scholarly journals Presence of Pseudomonas syringae pv actinidiae the causal agent of bacterial canker of kiwifruit on symptomatic and asymptomatic tissues of kiwifruit

2011 ◽  
Vol 64 ◽  
pp. 241-245 ◽  
Author(s):  
J.L. Vanneste ◽  
J. Yu ◽  
D.A. Cornish ◽  
S. Max ◽  
G. Clark
Keyword(s):  
Pseudomonas Syringae ◽  
Vascular System ◽  
Causal Agent ◽  
Bacterial Canker ◽  
Effective Strategy ◽  
Bacterial Isolation ◽  
Chain Reaction ◽  
Leaf Spots ◽  
Polymerase Chain ◽  
Different Parts

Pseudomonas syringae pv actinidiae (Psa) the causal agent of bacterial canker of kiwifruit has recently been found in New Zealand This pathogen has been the object of few studies and little is known about its epidemiology Yet the development of an effective strategy of control requires an understanding of the life cycle of the pathogen in particular determining the location of the bacteria in tissues In this study the presence of Psa on flowers symptomatic and asymptomatic leaves and different parts of canes showing symptoms was determined by polymerase chain reaction (PCR) or by direct bacterial isolation Psa was found associated with angular necrotic leaf spots with white exudate and in canes In canes Psa seemed to be either in the parenchyma leading to production of exudate or in the vascular system leading to wilting Psa was also found on asymptomatic tissues where it was probably surviving as an epiphyte

scholarly journals Detection of Pseudomonas syringae pv actinidiae in kiwifruit pollen samples

2011 ◽  
Vol 64 ◽  
pp. 246-251 ◽  
Author(s):  
J.L. Vanneste ◽  
D. Giovanardi ◽  
J. Yu ◽  
D.A. Cornish ◽  
C. Kay ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
New Zealand ◽  
Pseudomonas Syringae ◽  
Bacterial Canker ◽  
Bacterial Isolation ◽  
Chain Reaction ◽  
Male And Female ◽  
First Report ◽  
Vacuum Device ◽  
Polymerase Chain

Presence of Pseudomonas syringae pv actinidiae (Psa) the causal agent of bacterial canker of kiwifruit in pollen samples collected from infected and non infected orchards in Italy and in New Zealand was determined by polymerase chain reaction (PCR) and by direct bacterial isolation Psa was isolated only from pollen samples collected in Italy including pollen collected from two uninfected orchards which the following year showed signs of infection Psa was also detected in pollen collected from male and female vines in an Italian infected orchard Pollen samples from Italy but not from New Zealand were collected with a vacuum device Psa could not be isolated from any of the 25 New Zealand pollen samples analysed This is the first report of Psa being associated with pollen There is currently no evidence that artificial pollination leads to increased infection or that pollen has been responsible for the introduction of Psa in a previously Psafree area

scholarly journals Identification, Virulence, and Distribution of Two Biovars of Pseudomonas syringae pv. actinidiae in New Zealand

Plant Disease ◽  
2013 ◽  
Vol 97 (6) ◽  
pp. 708-719 ◽  
Author(s):  
J. L. Vanneste ◽  
J. Yu ◽  
D. A. Cornish ◽  
D. J. Tanner ◽  
R. Windner ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
New Zealand ◽  
Disease Progression ◽  
Pseudomonas Syringae ◽  
Electrophoretic Pattern ◽  
Bacterial Canker ◽  
Chain Reaction ◽  
Leaf Spots ◽  
Polymerase Chain ◽  
First Time

Pseudomonas syringae pv. actinidiae, the causal agent of bacterial canker of kiwifruit, was detected for the first time in New Zealand in November 2010. Only in Bay of Plenty, one of the four regions where this pathogen had been detected, did symptoms evolve beyond leaf spots, resulting in cane die-back, wilting of canes, and canker, sometimes leading to death of the vine. Molecular analysis (cts haplotype and BOX-polymerase chain reaction [PCR] electrophoretic pattern) of strains isolated from different regions of New Zealand revealed that two biovars could be distinguished. They have been called biovar 3 and biovar 4 to differentiate them from strains from Japan (biovar 1) or Korea (biovar 2), which have a different cts haplotype or a different BOX-PCR pattern. Biovars 3 and 4 displayed different degrees of virulence, as measured by their ability to cause leaf spots on young, potted kiwifruit plants. Biovar 3, which has also been present in Italy since 2008 and in France, was found in the Bay of Plenty, where cane diebacks were observed. In contrast, no symptoms other than leaf spots have been observed in orchards where strains of biovar 4 have been isolated. We report the distribution and the disease progression of biovars 3 and 4 in New Zealand.

scholarly journals In vitro inhibition of Pseudomonas syringae pv actinidiae by wound protectants

2015 ◽  
Vol 68 ◽  
pp. 332-339
Author(s):  
D.A. Cornish ◽  
J. Yu ◽  
J.M. Oldham ◽  
J. Benge ◽  
W. Max ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Antibacterial Activity ◽  
Pseudomonas Syringae ◽  
Disease Incidence ◽  
Bacterial Canker ◽  
Streptomycin Sulphate ◽  
Chain Reaction ◽  
Commercial Formulation ◽  
Polymerase Chain

Preventing Pseudomonas syringae pv actinidiae (Psa) the causal agent of bacterial canker of kiwifruit from entering pruning wounds would reduce disease incidence and facilitate canopy management Antibacterial activity against Psa has been determined in the laboratory for active ingredients commercially available in New Zealand Only tebuconazole tebuconazole with octhilinone and a formulation of cyproconazole and iodocarb killed Psa on agar plates or in liquid medium However only tebuconazole with octhilinone killed Psa within 5 min Psa was detected by polymerase chain reaction following plating on instruments used for applying wound protectants in an infected orchard This suggests that under some conditions the pathogen could be transferred from vine to vine when applying some wound protectants Addition of streptomycin sulphate to tebuconazole or a formulation of cyproconazole and iodocarb did not result in a rapid and complete kill of Psa similar to that with a commercial formulation of streptomycin applied alone

scholarly journals Rapid Diagnosis of Pseudomonas syringae pv. papulans, the Causal Agent of Blister Spot of Apple, by Polymerase Chain Reaction Using Specifically Designed hrpL Gene Primers

2002 ◽  
Vol 92 (10) ◽  
pp. 1077-1083 ◽  
Author(s):  
Mohamed Kerkoud ◽  
Charles Manceau ◽  
Jean Pierre Paulin
Keyword(s):  
Polymerase Chain Reaction ◽  
Pseudomonas Syringae ◽  
Polymerase Chain Reaction Amplification ◽  
Restriction Enzymes ◽  
Causal Agent ◽  
Chain Reaction ◽  
Diseased Fruit ◽  
Polymerase Chain ◽  
Primer Sets ◽  
Consensus Primers

The identification and detection of Pseudomonas syringae pv. papulans, the causal agent of blister spot of apple, on apple leaves and fruit was achieved by polymerase chain reaction amplification of a specific DNA fragment of the hrpL sequence. The consensus primers hrpL1 and hrpL2 were designed based on the alignment of pseudomonad hrpL gene sequences available in nucleic acid data banks. This primer set produced a 631-bp amplicon from 37 of the 57 pseudomonads strains tested. These strains belonged to genomospecies 1 and 2, as described by Gardan et al. (8). The amplicon obtained from 30 of these strains was digested with eight restriction enzymes. Three different restriction patterns were produced from strains belonging to genomospecies 1, resulting in A1 and A2 patterns, while strains belonging to genomospecies 2 were characterized by a B pattern. Patterns A1 and A2 differed at only two sites, a Bsp 143I site located at nucleotide 360 and a MseI site located at nucleotides 22–24. Group A2 consisted solely of P. syringae pv. papulans strains. The hrpL gene in P. syringae pv. papulans strain CFBP3323 was sequenced. Two primer sets, Pap1/Pap2 and Pap1/Pap3, were designed and tested for specificity to P. syringae pv. papulans. These primers amplified expected fragments of 242 and 303 bp, respectively. Pap1/Pap2 amplified a fragment only with P. syringae pv. papulans DNA, while Pap1/Pap3 amplified all tested strains belonging to genomospecies 1. A diagnostic procedure using the Pap1/Pap2 primer set was successful for the detection of P. syringae pv. papulans in diseased fruit and artificially inoculated leaves.

Effect of a protectant copper application on Psa infection of kiwifruit trap plants

2017 ◽  
Vol 70 ◽  
pp. 310-314
Author(s):  
J.L. Tyson ◽  
S.J. Dobson ◽  
M.A. Manning
Keyword(s):  
New Zealand ◽  
Disease Control ◽  
Pseudomonas Syringae ◽  
Low Risk ◽  
Bacterial Canker ◽  
Complete Protection ◽  
Leaf Spots ◽  
Copper Compounds ◽  
Trap Plants

Pseudomonas syringae pv. actinidiae (Psa) causes bacterial canker of kiwifruit, which is an ongoing threat to New Zealand kiwifruit production. Disease control depends on orchard practices such as removal of visibly diseased material, pruning during low-risk periods, and the application of foliar bactericides. Although the use of copper compounds on Actinidia species (kiwifruit) can cause phytotoxicity, copper-based formulations remain a key component of Psa control in New Zealand. The effect of single copper applications on Psa infection of ‘Hort16A’ trap plants was studied over the Spring of 2014 (Sept—Nov). Psa leaf spots were observed at the beginning of October, appearing first on the untreated plants. Although the copper sprays did not achieve complete protection, particularly as the inoculum built up during November, the copper-sprayed plants always had less disease than the untreated plants.

scholarly journals Essential Oils with Inhibitory Capacities on Pseudomonas syringae pv. actinidiae, the Causal Agent of Kiwifruit Bacterial Canker

2017 ◽  
Vol 12 (1) ◽  
pp. 16-26 ◽  
Author(s):  
Pucci Nicoletta ◽  
Orzali Laura ◽  
Modesti Vanessa ◽  
Lumia Valentina ◽  
Brunetti Angela ◽  
...  
Keyword(s):  
Essential Oils ◽  
Pseudomonas Syringae ◽  
Causal Agent ◽  
Bacterial Canker

A mutation in an exbD gene reduces tagetitoxin production by Pseudomonas syringae pv. tagetis

2006 ◽  
Vol 52 (11) ◽  
pp. 1027-1035 ◽  
Author(s):  
Hyesuk Kong ◽  
Cheryl D Patterson ◽  
Robin E Mitchell ◽  
Jeffrey S Buyer ◽  
M Catherine Aime ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Wild Type Strain ◽  
Efflux Pump ◽  
Wild Type ◽  
Chain Reaction ◽  
Sequence Identity ◽  
Mutant Strains ◽  
Tonb System ◽  
Polymerase Chain ◽  
High Degree

A mutant of Pseudomonas syringae pv. tagetis EB037 with limited ability to produce tagetitoxin was isolated after transposon mutagenesis and the mutation was characterized. The mutation occurred in a gene with a high degree of sequence identity to exbD. exbD is contiguous with tonB and exbB upstream and with a gene for a TonB-dependent receptor downstream. Using reverse transcription – polymerase chain reaction with RNA from the wild-type and exbD mutant strains, we demonstrated that the mutation in exbD did not have a polar affect on the expression of downstream genes. The exbD mutant was able to grow well in conditions where iron is not freely available. Siderophore production by the exbD mutant was similar to that of the wild-type strain. We conclude that the mutation in exbD disrupts tagetitoxin production without compromising iron metabolism. The results indicate that tagetitoxin export by P. syringae pv. tagetis involves an efflux pump that requires a functional TonB system that is not essential for normal iron metabolism.Key words: Pseudomonas syringae pv. tagetis, Pseudomonas putida, tagetitoxin, exbD, exbB, tonB, TonB system, Helianthus annuus L.

scholarly journals Bovine tuberculosis: Diagnosis by PCR technique in bovine milk samples

2013 ◽  
Vol 37 (2) ◽  
pp. 156-160
Author(s):  
Mohammed J. Alwan
Keyword(s):  
Bovine Milk ◽  
Culture Method ◽  
Bacterial Isolation ◽  
Chain Reaction ◽  
Pcr Assay ◽  
Culture Methods ◽  
Milk Samples ◽  
Tuberculosis Diagnosis ◽  
Pcr Method ◽  
Polymerase Chain

     The aim of this study was to determine the percentage of borne tuberculin infection in milk sample by using PCR.  (102) milk samples were collected from  cows , AL-Dejella (39) samples,  AL-Suara (20) samples cow station, AL-Fthalia (20) samples,  AL-Azezia (11) samples and AL-Twarege (12) samples (Iraq) during the period  July 10th   2010 to  Nov.30th   2010. The samples were examined by direct smear stained by Ziehle-Neelson stain, culture methods and confirmed the isolates by Polymerase Chain Reaction (PCR) assay. The results showed that  5, 102 (4.9%) milk samples were M. bovis positive that were detected by direct milk smear method and 10 out 102(9.8%) M.bovis +ve were detected by culture method and PCR assay. The results also showed that high percentage of bacterial isolates from milk samples AL-Dejella city show (12.8%) by culturing and PCR method followed by AL-Suara (10%), AL-Fthelia (10%), Al-Twarege (8.3%) but no bacterial isolation was recorded in AL-Azezia milk samples. This study concluded that M.bovis infection was spreading in dairy cow within the mentioned areas and PCR was more sensitive, rapid, and accurate technique for M.bovis infection diagnosis.

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