scholarly journals First Report of Bacterial Leaf Spot of Basil Caused by Pseudomonas viridiflava in Argentina

Plant Disease ◽  
1999 ◽  
Vol 83 (9) ◽  
pp. 876-876 ◽  
Author(s):  
A. M. Alippi ◽  
S. Wolcan ◽  
E. Dal Bó
Keyword(s):  
Leaf Spot ◽  
Disease Incidence ◽  
Tween 80 ◽  
Pathogenic Fungi ◽  
Soft Rot ◽  
Bacterial Leaf Spot ◽  
First Report ◽  
Arginine Dihydrolase ◽  
Pseudomonas Viridiflava ◽  
Physiological Tests

In June 1998, during a cool, humid period, typical bacterial spot symptoms were observed on basil plantlets (Ocimun basilicum L. ‘Royal Louis’ and ‘Zaes’) in a commercial greenhouse in La Plata, Argentina. Affected plants had dark brown to black lesions on cotyledons. Spots on leaves were first water soaked, then became necrotic and progressed inward from the margins. Disease incidence approached 30%. Symptoms were similar to those reported by Little et al. (2) on basil affected by Pseudomonas viridiflava. No pathogenic fungi or viruses were associated with symptomatic plants. Bacterial streaming was observed from lesion margins. Bacteria consistently isolated from leaf lesions formed cream-colored, glistening, convex colonies on sucrose peptone agar and a green fluorescent pigment on King's medium B. Bacterial growth produced a distinctive olive green pigment on glycerol agar medium and a pink pigment on T-5 medium (1). Four isolates selected for further study were aerobic, Gram-negative, non-spore-forming rods. In LOPAT (levan-oxidase-potato rot-arginine dihydrolase-tobacco hypersensitivity) tests, all induced a hypersensitive response in tobacco plants, caused soft rot of potato tubers, and were negative for levan, oxidase, and arginine dihydrolase. In addition, strains rotted onion slices and produced a reddish sunken lesion on bean pods. Acid was produced aerobically from D-glucose, mannitol, mesoinositol and sorbitol, but not from D-arabinose, L-rhamnose, melibiose, amygdalin, or sucrose. Bacteria used D-tartrate, pyruvate, and citrate, but not benzoate. The strains did not hydrolyze starch, exhibited an oxidative metabolism of glucose, and did not reduce nitrates to nitrites or accumulate poly-β-hydroxybutyrate inclusions. Negative reactions were obtained with indole, ornithine, and D-tryptophan. Isolates hydrolyzed gelatine, used Tween 80, were positive for catalase, and were unable to grow in the presence of 5% NaCl. Colonies developed at 4°C but not 37°C. Reactions were identical to those of reference strains ICMP 5776 and 12363, which were included in all tests for comparison. Pathogenicity was verified on 35-day-old basil plants by both spraying and infiltration inoculations with bacterial suspensions (108 and 105 cells per ml, respectively). Carborundum was included in the inoculum used for a set of plants inoculated by spraying. Controls were injected or sprayed (with and without Carborundum) with sterile, distilled water. In addition, bean (Phaseolus vulgaris cv. Nag12 INTA) and lettuce (Lactuca sativa cv. criolla), both reported as host plants, were inoculated by spraying with bacterial suspensions of 107 cells per ml plus Carborundum. After 48 h in a humid chamber, inoculated plants and controls were maintained at 23 ± 3°C. Symptoms on basil plants inoculated by injection or spraying with Carborundum were identical to those observed on basil in the field. Symptoms on bean and lettuce were similar to those described for P. viridiflava. The bacterium was reisolated from lesions of all species tested, fulfilling Koch's postulates. No lesions were observed on controls or on plants sprayed without Carborundum, suggesting that bacteria gain entry through wounds. The microorganism was identified by physiological tests and polymerase chain reaction as P. viridiflava. This is the first report of bacterial leaf spot of basil in Argentina. References: (1) R. Gitaitis et al. Plant Dis. 81:897, 1997. (2) E. L. Little et al. Plant Dis. 78:831, 1994.

scholarly journals First Report of Bacterial Leaf Spot of Basil Caused by Pseudomonas viridiflava in Hungary

Plant Disease ◽  
2012 ◽  
Vol 96 (1) ◽  
pp. 141-141 ◽  
Author(s):  
A. Végh ◽  
M. Hevesi ◽  
Zs. Némethy ◽  
L. Palkovics
Keyword(s):  
Leaf Spot ◽  
Sequence Similarity ◽  
Soft Rot ◽  
Hypersensitive Reaction ◽  
Bacterial Suspension ◽  
Bacterial Leaf Spot ◽  
Biochemical Tests ◽  
First Report ◽  
Arginine Dihydrolase ◽  
Pseudomonas Viridiflava

In April 2011, typical bacterial spot symptoms were observed on sweet basil plantlets (Ocimum basilicum L.) in a supermarket in Budapest, Hungary. Affected plants had dark brown-to-black lesions on the cotyledons. Spots on the leaves were first water soaked and then became necrotic and progressed inward from the margins. Symptoms were similar to those reported by Little et al. (3) on basil affected by Pseudomonas viridiflava. Bacteria consistently isolated from leaf lesions formed mucoid colonies with a green fluorescent pigment on King's B medium. Strains were gram negative. In LOPAT (levan-oxidase-potato rot-arginine dihydrolase-tobacco hypersensitivity) tests (2), all induced a hypersensitive reaction (HR) in tobacco (Nicotiana tabacum L. cv. White Burley) leaves (1), caused soft rot of potato tuber slices, and were negative for levan, oxidase, and arginine dihydrolase. Biochemical tests, API 20NE and API 50 CH (Biomérieux, Marcy l'Etoile, France), were also used for identification. The pathogenicity of three isolates was tested twice by injecting 20-day-old healthy basil plants with a bacterial suspension (107 CFU/ml). Controls were injected with sterile distilled water. Plants were kept at 25 to 28°C and 80 to 100% relative humidity. Forty-eight hours after inoculation, dark brown-to-black lesions were observed only on inoculated plants. The bacterium was reisolated from lesions of all plants tested, fulfilling Koch's postulates. No lesions were observed on controls. To identify the pathogen, a PCR technique was used. The 16SrDNA region was amplified with general bacterial primer pair (63f forward and 1389r reverse) (4) then the PCR products were cloned into Escherichia coli DH5α cells and a recombinant plasmid was sequenced by M13 forward and reverse primers. The sequence was deposited in GenBank (Accession No. HE585219). On the basis of the symptoms, biochemical tests, and 16SrDNA sequence homology (99% sequence similarity with a number of P. viridiflava isolates), the pathogen was identified as P. viridiflava. To our knowledge, this is the first report of bacterial leaf spot of basil in Hungary, which can seriously affect the basil production. References: (1) Z. Klement. Nature 199:299, 1963. (2) R. A. Lelliot et al. Appl. Bacteriol. 29:470, 1966. (3) E. L. Little et al. Plant Dis. 78:831, 1994. (4) A. M. Osborn et al. Environ. Microbiol. 2:39, 2000.

scholarly journals First report of bacterial leaf spot on calla lily (Zantedeschia spp.) caused by Pseudomonas viridiflava in Iran

2019 ◽  
Vol 101 (2) ◽  
pp. 393-393
Author(s):  
Esmaeil Basavand ◽  
Pejman Khodaygan ◽  
Heshmatollah Rahimian
Keyword(s):  
Leaf Spot ◽  
Bacterial Leaf Spot ◽  
First Report ◽  
Calla Lily ◽  
Pseudomonas Viridiflava

scholarly journals First Report of Pseudomonas viridiflava as the Causal Agent of Bacterial Leaf Spot of Mexican Heather in California

Plant Disease ◽  
2018 ◽  
Vol 102 (12) ◽  
pp. 2633 ◽  
Author(s):  
S. Albu ◽  
M. Lai ◽  
P. W. Woods ◽  
L. B. Kumagai
Keyword(s):  
Leaf Spot ◽  
Causal Agent ◽  
Bacterial Leaf Spot ◽  
First Report ◽  
Pseudomonas Viridiflava

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 Leaf Spot of Dieffenbachia picta and Aglaonema commutatum Caused by Burkholderia gladioli in Argentina

Plant Disease ◽  
2009 ◽  
Vol 93 (5) ◽  
pp. 550-550 ◽  
Author(s):  
A. M. Alippi ◽  
A. C. López
Keyword(s):  
Burkholderia Cepacia ◽  
Disease Incidence ◽  
Soft Rot ◽  
Distilled Water ◽  
First Report ◽  
Burkholderia Gladioli ◽  
Sterile Needle ◽  
Pcr Products ◽  
Humidity Chamber ◽  
Physiological Tests

During May of 2008 (austral autumn), an uncharacterized disease was observed on Dieffenbachia picta (Lodd.) Schott and Aglaonema commutatum Schott in commercial greenhouses in Pontevedra (34°45′6″S, 58°42′42″W), Argentina. Affected plants showed irregular, brown lesions on leaves, approximately 15 to 20 mm in diameter, surrounded by water-soaked haloes that progressed inward from the margins. Water-soaked rotting symptoms were also observed in petioles. Disease incidence approached 80%. Abundant bacterial streaming was observed from lesions when examined at ×100. Bacteria consistently isolated from lesions formed cream-colored, glistening, convex colonies on sucrose peptone agar and produced a yellowish green, diffusible, nonfluorescent pigment on King's medium B. Four isolates from different symptomatic plants were selected for further study. All were aerobic, gram-negative rods that accumulated poly-β-hydroxybutyrate inclusions. In LOPAT tests, all induced a hypersensitive response in tobacco plants, caused soft rot of potato tubers, and were positive for levan, negative for arginine dihydrolase, and variable for oxidase. All isolates oxidized glucose, did not hydrolyze starch and were able to rot onion slices. Colonies developed at 41°C but not at 4°C. With the API 20NE test strips and database (bioMerieux, Buenos Aires, Argentina), all isolates matched (99% identity) Burkholderia cepacia, but their inability to metabolize cellobiose and sucrose further identified them as B. gladioli. For molecular identification, 23S rDNA was amplified by PCR using B. gladioli-specific primers LP1 and LP4, which yielded a 700-bp product (3), and PCR-restriction fragment length polymorphism of 16S rDNA using AluI (2). PCR products were identical to those from the type strain for B. gladioli, ICMP 3950, isolated from Gladiolus spp. that had been included in all tests for comparison. Pathogenicity was verified on D. picta and A. commutatum by spraying the plants with bacterial suspensions in sterile distilled water at 108 CFU/ml with and without wounding the leaves with a sterile needle and also by injection-infiltration of bacterial suspensions at 105 CFU/ml. In addition, another host plant, Gladiolus communis L., was inoculated in the same manner. Controls were sprayed or infiltrated with sterile distilled water. After 48 h in a humidity chamber, plants were kept at 25 ± 3°C in a greenhouse. In all hosts, symptoms were first detected 3 days after inoculation and lesions expanded to resemble natural infections within 4 to 7 days. All strains caused necrosis around the inoculation sites and lesions were identical to those induced by the ICMP reference strain. Bacteria were reisolated from each host tested and then the original and reisolated strains were compared by enterobacterial repetitive intergeneric consensus-PCR (1); DNA fingerprints of the reisolated strains were identical to those of the original strains, thereby fulfilling Koch's postulates. No lesions were observed on controls or on plants inoculated by spraying without wounding, suggesting that bacteria gain entry through wounds. On the basis of PCR and physiological tests the pathogen was identified as B. gladioli (2–4). To our knowledge, this is the first report of B. gladioli on Dieffenbachia and Aglaonema spp. References: (1) F. J. Louws et al. Appl. Environ. Microbiol. 60:2286, 1994. (2) C. Van Pelt et al. J. Clin. Microbiol. 37:2158, 1999. (3) P. W. Whitby et al. J. Clin. Microbiol. 38:282, 2000. (4) E. Yabuuchi et al. Microbiol. Immunol. 36:1251, 1992.

First Report of Bacterial Leaf Spot Caused by Pseudomonas viridiflava on Chinese Cabbage in China

Plant Disease ◽  
2019 ◽  
Vol 103 (7) ◽  
pp. 1764-1764 ◽  
Author(s):  
Y. Liu ◽  
X. Y. Guan ◽  
X. D. Kong ◽  
X. L. Wu ◽  
S. N. Liu ◽  
...  
Keyword(s):  
Chinese Cabbage ◽  
Leaf Spot ◽  
Bacterial Leaf Spot ◽  
First Report ◽  
Pseudomonas Viridiflava

scholarly journals First report of Colletotrichum fructicola and Colletotrichum nymphaeae causing leaf spot on Rubus corchorifolius in Zhejiang province, China

Plant Disease ◽  
2021 ◽  
Author(s):  
Ju Wu ◽  
Hanrong Wang ◽  
Li Fang ◽  
Yunye Xie ◽  
Lianping Wang
Keyword(s):  
Leaf Spot ◽  
Type Strain ◽  
Disease Incidence ◽  
Morphological Characteristics ◽  
Pathogenic Fungi ◽  
Zhejiang Province ◽  
Colletotrichum Acutatum ◽  
Leaf Spot Disease ◽  
Conidial Suspension ◽  
First Report

Rubus corchorifolius is one of the most economically important fruit trees, (Tian et al. 2021). A severe leaf spot disease on leaves of R. corchorifolius was observed in Longquan county, Zhejiang province (118°42’E, 27°42’N) in 2019, with disease incidence of more than 20% on affected plants. The symptoms on leaves of the naturally affected plants were early necrotic lesion with white centers, surrounded by yellow halos (< 5 mm). Later, lesions were expanded with yellowish-brown centers, surrounded by yellow halos (< 5 mm). Putative pathogenic fungi were isolated as described by Fang (1998) and two pure single-colony fungal strains (FPZ1 and FPZ2) were selected for further analysis. The fungi was cultured on potato dextrose agar (PDA) medium for 6 days, at 25°C. The colonies had gray-green centers, white aerial mycelium and gelatinous orange conidial masses. The conidia were unicellular, smooth-walled, hyaline, cylindrical with obtuse to rounded ends, the size 10.15 to 14.09 µm (mean = 12.95 µm, n = 50) × 4.36 to 6.19 µm (mean = 5.19 µm, n = 50) were single, brown to dark brown, ovoid or irregular in shape, and 5.59 to 12.99 µm (mean = 8.77 µm, n = 50) × 4.68 to 10.36 µm (mean = 6.50 µm, n = 50). The characteristics of FPZ1 were consistent with the description of species in the Colletotrichum gloeosporioides complex (Weir et al. 2012). The conidia of FPZ2 were hyaline, smooth-walled, one-celled, fusiform, the size 9.34 to 14.09 µm (mean = 11.92 µm, n = 50) × 3.26 to 6.15 µm (mean = 4.89 µm, n = 50). Appressoria were single, darker brown, elliptical or irregular in outline, and 4.49 to 15.06 µm (mean = 9.88 µm, n = 50) × 3.23 to 7.42 µm (mean = 5.72 µm, n = 50) in size. The characteristics of FPZ2 were consistent with species of the Colletotrichum acutatum complex (Damn et al. 2012). For molecular identification of strains, the internal transcribed spacer (ITS), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), beta-tubulin (TUB), chitin synthase (CHS-1), and actin (ACT) genes were sequenced (Weir et al. 2012). For the strain FPZ1, the five sequences obtain were deposited in GenBank (MT846907, MT849313, MT849317, MT849315 and MT849319, respectively). A BLAST search of FPZ1 sequences showed 99% identity with the five loci sequences of type strain C. fructicola ICMP 18581 (JX010165, JX010033, JX010405, JX009866 and FJ907426) (Jayawardena et al. 2016). Similarly, for the strain FPZ2, the five sequences (MT846885, MT849314, MT849318, MT849316 and MT849320, respectively) had 99% identity with the five loci sequences of type strain C. nymphaeae CBS 515.78 (JQ948197, JQ948527, JQ949848, JQ948858 and JQ949518, respectively) (Jayawardena et al. 2016). Based on morphological characteristics and phylogenetic analysis, FPZ1 was identified as C. fructicola and FPZ2 as C. nymphaeae, respestively. For pathogenicity tests, 10 μL conidial suspension (1 × 106 conidia per ml) of FPZ1 was used to inoculate five healthy, non-wounded detached leaves, while five leaves inoculated with sterilized water served as control. The experiment was repeated three times, and all leaves were kept on a mist bench at 27°C and relative humidity 80% for 6 days. The inoculation sites of both FPZ1 and FPZ2 became brown and necrotic, while control leaves developed no symptoms. C. fructicola and C. nymphaeae were re-isolated from the lesions of inoculated leaves, fulfilling Koch’s postulates. To our knowledge, this is the first report of C. fructicola and C. nymphaeae causing leaf spot on Rubus corchorifolius in China, and reports on the prevalence of C. gloeosporioides and C. acutatum species complexes will be beneficial to management of anthracnose in R. corchorifolius.

scholarly journals First Report of Stemphylium botryosum on Spinach in Texas

Plant Disease ◽  
2010 ◽  
Vol 94 (11) ◽  
pp. 1377-1377 ◽  
Author(s):  
J. D. Reed ◽  
J. E. Woodward ◽  
K. L. Ong ◽  
M. C. Black ◽  
L. A. Stein
Keyword(s):  
Leaf Spot ◽  
Spinacia Oleracea ◽  
Disease Incidence ◽  
Morphological Characteristics ◽  
Tween 80 ◽  
Growing Season ◽  
Control Treatment ◽  
Infected Leaf ◽  
First Report ◽  
Stemphylium Botryosum

During the 2009 to 2010 growing season, symptoms of an unknown leaf spot were observed on spinach (Spinacia oleracea L.) in production fields in southwest Texas. Approximately 500 ha were affected, especially cvs. Rakaia and Viceroy. Disease incidence was 30 and 2% for Rakaia and Viceroy, respectively. Diseased plants exhibited small (1 to 3 mm in diameter), tan, necrotic lesions with a circular to oval shape and were void of any signs of a pathogen. Symptomatic leaves were surface sterilized in 1.5% NaOCl for 1 min, rinsed with sterile water, and air dried. Leaf sections (~1 cm2) were cut and placed on acidified potato dextrose agar (APDA), or APDA supplemented with streptomycin (SAPDA). Fungal mycelia growing from the edges of infected leaf sections were transferred to PDA and incubated at 25°C with a 12-h/12-h light/dark cycle. After 14 days of incubation, dark brown mycelia giving rise to unbranched conidiophores bearing brown, deeply septate, ovoid conidia were observed. Conidia measured 16.8 to 27.3 × 13.1 to 19.6 μm. On the basis of these morphological characteristics, the fungus was identified as Stemphylium botryosum (3). Cultures were transferred to clarified V8 juice agar to obtain inoculum for pathogenicity tests. Eight-week-old plants (n = 20) of spinach cvs. Hybrid 310, Wintergreen, Ashley, and Rakaia were sprayed until runoff with a suspension containing 0.001% Tween 80 and 1 × 104 conidia/ml. Noninoculated plants served as a control treatment. Plants were placed in a growth chamber and incubated in the dark at 25°C and 95% relative humidity. Following 36 h of incubation, plants were transferred to a plastic enclosure and maintained at 23 ± 4°C. After 7 to 10 days, tan, oval-shaped lesions were observed on all inoculated spinach plants. All control plants, with the exception of Rakaia, failed to develop symptoms. Isolates of S. botryosum were recovered on SAPDA from symptomatic leaves, confirming Koch's postulates. Previous reports have shown that S. botryosum can be transmitted from infected seed (1), thus, additional plants of each cultivar (n = 36) were grown in the greenhouse to determine the potential for seedborne contamination. After 8 weeks, leaf spot symptoms identical to those observed on the original plants developed on 75% of the Rakaia plants, while symptom development on the other cultivars was negligible. Isolates of S. botryosum were only recovered from symptomatic Rakaia leaves. Similar field observations were made during the 2001 to 2002 growing season; however, attempts to isolate S. botryosum in that season were unsuccessful. Recent outbreaks of Stemphylium leaf spot have been reported in Arizona (4), California (3), Delaware and Maryland (2), and Washington (1). To our knowledge, this is the first report of S. botryosum on spinach in Texas. While the origin of inoculum causing the disease in Texas is unknown, S. botryosum may have been seedborne (2). The implementation within the past few years of very high density plantings of spinach (1.9 to 3.7 million seeds/ha) may lead to an increase in incidence and severity of this disease in Texas. References: (1) L. J. du Toit and M. L. Derie. Plant Dis. 85:920, 2001. (2) K. L. Everts and D. K. Armentrout. Plant Dis. 85:1209, 2001. (3) S. T. Koike et al. Plant Dis. 85:126, 2001. (4) S. T. Koike et al. Plant Dis. 89:1359, 2005.

scholarly journals First report on Pseudomonas viridiflava causing bacterial leaf spot of curly lettuce in Turkey

2018 ◽  
Vol 100 (1) ◽  
pp. 121-121
Author(s):  
Hasan Murat Aksoy ◽  
Murat Ozturk ◽  
Neslihan Kilic
Keyword(s):  
Leaf Spot ◽  
Bacterial Leaf Spot ◽  
First Report ◽  
Pseudomonas Viridiflava

scholarly journals First Report of Bacterial Leaf Spot Caused by Xanthomonas campestris pv. olitorii on Jute Grown for Seed in India

Plant Disease ◽  
2013 ◽  
Vol 97 (8) ◽  
pp. 1109-1109
Author(s):  
C. Biswas ◽  
P. Dey ◽  
A. Bera ◽  
S. Satpathy ◽  
B. S. Mahapatra
Keyword(s):  
Bacterial Strain ◽  
Leaf Spot ◽  
Xanthomonas Campestris ◽  
Disease Incidence ◽  
Negative Control ◽  
Nutrient Agar ◽  
Distilled Water ◽  
Bacterial Leaf Spot ◽  
First Report ◽  
Pure Cultures

Jute (Corchorus olitorius L.) is the second most important fiber crop after cotton in terms of global production (3). In November 2011, symptoms suggestive of bacterial infection were observed on a seed crop of jute at the CRIJAF research farm, Barrackpore, West Bengal, India. The disease appeared as small, brown, circular spots, usually less than 5 mm in diameter on the leaves and some of the spots were surrounded by a yellow halo. The lesions on the stems were elongated and in some cases were found to girdle the stem. In the later stages of disease, brown sunken spots were found on the green capsules. Disease incidence varied from about 20% to 90% of the total plants in different affected fields at the CRIJAF research farm. Bacterial leaf spot of jute with similar symptoms was reported in 1957 from Sudan (4). Five symptomatic and three asymptomatic leaf samples were collected from different jute fields. Bacterial colonies isolated on nutrient agar medium from infected young leaves were Xanthomonas-like and pale yellow cream in color. Total DNA was extracted from symptomatic as well as asymptomatic leaf samples by using an improved salt concentration and simple sodium acetate CTAB method (2). Single bacterial colonies were transferred to nutrient agar (NA) medium plates and incubated at 28°C for 48 h. Pure colonies from plates were used directly for DNA extraction using the QIAGEN DNeasy Blood and Tissue kit. PCR was carried out with Xanthomonas campestris specific primers NZ8F3/NZ85R3 (1), which generated an amplicon of 530 bp from all the symptomatic leaf samples as well as pure cultures of the isolated bacteria. No amplification was obtained from asymptomatic leaves. The amplicons from the five symptomatic samples collected from the field were sequenced and showed 100% identity with one another, and one sequence (strain JB-CO-13) was deposited in GenBank (Accession No. KC342185). The BLASTn analysis revealed that bacterial strain JB-CO-13 had 100% identity with X. campestris pv. olitorii (EU285213). Nucleotide span and ORF finder (NCBI) analysis indicated the 530-bp PCR amplicon coded part of a gyrase B gene that had 100% identity with a translated gene product (Protein ID: ABX84334). Three leaves of five 1-month-old jute plants (cv. JRO 204) in pot culture were infiltrated each with a separate bacterial strain using suspensions (1 × 105 CFU/ml) in distilled water. The negative control consisted of leaves infiltrated with sterile distilled water. The plants were kept in a greenhouse with mean maximum and minimum temperatures of 28.96 and 21.8°C, respectively. The plants were covered with plastic bags to maintain high relative humidity (>80%). Typical bacterial lesions were recorded on all the inoculated plants after 1 week. No lesions were seen on the negative control. To the best of our knowledge, this is the first report of bacterial leaf spot on C. olitorius caused by X. campestris pv. olitorii from India. References: (1) J. Adriko et al. Plant Pathol. 61:489, 2012. (2) C. Biswas, et al. Lett. Appl. Microbiol. 56:105, 2013. (3) Food and Agriculture Organization of the United Nations. Agricultural Commodities: Profiles and Relevant WTO Negotiating Issues. Online: http://www.fao.org/docrep/006/Y4343E/y4343e03.htm , 2003. (4) K. A. Sabet. Ann. Appl. Biol. 45:516, 1957.

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