scholarly journals Bacterial Blight of Leek: A New Disease in California Caused by Pseudomonas syringae

Plant Disease ◽  
1999 ◽  
Vol 83 (2) ◽  
pp. 165-170 ◽  
Author(s):  
Steven T. Koike ◽  
Jeri D. Barak ◽  
Diana M. Henderson ◽  
Robert L. Gilbertson
Keyword(s):  
Fatty Acid ◽  
Pseudomonas Syringae ◽  
Fatty Acid Analysis ◽  
Pcr Analysis ◽  
Allium Porrum ◽  
Fluorescent Pseudomonad ◽  
Rdna Sequencing ◽  
Plant Densities ◽  
Pathogenicity Tests ◽  
Physiological Tests

During 1996 and 1997, a new and damaging disease of leek (Allium porrum) was observed on greenhouse-produced transplants and field-grown plants in California. Symptoms were water-soaked lesions at leaf tips, which eventually expanded down the length of the leaf and resulted in brown, elongated, stripe-like lesions with yellow margins. Diseased leaves eventually wilted. A blue fluorescent pseudomonad was consistently recovered from lesions, and biochemical and physiological tests indicated that it was Pseudomonas syringae. Pathogenicity tests established that representative strains of this P. syringae induced disease symptoms in leek that were similar to those observed on leek plants in the greenhouse and field, and that this bacterium caused similar symptoms in onion, chives, and garlic plants. Representative strains were further characterized by fatty acid analysis, repetitive bacterial sequence-polymerase chain reaction (rep-PCR), and rDNA sequencing. Fatty acid analysis confirmed that these isolates were P. syringae, but did not provide a clear pathovar designation. Rep-PCR analysis revealed that all the California leek P. syringae strains had identical DNA fingerprints and that these strains were indistinguishable from those of known strains of P. syringae pv. porri. In addition, the rDNA sequence of the spacer region between 16S and 23S rDNA genes was identical among the California leek P. syringae strains and P. syringae pv. porri. Together, these results established that the new leek disease in California is caused by P. syringae pv. porri. P. syringae pv. porri was recovered from a commercial leek seed lot imported into California, which suggests that the pathogen was introduced in association with seed. Commercial leek production in California is favorable for development of this disease because transplants are produced in greenhouses with high plant densities, overhead irrigation, and mowing of plants.

scholarly journals Bacterial Gall of Loropetalum chinense caused by Pseudomonas amygdali pv. loropetali pv. nov.

Plant Disease ◽  
2018 ◽  
Vol 102 (4) ◽  
pp. 799-806 ◽  
Author(s):  
Carrie Lapaire Harmon ◽  
Sujan Timilsina ◽  
John Bonkowski ◽  
Debra D. Jones ◽  
Xiaoan Sun ◽  
...  
Keyword(s):  
Fatty Acid ◽  
16S Rrna ◽  
Pseudomonas Syringae ◽  
Housekeeping Genes ◽  
Fatty Acid Analysis ◽  
Fluorescent Pseudomonad ◽  
Molecular Tests ◽  
Stem Gall ◽  
Pathogenicity Tests ◽  
Olive Industry

In 2012, stem gall samples on Loropetalum chinense were sent to Florida diagnostic labs from Alabama and Florida nurseries. A fluorescent pseudomonad was consistently isolated from the galls. The organism was originally identified in Alabama based on 16S rRNA sequencing as Pseudomonas savastanoi, which causes a production-limiting disease of olive. The loropetalum strains and reference strains were compared using LOPAT, Biolog, fatty acid analysis, multilocus sequence analysis (MLSA), and pathogenicity tests. The LOPAT tests placed the loropetalum strains within Pseudomonas syringae. Biolog and fatty acid analysis placed the strains in various pathovars of P. syringae and P. savastanoi, respectively. MLSA of a set of housekeeping genes separated the loropetalum strains from the olive knot-inducing strains. Our work indicates there is a need to use more tests than 16S rRNA to accurately diagnose new bacterial diseases. In pathogenicity tests, the loropetalum strains produced galls only on loropetalum, but not on olive, mandevilla, or almond, indicating this strain is not a threat to the olive industry. Based on the pathogenicity assays and molecular tests, loropetalum strains represent a distinct and new pathovar, P. amygdali pv. loropetali pv. nov., for which the strain PDC13-208 (= DSMZ 105780PT) has been designated as the pathotype strain.

scholarly journals Identification of Bacteria Infecting Seedlings of Mung Bean Used in Rooting Bioassays

1991 ◽  
Vol 116 (1) ◽  
pp. 80-84 ◽  
Author(s):  
R.R. Tripepi ◽  
M.W. George
Keyword(s):  
Electron Microscopy ◽  
Pseudomonas Syringae ◽  
Mung Bean ◽  
Fatty Acid Analysis ◽  
Routine Procedure ◽  
Cupric Acetate ◽  
Seedborne Pathogens ◽  
Pathogenicity Tests ◽  
Identification Of Bacteria ◽  
Physiological Tests

Seeds of `Berken' mung bean [Vigna radiata (L.) R. Wilcz.] were surface-sterilized with NaOCl and then either aerated 24 hours before sowing (routine procedure), planted immediately after the NaOCl treatment, or treated with hot cupric acetate and antibiotics before planting. Nine- or 10-day-old seedlings were used in rooting bioassays. Up to 10% of the seedlings and 17% of the cuttings had collapsed upper stems or wilted leaves. None of the seed treatments completely eliminated the pathogen, but the combination of hot cupric acetate plus antibiotics reduced the quantity of diseased cuttings to 3.3%. A white and two yellow-pigmented (Y1 and Y2) bacteria were isolated from diseased cuttings and used in subsequent pathogenicity tests. The Y2 strain was nonpathogenic. Stems of plants inoculated with the white strain turned brown and collapsed 2 days after inoculation, whereas leaves of plants inoculated with the Y1 strain wilted after 7 days. Electron microscopy, fatty acid analysis, and standard biochemical and physiological tests were used to identify the white strain as Pseudomonas syringae pv. syringae van Hall and the Y1 strain as Curtobacterium flaccumfaciens ssp. flaccumfaciens (Hedges) Collins and Jones. These results emphasize that seeds of mung bean should be checked for seedborne pathogens to avoid experimental artifacts.

scholarly journals First Report of Bacterial Leaf Spot of Swiss Chard Caused by Pseudomonas syringae pv. aptata in California

Plant Disease ◽  
2003 ◽  
Vol 87 (11) ◽  
pp. 1397-1397 ◽  
Author(s):  
S. T. Koike ◽  
D. M. Henderson ◽  
C. T. Bull ◽  
P. H. Goldman ◽  
R. T. Lewellen
Keyword(s):  
Fatty Acid ◽  
Sugar Beet ◽  
Pseudomonas Syringae ◽  
Leaf Spot ◽  
Nutrient Broth ◽  
Pcr Analysis ◽  
Bacterial Leaf Spot ◽  
First Report ◽  
Leaf Spots ◽  
Swiss Chard

From 1999 through 2003, a previously unreported disease was found on commercial Swiss chard (Beta vulgaris subsp. cicla) in the Salinas Valley, (Monterey County) California. Each year the disease occurred sporadically throughout the long growing season from April through September. Initial symptoms were water-soaked leaf spots that measured 2 to 3 mm in diameter. As disease developed, spots became circular to ellipsoid, 3 to 8 mm in diameter, and tan with distinct brown-to-black borders. Spots were visible from the adaxial and abaxial sides. Cream-colored bacterial colonies were consistently isolated from spots. Strains were fluorescent on King's medium B, levan positive, oxidase negative, and arginine dihydrolase negative. Strains did not rot potato slices but induced a hypersensitive reaction on tobacco (Nicotiana tabacum cv. Turk). The isolates, therefore, belong in LOPAT group 1 (1). Fatty acid methyl esters (FAME) analysis (MIS-TSBA version 4.10, MIDI Inc., Newark, DE) gave variable results that included Pseudomonas syringae, P. cichorii, and P. viridiflava with similarity indices ranging from 0.91 to 0.95. BOX-polymerase chain reaction (PCR) analysis gave identical banding patterns for the chard isolates and for known P. syringae pv. aptata strains, including the pathotype strain CFBP1617 (2). The bacteria were identified as P. syringae. Pathogenicity of 11 strains was tested by growing inoculum in nutrient broth shake cultures for 48 h, diluting to 10 × 6 CFU/ml, and spraying onto 5-week-old plants of Swiss chard cvs. Red, White, Silverado, and CXS2547. Untreated control plants were sprayed with sterile nutrient broth. After 7 to 10 days in a greenhouse (24 to 26°C), leaf spots similar to those observed in the field developed on all inoculated plants. Strains were reisolated from the spots and identified as P. syringae. Control plants remained symptomless. To investigate the host range of this pathogen, the same procedures were used to inoculate three strains onto other Chenopodiaceae plants: five cultivars of sugar beet (B. vulgaris), and one cultivar each of spinach (Spinacia oleracea) and Swiss chard. In addition, five chard strains and strain CFBP1617 were inoculated onto two cultivars of sunflower (Helianthus annuus), and one cultivar each of cantaloupe (Cucumis melo), sugar beet, spinach, and Swiss chard. All Swiss chard, cantaloupe, sunflower, and sugar beet plants developed leaf spots after 7 days. The pathogen was reisolated from spots and confirmed to be the same bacterium using BOX-PCR analysis. Spinach and untreated controls failed to show symptoms. All inoculation experiments were done at least twice and the results were the same. The phenotypic data, fatty acid and genetic analyses, and pathogenicity tests indicated that these strains are P. syringae pv. aptata. To our knowledge this is the first report of bacterial leaf spot of commercially grown Swiss chard in California caused by P. syringae pv. aptata. The disease was particularly damaging when it developed in Swiss chard fields planted for “baby leaf” fresh market products. Such crops are placed on 2-m wide beds, planted with high seed densities, and are sprinkler irrigated. This disease has been reported from Asia, Australia, Europe, and other U.S. states. References: (1) R. A. Lelliott et al. J. Appl. Bacteriol. 29:470, 1966. (2) J. L. W. Rademaker et al. Mol. Microbiol. Ecol. Man. 3.4.3:1–27, 1998.

scholarly journals Dietary Energy Levels Affect Rumen Bacterial Populations that Influence the Intramuscular Fat Fatty Acids of Fattening Yaks (Bos grunniens)

Animals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1474
Author(s):  
Rui Hu ◽  
Huawei Zou ◽  
Hongze Wang ◽  
Zhisheng Wang ◽  
Xueying Wang ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Energy Levels ◽  
Fatty Acid Content ◽  
Intramuscular Fat ◽  
Pcr Analysis ◽  
Rumen Bacteria ◽  
Dietary Energy ◽  
Bacterial Populations ◽  
Rdna Sequencing

The yak rumen microflora has more efficient fiber-degrading and energy-harvesting abilities than that of low-altitude cattle; however, few studies have investigated the effects of dietary energy levels on the rumen bacterial populations and the relationship between rumen bacteria and the intramuscular fatty acid profile of fattening yaks. In this study, thirty yaks were randomly assigned to three groups. Each group received one of the three isonitrogenous diets with low (3.72 MJ/kg), medium (4.52 MJ/kg), and high (5.32 MJ/kg) levels of net energy for maintenance and fattening. After 120 days of feeding, results showed that increasing dietary energy significantly increased ruminal propionate fermentation and reduced ammonia concentration. The 16S rDNA sequencing results showed that increasing dietary energy significantly increased the ratio of Firmicutes to Bacteroidetes and stimulated the relative abundance of Succiniclasticum, Saccharofermentans, Ruminococcus, and Blautia populations. The quantitative real-time PCR analysis showed that high dietary energy increased the abundances of Streptococcus bovis, Prevotella ruminicola, and Ruminobacter amylophilus at the species level. Association analysis showed that ruminal acetate was positively related to some intramuscular saturated fatty acid (SFA) contents, and Prevotella was significantly positively related to intramuscular total polyunsaturated fatty acid content and negatively related to intramuscular total SFA content. This study showed that high dietary energy mainly increased ruminal amylolytic and propionate-producing bacteria populations, which gave insights into how the effects of dietary energy on rumen bacteria are related to intramuscular fat fatty acids of fattening yaks.

scholarly journals First Report of Bacterial Blight of Sugar Beet Caused by Pseudomonas syringae pv. aptata in Georgia, USA

Plant Disease ◽  
2014 ◽  
Vol 98 (10) ◽  
pp. 1423-1423 ◽  
Author(s):  
B. Dutta ◽  
T. Ingram ◽  
R. D. Gitaitis ◽  
D. B. Langston ◽  
T. Brenneman ◽  
...  
Keyword(s):  
Sugar Beet ◽  
Pseudomonas Syringae ◽  
Type Strain ◽  
Bacterial Blight ◽  
23S Rrna ◽  
Pcr Analysis ◽  
First Report ◽  
Experimental Line ◽  
Physiological Tests ◽  
Rrna Sequences

Sugar beet (Beta vulgaris L.) is not currently a commercial crop in Georgia, but experimental plantings as a winter rotational crop are promising in terms of yield and industrial sugar production (T. Brenneman, personal communication). A disease outbreak of suspected bacterial origin occurred in sugar beet plots (experimental lines Beta Seed energy beet ‘BTS ENC115,’ ‘BTS EGC184,’ ‘BTS EGC195,’ and ‘BTS 1EN6702’) in Tift Co., GA, in December 2012, at ~35% incidence. Foliar symptoms included circular to irregular spots, each with a tan center and dark margin. Ten leaves/experimental line with leaf spot symptoms were collected, and bacterial isolations made on King's B agar medium. After 48 h of incubation, cream-colored, fluorescent yellow, round colonies with smooth margins were isolated. The isolates were each gram negative, oxidase negative, non-pectolytic on potato, arginine dihydrolase negative, produced levan, and gave a hypersensitivity response (HR) on tobacco. These characteristics indicated that the isolates belonged to Pseudomonas syringae van Hall LOPAT group Ia (3). The 16S-23S rRNA (internal transcribed regions) (1) from four foliar isolates (SB-1, SB-2, SB-3, and SB-4), one/experimental line, was amplified, and the resultant PCR products were sequenced and BLAST searched in GenBank. The 16S-23S rRNA sequences matched those of P. syringae pv. syingae (Pss) (KF023189) and P. syringae pv. aptata (Psa) (AY342167.1) with 96 to 98% and 97 to 99% sequence identity, respectively. Also, the percent similarity of the 16S-23S rRNA sequences among the four isolates was >99% (KJ922021 to 24 for SB-1 to SB-4, respectively). The four test isolates also had ≤89 and ≤99% similarity with Pss and Psa, respectively, when tested with BIOLOG (Hayward, CA). In addition, four sugarbeet isolates along with a type strain of Psa (NCPPB 3539) were amplified using a PCR primer pair that detected the presence of the avrPphE gene, an avirulence gene present in Psa but absent in Pss (2). The type strain of Pss (NCPPB 1770) was not amplified using this primer pair. BOX-PCR analysis gave identical banding patterns for the four isolates as that of a type strain of Psa. In two independent experiments, 3-week-old seedlings of the sugar beet cv. Beta EGR099 (n = 10 seedlings/isolate/experiment) were spray-inoculated with a sterilized water suspension of 1 × 108 CFU/ml of each of the isolates. All of the inoculated seedlings developed symptoms (water-soaked lesions that developed into necrotic spots) 10 days after inoculation (DAI) in greenhouse conditions (~30°C and ~80% RH). All of the seedlings inoculated with the type strain of Psa also produced typical bacterial blight symptoms at 10 DAI. In contrast, five control seedlings inoculated with sterilized water remained asymptomatic, and target bacterial colonies were not re-isolated from the leaves of these plants. Bacterial colonies were re-isolated from symptomatic seedlings, and showed similar characteristics based on physiological tests, BIOLOG profile, BOX-PCR analysis, and positive amplification with the avrPphE PCR assay, which indicated that these strains were Psa. To our knowledge, this is the first report of Psa in sugarbeet in Georgia. The fact that a Psa strain was also isolated from a sugar beet seed lot (data not shown) suggested that the pathogen may have been introduced on contaminated seeds. Knowledge of the presence of Psa in the agro-ecosystem of Georgia may encourage scientists to implement integrated management practices for this pathogen. References: (1) C. Guasp et al. Int. J. Syst. Evol. Microbiol. 50:1629, 2000. (2) Y. Inoue and Y. Takikawa. Page 687 in: Presentations 6th Int. Conf. Pseudomonas syringae Pathovars and Related Pathogens, 2003. (3) R. A. Lelliot et al. J. Appl. Bacteriol. 29:470, 1966.

Chemical Constituents in Some Promising Genotypes of Indian Mustard [Brassica juncea (L.) Czern and Coss.]

2017 ◽  
Vol 4 (04) ◽  
Author(s):  
SUNITA SINGH ◽  
R. P. SINGH ◽  
H. K. SINGH ◽  
N. A. KHAN ◽  
M. K. MAURYA
Keyword(s):  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Erucic Acid ◽  
Brassica Juncea ◽  
Acid Composition ◽  
Chemical Constituents ◽  
Indian Mustard ◽  
Acid Value ◽  
Fatty Acid Analysis ◽  
Crude Fibre

Among the oilseed Brassica crops, Indian mustard [Brassica juncea (L.) Czern and Coss.] is an important source of oil from a nutritional point of view. The nutritional value of oil and cake quality is governed mainly by the composition of its fatty acids, iodine value, saponification, acid value, glucosinolates, crude fibre, protein and limiting amino acids, etc. Seventeen varieties/strains of Indian mustard were taken for saturated and unsaturated fatty acid analysis. The eicosenoic was absent in genotype (NUDBYJ-10) and erucic acid (NUDBYJ-10, LES-46 and Pusa mustard- 21). The fatty acid composition found a variable in different genotypes. Saturated fatty acid, Palmitic + Stearic ranged between 2.3 to 6.5%, Oleic 10.6 to 40.7%, Linoleic 16.1 to 37.7%, Linolenic 13.3 to 26.7%, Eicosenoic 0.00 to 10.30% and Erucic acid 0.00 to 47.50%, respectively. Alternaria blight severity also varied in different genotypes and ranged between 18.75 to 56.25%, maximum being in genotype Kranti and minimum in LES-47. No significant correlation was observed between the fatty acid composition and disease severity. The oil content range from 38.1 to 42.60% and protein content was found highest in variety RGN-73. The amino acid viz. methionine and tryptophan range between 0.41 to 1.81 g/16gN and 0.41 to 1.81 g /16g N, respectively.

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