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Bruce C. Kirkpatrick - One of the best experts on this subject based on the ideXlab platform.
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Effect of calcium and nitrogen fertilization on bacterial canker susceptibility in Stone Fruits
Fruits, 2013Co-Authors: Tiesen Cao, Roger A. Duncan, Bruce C. Kirkpatrick, Kenneth A. Shackel, Theodore M. DejongAbstract:Introduction . Bacterial canker, caused by Pseudomonas syringae pv. syringae , is a destructive disease where Stone fruit trees are cultivated. The efficacy of nitrogen and calcium fertilization on bacterial canker susceptibility was evaluated in Stone Fruits. Materials and methods . Field experiments were conducted to study the efficacy of foliar applications of calcium nitrate, and ground fertilization with CAN-17 plus low-biuret urea foliar spray on bacterial susceptibility in ‘Riegel’ peach, ‘French’ prune and ‘Nonpareil’ almond growing in ring nematode-infested and nematicide-fumigated soils. Host susceptibility was evaluated by measuring the length of lesions developed following inoculation with P. syringae pv. syringae . Results and discussion . Foliar applications of Ca(NO3 )2 significantly increased leaf nitrogen and bark calcium concentrations in peach trees growing in both fumigated and nonfumigated areas. Peach trees growing in nonfumigated areas developed significantly longer lesions than trees growing in fumigated areas. However, Ca(NO3 )2 foliar applications had no effect in decreasing peach susceptibility to bacterial infection in both nonfumigated and fumigated areas. After inoculation, diseased prune trees developed significantly longer lesions than healthy trees. Leaf and bark calcium concentrations of diseased prune were significantly increased after Ca(NO3 )2 foliar sprays, but again the treatments did not significantly affect prune susceptibility to bacterial infection. However, nitrogen fertilization with CAN-17 and urea significantly increased the bark nitrogen concentration of almond trees, and these trees had significantly smaller lesions than those not receiving nitrogen fertilization. Foliar application of calcium (Nutri-Cal) did not affect almond susceptibility to bacterial canker. Collectively, these data support the previous hypothesis that increased susceptibility of Stone Fruits to P. syringae pv. syringae under nematode infestation conditions is mediated by both nitrogen effects and nitrogen-independent effects, and application of ammonium nitrogen may have some beneficial effects in reducing Stone fruit susceptibility to bacterial canker where ring nematode infestation prevails.
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Genetic characterization of Pseudomonas syringae pv. syringae strains from Stone Fruits in California.
Applied and environmental microbiology, 1998Co-Authors: E. L. Little, Richard M. Bostock, Bruce C. KirkpatrickAbstract:Strains of Pseudomonas syringae pv. syringae were isolated from healthy and diseased Stone fruit tissues sampled from 43 orchard sites in California in 1995 and 1996. These strains, together with P. syringae strains from other hosts and pathovars, were tested for pathogenicity and the presence of the syrB and syrC genes and were genetically characterized by using enterobacterial repetitive intergenic consensus (ERIC) primers and PCR. All 89 strains of P. syringae pv. syringae tested were moderately to highly pathogenic on Lovell peach seedlings regardless of the host of origin, while strains of other pathovars exhibited low or no pathogenicity. The 19 strains of P. syringae pv. syringae examined by restriction fragment length polymorphism analysis contained the syrB and syrC genes, whereas no hybridization occurred with 4 strains of other P. syringae pathovars. The P. syringae pv. syringae strains from Stone fruit, except for a strain from New Zealand, generated ERIC genomic fingerprints which shared four fragments of similar mobility. Of the P. syringae pv. syringae strains tested from other hosts, only strains from rose, kiwi, and pear generated genomic fingerprints that had the same four fragments as the Stone fruit strains. Analysis of the ERIC fingerprints from P. syringae pv. syringae strains showed that the strains isolated from Stone Fruits formed a distinct cluster separate from most of the strains isolated from other hosts. These results provide evidence of host specialization within the diverse pathovar P. syringae pv. syringae.
Jaime Cubero - One of the best experts on this subject based on the ideXlab platform.
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Xanthomonas arboricola pv. pruni, causal agent of bacterial spot of Stone Fruits and almond: its genomic and phenotypic characteristics in the X. arboricola species context.
Molecular plant pathology, 2018Co-Authors: Jerson Garita-cambronero, Ana Palacio-bielsa, Jaime CuberoAbstract:Background Xanthomonas arboricola pv. pruni (Xap) causes bacterial spot of Stone Fruits and almond, an important disease that may reduce the yield and vigour of the trees, as well as the marketability of affected Fruits. Xap lies within the Xanthomonas genus, which has been intensively studied because of its strain specialization and host range complexity. Here, we summarize the recent advances in our understanding of the complexities of Xap, including studies of the molecular features that result after comparative phenotypic and genomic analyses, in order to obtain a clearer overview of the bacterial behaviour and infection mechanism in the context of the X. arboricola species. Taxonomic status Bacteria; Phylum Proteobacteria; Class Gammaproteobacteria; Order Xanthomonadales; Family Xanthomonadaceae; Genus Xanthomonas; Species X. arboricola; Pathovar pruni. Host range and symptoms Xap infects most Prunus species, including apricot, peach, nectarine, plum and almond, and occasionally cherry. Symptoms are found on leaves, Fruits, twigs and branches or trunks. In severe infections, defoliation and fruit dropping may occur. Distribution Bacterial spot of Stone Fruits and almond is worldwide in distribution, with Xap being isolated in Africa, North and South America, Asia, Europe and Oceania. It is a common disease in geographical areas in which Stone Fruits and almonds are grown. Xap is listed as a quarantine organism in several areas of the world. Genome The genomes of six isolates from Xap have been publicly released. The genome consists of a single chromosome of around 5 000 000 bp with 65 mol% GC content and an extrachromosomal plasmid element of around 41 000 bp with 62 mol% GC content. Genomic comparative studies in X. arboricola have allowed the identification of putative virulence components associated with the infection process of bacterial spot of Stone Fruits and almond. Disease control Management of bacterial spot of Stone Fruits and almond is based on an integrated approach that comprises essential measures to avoid Xap introduction in a production zone, as well as the use of tolerant or resistant plant material and chemical treatments, mainly based on copper compounds. Management programmes also include the use of appropriate cultivation practices when the disease is already established. Finally, for the effective control of the disease, appropriate detection and characterization methods are needed for use in symptomatic or asymptomatic samples as a first approach for pathogen exclusion. USEFUL WEBSITES: https://gd.eppo.int/taxon/XANTPR; http://www.cost.eu/COST_Actions/ca/CA16107; http://www.xanthomonas.org.
Themis J. Michailides - One of the best experts on this subject based on the ideXlab platform.
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Development of qPCR systems to quantify shoot infections by canker-causing pathogens in Stone Fruits and nut crops.
Journal of applied microbiology, 2016Co-Authors: Yong Luo, Dan Felts, Ryan D. Puckett, D.p. Morgan, Themis J. MichailidesAbstract:Aims To develop real-time PCR assays for quantification of shoot infection levels of canker disease of Stone Fruits and nut crops caused by six fungal pathogen groups. Methods and Results This study focused on six major canker-causing fungal pathogen groups: Phomopsis spp., Botryosphaeria dothidea, Lasiodiplodia spp., Cytospora spp., Neofusicoccum spp., and Diplodia spp., occurring in Stone Fruits and nut crops in California. DNA primers were designed to specifically target each of the six pathogen groups after the specificity tests using canker-causing and non-canker-causing pathogens and by using DNA sequences of other species from GenBank using BLAST. The quantitative real-time PCR (qPCR) systems were developed and used to quantify the infection levels of inoculated dried plum shoots. Conclusions For Neofusicoccum spp. and Phomopsis spp., which were used in inoculation of walnut shoots, the values of the molecular severity ranged from 5.60 to 6.94 during the 16 days of latent infection period. The qPCR assays were more efficient, accurate and precise to quantify latent infections caused by canker-causing pathogens as compared to the traditional plating methods. Significance and Impact of the Study This study demonstrated the potential of using the developed qPCR systems for epidemiological studies on canker diseases of woody plants. This article is protected by copyright. All rights reserved.
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Species-Specific Detection of Monilinia fructicola from California Stone Fruits and Flowers
Phytopathology, 2001Co-Authors: Eric W. A. Boehm, Themis J. MichailidesAbstract:Boehm, E. W. A., Ma, Z., and Michailides, T. J. 2001. Species-specific detection of Monilinia fructicola from California Stone Fruits and flowers. Phytopathology 91:428-439. A set of molecular diagnostics was developed for Monilinia fructicola, causal agent of brown rot of Stone Fruits, capable of sensitive detection of the pathogen in planta. Species-specific repetitive sequences were identified from a partial library of 312 recombinant clones hybridized with total DNA, followed by subsequent screening for specificity. One hundred isolates, comprising 12 fungal species common to California Stone Fruits, were surveyed for specificity. Three clones hybridized to 60 geographically diverse M. fructicola isolates (California, Michigan, Georgia, Oregon, and Australia) to the exclusion of all other fungi surveyed, including the closely related M. laxa (n = 12). Two clones were identical and of extrachromosomal origin (pMF73 and pMF150), whereas the third (pMF210) migrated with uncut DNA. The sensitivity of all three was comparable and capable of detecting 50 pg of fungal DNA in dot blot hybridizations. Six species-specific primer pair sets were designed. They maintained the same specificity patterns observed in the initial hybridization surveys and were sensitive enough to detect 50 fg of fungal DNA template, approximately equivalent to 10 spores. The speciesspecific clones were capable of detecting the pathogen in planta, specifically from infected plum flowers and nectarine fruit tissue, using both hybridization- and polymerase chain reaction-based methodologies.
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effects of wounding inoculum density and biological control agents on postharvest brown rot of Stone Fruits
Plant Disease, 1998Co-Authors: Chuanxue Hong, Themis J. Michailides, B A HoltzAbstract:ABSTRACT The effects of wounding, inoculum density, and three isolates (New, Ta291, and 23-E-6) of Trichoderma spp. and one isolate (BI-54) of Rhodotorula sp. on postharvest brown rot of Stone Fruits were determined at 20°C and 95% relative humidity (RH). Brown rot was observed frequently on wounded nectarine, peach, and plum Fruits inoculated with two spores of Monilinia fructicola per wound, and occasionally on unwounded nectarine and peach Fruits inoculated with the same spore load. Brown rot was observed on wounded plums only. A substantial increase in lesion diameter of brown rot was also recorded on wounded nectarines and peaches inoculated with suspensions of ≤20 spores and ≤200 spores per wound, respectively, compared with unwounded fruit. At concentrations of 107 and 108 spores per ml, all Trichoderma isolates substantially reduced brown rot on peaches (63 to 98%) and plums (67 to 100%) when Fruits were inoculated with M. fructicola following the application of a biological control agent. Similar...
Robert P. Walker - One of the best experts on this subject based on the ideXlab platform.
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Non-structural Carbohydrate Metabolism in the Flesh of Stone Fruits of the Genus Prunus (Rosaceae) - A Review.
Frontiers in plant science, 2020Co-Authors: Robert P. Walker, Claudio Bonghi, María F. Drincovich, María V. Lara, Giannina Vizzotto, Alberto Battistelli, Rachele Falchi, Stefano Moscatello, Franco FamianiAbstract:Non-structural carbohydrates are abundant constituents of the ripe flesh of all Stone Fruits. The bulk of their content comprises sucrose, glucose, fructose and sorbitol. However, the abundance of each of these carbohydrates in the flesh differs between species, and also with its stage of development. In this article the import, subcellular compartmentation, contents, metabolism and functions of non-structural carbohydrates in the flesh of commercially cultivated Stone Fruits of the family Rosaceae are reviewed.
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Stone Fruits: Growth and Nitrogen and Organic Acid Metabolism in the Fruits and Seeds—A Review
Frontiers in plant science, 2020Co-Authors: Franco Famiani, Claudio Bonghi, Zhi-hui Chen, María F. Drincovich, Daniela Farinelli, María V. Lara, Simona Proietti, Adolfo Rosati, Giannina Vizzotto, Robert P. WalkerAbstract:Stone Fruits of the Rosaceae family consist of several distinct parts, and these include the flesh, woody endocarp and seed. To understand the metabolism of these Fruits it is necessary to have a knowledge of both their structure and growth characteristics. The nitrogen metabolism of the different tissues of Stone Fruits is interlinked. For example, there is an import and storage of nitrogenous compounds in the endocarp that then are exported in the seed. Moreover, there are links between the metabolism of nitrogen and that of malic and citric acids. In this article, the structure and growth characteristics, together with the import/export, contents, metabolism and functions of nitrogenous compounds and organic acids in the different part of Stone Fruits and their seeds are reviewed.
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Stone Fruits growth and nitrogen and organic acid metabolism in the Fruits and seeds a review
Frontiers in Plant Science, 2020Co-Authors: Franco Famiani, Claudio Bonghi, Zhi-hui Chen, María F. Drincovich, Daniela Farinelli, María V. Lara, Simona Proietti, Adolfo Rosati, Giannina Vizzotto, Robert P. WalkerAbstract:Stone Fruits of the Rosaceae family consist of several distinct parts, and these include the flesh, woody endocarp and seed. To understand the metabolism of these Fruits it is necessary to have a knowledge of both their structure and growth characteristics. The nitrogen metabolism of the different tissues of Stone Fruits is interlinked. For example, there is an import and storage of nitrogenous compounds in the endocarp that then are exported in the seed. Moreover, there are links between the metabolism of nitrogen and that of malic and citric acids. In this article, the structure and growth characteristics, together with the import/export, contents, metabolism and functions of nitrogenous compounds and organic acids in the different part of Stone Fruits and their seeds are reviewed.
E. L. Little - One of the best experts on this subject based on the ideXlab platform.
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Genetic characterization of Pseudomonas syringae pv. syringae strains from Stone Fruits in California.
Applied and environmental microbiology, 1998Co-Authors: E. L. Little, Richard M. Bostock, Bruce C. KirkpatrickAbstract:Strains of Pseudomonas syringae pv. syringae were isolated from healthy and diseased Stone fruit tissues sampled from 43 orchard sites in California in 1995 and 1996. These strains, together with P. syringae strains from other hosts and pathovars, were tested for pathogenicity and the presence of the syrB and syrC genes and were genetically characterized by using enterobacterial repetitive intergenic consensus (ERIC) primers and PCR. All 89 strains of P. syringae pv. syringae tested were moderately to highly pathogenic on Lovell peach seedlings regardless of the host of origin, while strains of other pathovars exhibited low or no pathogenicity. The 19 strains of P. syringae pv. syringae examined by restriction fragment length polymorphism analysis contained the syrB and syrC genes, whereas no hybridization occurred with 4 strains of other P. syringae pathovars. The P. syringae pv. syringae strains from Stone fruit, except for a strain from New Zealand, generated ERIC genomic fingerprints which shared four fragments of similar mobility. Of the P. syringae pv. syringae strains tested from other hosts, only strains from rose, kiwi, and pear generated genomic fingerprints that had the same four fragments as the Stone fruit strains. Analysis of the ERIC fingerprints from P. syringae pv. syringae strains showed that the strains isolated from Stone Fruits formed a distinct cluster separate from most of the strains isolated from other hosts. These results provide evidence of host specialization within the diverse pathovar P. syringae pv. syringae.