Agric. Sci. 22:2, 1991. (3) E. L. Little et al. Plant Dis. 78:831, 1994.

scholarly journals First Report of Pseudomonas cichorii Causing Bacterial Leaf Spot on Sweet Basil (Ocimum basilicum) in New Jersey

Plant Disease ◽  
2019 ◽  
Vol 103 (10) ◽  
pp. 2666-2666
Author(s):  
N. Patel ◽  
D. Y. Kobayashi ◽  
A. J. Noto ◽  
A. C. Baldwin ◽  
J. E. Simon ◽  
...  
Keyword(s):  
New Jersey ◽  
Leaf Spot ◽  
Ocimum Basilicum ◽  
Bacterial Leaf Spot ◽  
Pseudomonas Cichorii ◽  
First Report ◽  
Sweet Basil

scholarly journals First Report of Bacterial Leaf Spot Caused by Pseudomonas cichorii on Schefflera arboricola in Turkey

Plant Disease ◽  
2009 ◽  
Vol 93 (8) ◽  
pp. 848-848
Author(s):  
Y. Aysan ◽  
M. Mirik ◽  
F. Sahin
Keyword(s):  
Leaf Spot ◽  
Disease Incidence ◽  
Acid Methyl Ester ◽  
Identification System ◽  
Original Strain ◽  
Bacterial Leaf Spot ◽  
Pseudomonas Cichorii ◽  
First Report ◽  
Leaf Spots ◽  
Schefflera Arboricola

In late winter and spring of 2006 and 2008, leaf spots with yellow halos were observed on dwarf schefflera (Schefflera arboricola cvs. Gold Capella, Trinette, and Green Gold) that were grown as potted plants in two commercial ornamental greenhouses in Adana and Mersin, Turkey. Average disease incidence was assessed as 10% during the term of the study. Isolations were made from leaf spots symptoms on King's medium B. Bacteria consistently isolated from diseased tissues formed green fluorescent colonies on the medium. Ten representative bacterial strains were examined and found to be gram negative, rod shaped, and aerobic, levan, pectolytic, and arginine dihydrolase negative, and oxidase positive. They all induced a hypersensitive response in tobacco (Nicotiana tabacum cv. Samsun). All strains were identified as Pseudomonas cichorii with similarity indices of 79 to 99% based on fatty acid methyl ester (FAME) profiles determined by Sherlock Microbial Identification System software (TSBA 6 v. 6.00; Microbial ID, Newark, DE). Pathogenicity of the strains was confirmed on five dwarf schefflera plants by leaf tissue infiltration with bacterial suspensions (107 CFU ml–1) in sterile distilled water. P. cichorii NCPPB 3802 and sterile water were used as positive and negative controls, respectively. The same symptoms as those observed in the commercial greenhouses were observed on dwarf schefflera leaves within 12 to 15 days after inoculation. The bacteria were reisolated from the inoculated plants and identified as the same as the original strain by conventional tests and FAME analysis. Negative control plants remained disease free. Occurrence of bacterial leaf spot caused by P. cichorii on vegetable crops in Turkey (1,3) and dwarf schefflera in other countries (2) has been reported previously, but to our knowledge, this is the first report of the observation of P. cichorii on dwarf schefflera in Turkey. References: (1) Y. Aysan et al. Plant Pathol. 52:782. 2003. (2) A. R. Chase and D. D. Brunk. Plant Dis. 68:73, 1984. (3) F. Sahin et al. Acta Hortic. 695:93, 2005.

scholarly journals Bacterial Leaf Spot of Zinnia Caused by Xanthomonas campestris pv. zinniae, a New Disease in Korea

Plant Disease ◽  
2012 ◽  
Vol 96 (7) ◽  
pp. 1064-1064 ◽  
Author(s):  
I.-S. Myung ◽  
J. Y. Lee ◽  
H. L. Yoo ◽  
J. M. Wu ◽  
H.-S. Shim
Keyword(s):  
Leaf Spot ◽  
Xanthomonas Campestris ◽  
Negative Control ◽  
Gyrb Gene ◽  
23S Rrna ◽  
Distilled Water ◽  
Bacterial Leaf Spot ◽  
Field Isolates ◽  
Sequence Identity ◽  
Physiological Tests

In September 2011, bacterial leaf spot was observed on zinnia plants (Zinnia elegans L.) grown in a garden in Suwon, Korea. Leaf symptoms included angular lesions that were yellow or brown-to-reddish brown in the center. Bacterial isolates (BC3293 to BC3299) were recovered on trypticase soy agar from lesions surface-sterilized in 70% ethyl alcohol for 1 min. Pathogenicity of the isolates was confirmed by spray inoculation with a bacterial suspension (106 CFU/ml) prepared in sterile distilled water and applied to zinnia plants at the four- to five-leaf growth stage (two plants per isolate). Sterile distilled water was used as the negative control. The inoculated plants were incubated in a greenhouse at 26 to 30°C and 95% relative humidity. Characteristic leaf spot symptoms developed on inoculated zinnia plants 5 days after inoculation. No symptoms were observed on the negative control plants. The bacterium reisolated from the inoculated leaves was confirmed through gyrB gene sequence analysis (3). All isolates were gram-negative, aerobic rods, each with a single flagellum. Isolates were positive for catalase and negative for oxidase. The biochemical and physiological tests for differentiation of Xanthomonas were performed using methods described by Shaad et al. (2). The isolates were positive for mucoid growth on yeast extract-dextrose-calcium carbonate agar, growth at 35°C, hydrolysis of starch and esculin, protein digestion, acid production from arabitol, and utilization of glycerol and melibiose. Colonies were negative for ice nucleation, and alkaline in litmus milk. The gyrB gene (870 bp) and the 16S-23S rRNA internal transcribed spacer (ITS) regions (884 bp) were sequenced to aid in identification of the original field isolates using published PCR primer sets Xgyr1BF/Xgyr1BR (3) and A1/B1 (1), respectively. Sequence of the gyrB gene (GenBank Accession Nos. JQ665732 to JQ665738) from the zinnia field isolates shared 100% sequence identity with the reference strain of Xanthomonas campestris pv. zinniae (GenBank Accession No. EU285210), and the ITS sequences (GenBank Accession Nos. JQ665725 to JQ665731) had 99.9% sequence identity with X. campestris pv. zinnia XCZ-1 (GenBank Accession No. EF514223). On the basis of the pathogenicity assays, biochemical and physiological tests, and sequence analyses, the isolates were identified as X. campestris pv. zinniae. To our knowledge, this is the first report of bacterial leaf spot of zinnia caused by X. campestris pv. zinniae in Korea. The disease is expected to result in economic and aesthetic losses to plants in Korean landscapes. Thus, seed treatment with bactericides will be required to control the bacterial leaf spot of zinnia before planting. References: (1) T. Barry et al. The PCR Methods Appl. 1:51, 1991. (2) N. W. Schaad et al. Page 189 in: Laboratory Guide for Identification of Plant Pathogenic Bacteria. 3rd ed. N. W. Schaad et al., eds. The American Phytopathological Society, St. Paul, MN, 2001. (3) J. M. Young et al. Syst. Appl. Microbiol. 31:366, 2008.

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