Epidemiology studies of Pseudomonas syringae pathovars associated with bacterial canker on the sweet cherry in Serbia

This study was conducted to examine the epidemiological characteristics of two Pseudomonas syringae pvs. – syringae (Pss) and morsprunorum race 1 (Psm) on the sweet cherry in both field and laboratory conditions. Cycled inoculations of one-year-old branches indicated that the sweet cherry became sensitive to Psm race 1 earlier in the season (October) compared to Pss (November). The most severe infections occurred in the dormancy period (November), while the necroses formed in January and March were less in their length. Inoculations of the two-/three-year-old branches performed in November resulted in necrosis, with those induced by Pss being more aggressive. The January inoculations, however, resulted in less formed necroses in length. Laboratory tests performed on excised sweet cherry branches confirmed the results yielded by the field experiments, indicating that the dormancy period poses the greatest risk for the P. syringae pvs. infection. The isolation of Pss and Psm bacteria from naturally infected sweet cherry samples (cankers) during the summer indicated that the bacteria that persists in cankers in low numbers became active during autumn. Significant Pss and Psm race 1 epiphytic bacterial populations were noted during the spring, but decreased in the summer and increased again in the autumn, indicating the presence of inoculum reservoirs. The greater understanding of the control strategies aimed at the epidemiological factors should, thus, facilitate better disease outbreak management.

Download Full-text

Characterization of Pseudomonas syringae pathovars from different sweet cherry cultivars by RAPD analysis

Genetika ◽

10.2298/gensr1601285i ◽

2016 ◽

Vol 48 (1) ◽

pp. 285-295 ◽

Cited By ~ 4

Author(s):

Renata Ilicic ◽

Jelica Balaz ◽

Vera Stojsin ◽

Dragana Josic

Keyword(s):

Pseudomonas Syringae ◽

Reference Strain ◽

Sweet Cherry ◽

Rapd Analysis ◽

Plant Organs ◽

Race 1 ◽

Pseudomonas Syringae Pathovars ◽

Sweet Cherry Cultivars

Pseudomonas syringae pvs., isolated from sweet cherry grown on different localities in Serbia, were genetically characterized using RAPD analysis. Four out of eleven tested primers (SPH1, DJP 17, DJ 15, and DJ 16) were selected on the basis of the differences between isolates within two pathovars - syringae and morsprunorum race 1. Cumulative RAPD analysis indicated heterogeneity within the population of both groups of tested isolates, revealing four different patterns in each group. RAPD analysis showed up to 24% differences among pv. syringae isolates, as well as 41% in comparison with the reference strain KFB0103 (pv. syringae), while differences of 15% among isolates pv. morsprunorum 1 race and 36% compared to the reference strain CFBP2119 (pv. morsprunorum 1) were observed. Isolates from locality Selenca exhibited three different genotypic patterns of pv. morsprunorum race 1 and one pattern of pv. syringae. Isolates of pv. morsprunorum collected in the same year from two plant organs (branches and leaves) of the cv. Vanda yielded two different patterns. The pv. morsprunorum on cv. Kordia and pv. syringae on cv. Regina were detected at Mikicevo locality. The same patterns were observed for isolates of pv. syringae from Kanjiza and Selenca, as well as from Gornji Tavankut in two years of isolation. Differences were noted between isolates from the same pathovar originating from Ljutovo and Mikicevo, as well as with respect to all other isolates of same pathovar.

Download Full-text

Identification of QTLs controlling resistance to Pseudomonas syringae pv. tomato race 1 strains from the wild tomato, Solanum habrochaites LA1777

Theoretical and Applied Genetics ◽

10.1007/s00122-015-2463-7 ◽

2015 ◽

Vol 128 (4) ◽

pp. 681-692 ◽

Cited By ~ 22

Author(s):

Shree Prasad Thapa ◽

Eugene M. Miyao ◽

R. Michael Davis ◽

Gitta Coaker

Keyword(s):

Pseudomonas Syringae ◽

Wild Tomato ◽

Solanum Habrochaites ◽

Race 1

Download Full-text

The Contribution of Syringopeptin and Syringomycin to Virulence of Pseudomonas syringae pv. syringae strain B301D on the Basis of sypA and syrB1 Biosynthesis Mutant Analysis

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi.2001.14.3.336 ◽

2001 ◽

Vol 14 (3) ◽

pp. 336-348 ◽

Cited By ~ 83

Author(s):

Brenda K. Scholz-Schroeder ◽

Michael L. Hutchison ◽

Ingeborg Grgurina ◽

Dennis C. Gross

Keyword(s):

Pseudomonas Syringae ◽

High Performance ◽

Sweet Cherry ◽

Peptide Structure ◽

Acid Activation ◽

Virulence Determinants ◽

Amino Acid Activation ◽

Peptide Synthetases ◽

Peptide Synthetase ◽

Peptide Biosynthesis

Sequencing of an approximately 3.9-kb fragment downstream of the syrD gene of Pseudomonas syringae pv. syringae strain B301D revealed that this region, designated sypA, codes for a peptide synthetase, a multifunctional enzyme involved in the thiotemplate mechanism of peptide biosynthesis. The translated protein sequence encompasses a complete amino acid activation module containing the conserved domains characteristic of peptide synthetases. Analysis of the substrate specificity region of this module indicates that it incorporates 2,3-dehydroaminobutyric acid into the syringopeptin peptide structure. Bioassay and high performance liquid chromatography data confirmed that disruption of the sypA gene in strain B301D resulted in the loss of syringopeptin production. The contribution of syringopeptin and syringomycin to the virulence of P. syringae pv. syringae strain B301D was examined in immature sweet cherry with sypA and syrB1 synthetase mutants defective in the production of the two toxins, respectively. Syringopeptin (sypA) and syringomycin (syrB1) mutants were reduced in virulence 59 and 26%, respectively, compared with the parental strain in cherry, whereas the syringopeptin-syringomycin double mutant was reduced 76% in virulence. These data demonstrate that syringopeptin and syringomycin are major virulence determinants of P. syringae pv. syringae.

Download Full-text

Echinococcus granulosus genotypes in Iran: a systematic review

Journal of Helminthology ◽

10.1017/s0022149x18000275 ◽

2018 ◽

Vol 93 (2) ◽

pp. 131-138 ◽

Cited By ~ 25

Author(s):

S. Khademvatan ◽

H. Majidiani ◽

M. Foroutan ◽

K. Hazrati Tappeh ◽

S. Aryamand ◽

...

Keyword(s):

Systematic Review ◽

Echinococcus Granulosus ◽

Web Of Science ◽

Control Strategies ◽

Scientific Information ◽

Isfahan Province ◽

West Azerbaijan ◽

Epidemiological Characteristics ◽

Information Database ◽

Echinococcus Granulosus Sensu Lato

AbstractCystic echinococcosis (CE) caused by Echinococcus granulosus sensu lato (s.l.) is a significant zoonosis, especially in developing countries of the Middle East, with many studies focusing on CE genotypes in Iran. We performed a systematic review to determine the exact status of E. granulosus genotypes in the country. We explored English (Pubmed, Scopus, ISI Web of Science and Science Direct) and Persian (Magiran, Iran Medex and Scientific Information Database) databases along with Google Scholar. Our review included 73 studies published prior to the end of 2015. In total, 2952 animal (intermediate and definitive) hosts were examined, and the prevalent genotypes comprised G1 (92.75%) and G6 (4.53%) in sheep, cattle, camels, goats and buffaloes; G3 (2.43%) in five herbivore hosts and dogs; G7 (0.2%) in sheep and goats; and G2 (0.06%) in dogs. G1 was mostly dominant in West Azerbaijan, whereas G3 and G6 were identified most frequently in the provinces of Isfahan and Fars, respectively. Regarding human CE infection, 340 cases were reported from Iran, with the identified genotypes G1 (n = 320), G6 (n = 13) and G3 (n = 7). Most CE-infected humans originated from Isfahan province (168 cases), whereas the lowest number of infected persons was noted in Kerman province (two cases). The information obtained from this systematic review is central to better understanding the biological and epidemiological characteristics of E. granulosus s.l. genotypes in Iran, leading to more comprehensive control strategies.

Download Full-text

Integrated Wild Oat (Avena fatua) Management Affects Spring Barley (Hordeum vulgare) Yield and Economics

Weed Technology ◽

10.1017/s0890037x00034424 ◽

1992 ◽

Vol 6 (1) ◽

pp. 129-135 ◽

Cited By ~ 24

Author(s):

David L. Barton ◽

Donald C. Thill ◽

Bahman Shafii

Keyword(s):

Grain Yield ◽

Field Experiments ◽

Control Strategies ◽

Integrated Control ◽

Spring Barley ◽

Barley Grain ◽

Row Spacing ◽

Wild Oat ◽

Seeding Rate ◽

Net Return

The effect of barley seeding rate and row spacing, and triallate, diclofop, and difenzoquat herbicide rate on barley grain yield and quality, and wild oat control were evaluated in field experiments near Bonners Ferry, Idaho, in 1989 and 1990. The purpose of the study was to develop integrated control strategies for wild oat in spring barley. Barley row spacing (9 and 18 cm) did not affect barley grain yield. Barley grain yield was greatest when barley was seeded at 134 or 201 kg ha–1compared to 67 kg ha–1. Wild oat control increased as wild oat herbicide rate increased and barley grain yield was greatest when wild oat herbicides were applied. However, barley grain yield was similar when wild oat biomass was reduced by either 65 or 85% by applications of half and full herbicide rates, respectively. Net return was greatest when the half rate of herbicide was applied to 100 wild oat plants per m2and was greatest when half or full herbicide rates were applied to 290 wild oat plants per m2. Net return increased when the seeding rate was increased to 134 or 201 kg ha–1when no herbicide was applied and when 290 wild oat plants per m2were present.

Download Full-text

Effects of Environmental Factors on Seed Germination and Emergence of Velvetleaf (Abutilon theophrasti)

Planta Daninha ◽

10.1590/s0100-83582018360100122 ◽

2018 ◽

Vol 36 (0) ◽

Cited By ~ 2

Author(s):

RC. XIONG ◽

Y. MA ◽

HW. WU ◽

WL. JIANG ◽

XY. MA

Keyword(s):

Seed Germination ◽

Environmental Factors ◽

Field Experiments ◽

Cropping Systems ◽

Control Strategies ◽

Seedling Emergence ◽

Central China ◽

Burial Depth ◽

Temperature Regimes ◽

Alternating Temperature

ABSTRACT: Velvetleaf, an annual broadleaf weed, is a common and troublesome weed of cropping systems worldwide. Laboratory and field experiments were conducted to determine the effects of environmental factors on germination and emergence of velvetleaf. Seeds germinated over a range of constant temperatures from 10 to 40 oC regardless of light conditions, but no germination occurred at temperature below 5 oC and beyond 50 oC. Seeds germinated at alternating temperature regimes of 15/5 to 40/30 oC, with maximum germination (>90%) at alternating temperatures of 40/30 oC. Germination was sensitive to water stress, and only 0.4% of the seeds germinated at the osmotic potential of -0.4 MPa. There was no germination at ? 0.6 MPa. Moreover, germination was reduced by saline and alkaline stresses and no germination occurred at ³ 150 mM NaCl or ³ 200 mM NaHCO3 concentrations. However, pH values from 5 to 9 had no effect on seed germination. Seedling emergence was significantly affected by burial depth and maximum emergence (78.1-85.6%) occurred at the 1-4 cm depth. The results of this study have contributed to our understanding of the germination and emergence of velvetleaf and should enhance our ability to improve control strategies in cropping systems in central China.

Download Full-text

Occurrence of Pseudomonas syringae pv. Tomato race 1 in Italy on Pto Gene-Bearing Tomato Plants

Journal of Phytopathology ◽

10.1111/j.1439-0434.1996.tb00320.x ◽

1996 ◽

Vol 144 (9-10) ◽

pp. 437-440 ◽

Cited By ~ 14

Author(s):

R. Buonaurio ◽

V. M. Stravato ◽

C. Cappelli

Keyword(s):

Pseudomonas Syringae ◽

Tomato Plants ◽

Race 1

Download Full-text

Comparative prevalences of Ascaris lumbricoides, Trichuris trichiura and hookworm infections and the prospects for combined control

Parasitology ◽

10.1017/s0031182000073807 ◽

1992 ◽

Vol 105 (1) ◽

pp. 151-157 ◽

Cited By ~ 38

Author(s):

M. Booth ◽

D. A. P. Bundy

Keyword(s):

Ascaris Lumbricoides ◽

Control Strategies ◽

Trichuris Trichiura ◽

Hookworm Infection ◽

Simultaneous Control ◽

Precise Locality ◽

Combined Control ◽

Multiple Species ◽

Epidemiological Characteristics ◽

Hookworm Infections

Programmes to control Ascaris lumbricoides, Trichuris trichiura and hookworm infections have often been targeted at each infection separately, but the advent of benign and broad-spectrum anthelmintics suggests that combined control ma be feasible. The extent to which the infections co-occur in communities will determine the need for, and potential benefits of, such a combined approach. This paper examines the comparative distribution of the three geohelminths in different geographical areas and shows that A. lumbricoides and T. trichiura have closely related distributions, while hookworm infection is largely independent of the other two. These results indicate that many communities are at risk of disease from infection by more than one species of helminth. The similar distributions and epidemiological characteristics of A. lumbricoides and T. trichiura suggest that simultaneous control of these two parasites by the same strategy would be feasible and highly beneficial to communities. Multiple species control strategies which aim to control hookworm infection may require a more complicated protocol with more precise locality targeting.

Download Full-text

Field Control of Bacterial Spot and Bacterial Speck of Tomato Using a Plant Activator

Plant Disease ◽

10.1094/pdis.2001.85.5.481 ◽

2001 ◽

Vol 85 (5) ◽

pp. 481-488 ◽

Cited By ~ 179

Author(s):

F. J. Louws ◽

M. Wilson ◽

H. L. Campbell ◽

D. A. Cuppels ◽

J. B. Jones ◽

...

Keyword(s):

Pseudomonas Syringae ◽

Systemic Acquired Resistance ◽

Field Experiments ◽

Production Systems ◽

Acquired Resistance ◽

Dry Weight ◽

Bacterial Spot ◽

Population Densities ◽

Bacterial Speck ◽

Plant Activator

Acibenzolar-S-methyl (CGA 245704 or Actigard 50WG) is a plant activator that induces systemic acquired resistance (SAR) in many different crops to a number of pathogens. Acibenzolar-S-methyl was evaluated for management of bacterial spot (Xanthomonas axonopodis pv. vesicatoria) and bacterial speck (Pseudomonas syringae pv. tomato) of tomato in 15 and 7 field experiments, respectively. Experiments were conducted over a 4-year period in Florida, Alabama, North Carolina, Ohio, and Ontario using local production systems. Applied at 35 g a.i. ha-1, acibenzolar-S-methyl reduced foliar disease severity in 14 of the 15 bacterial spot and all 7 bacterial speck experiments. Disease control was similar or superior to that obtained using a standard copper bactericide program. Acibenzolar-S-methyl also reduced bacterial fruit spot and speck incidence. Tomato yield was not affected by using the plant activator in the field when complemented with fungicides to manage foliar fungal diseases, but tomato transplant dry weight was negatively impacted. X. axonopodis pv. vesicatoria population densities on greenhouse-grown tomato transplants were reduced by acibenzolar-S-methyl treatment. Bacterial speck and spot population densities on leaves of field-grown plants were not dramatically affected. Acibenzolar-S-methyl can be integrated as a viable alternative to copper-based bactericides for field management of bacterial spot and speck, particularly where copper-resistant populations predominate.

Download Full-text