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Synan Abuqamar - One of the best experts on this subject based on the ideXlab platform.
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biological control of mango Dieback Disease caused by lasiodiplodia theobromae using streptomycete and non streptomycete actinobacteria in the united arab emirates
Frontiers in Microbiology, 2018Co-Authors: Fatima H Kamil, Esam Eldin Saeed, Khaled A Eltarabily, Synan AbuqamarAbstract:Dieback caused by the fungus Lasiodiplodia theobromae is an important Disease on mango plantations in the United Arab Emirates (UAE). In this study, 53 actinobacterial isolates were obtained from mango rhizosphere soil in the UAE, of which 35 (66%) were classified as streptomycetes (SA) and 18 (34%) as non-streptomycetes (NSA). Among these isolates, 19 (12 SA and 7 NSA) showed antagonistic activities against L. theobromae associated with either the production of diffusible antifungal metabolites, extracellular cell-wall-degrading enzymes (CWDEs), or both. Using a “novel” mango fruit bioassay, all isolates were screened in vivo for their abilities to reduce lesion severity on fruits inoculated with L. theobromae. Three isolates, two belonging to Streptomyces and one to Micromonospora spp., showed the strongest inhibitory effect against this pathogen in vitro and were therefore selected for tests on mango seedlings. Our results revealed that the antifungal action of S. samsunensis UAE1 was related to antibiosis, and the production of CWDEs (i.e., chitinase) and siderophores; whilst S. cavourensis UAE1 and M. tulbaghiae UAE1 were considered to be associated with antibiotic- and CWDE-production, respectively. Pre-inoculation in greenhouse experiments with the most promising actinobacterial isolates resulted in very high levels of Disease protection in mango seedlings subsequently inoculated with the pathogen. This was evident by the dramatic reduction in the estimated Disease severity indices of the mango Dieback of individual biocontrol agent (BCA) applications compared with the pathogen alone, confirming their potential in the management of mango Dieback Disease. L. theobromae-infected mango seedlings treated with S. samsunensis showed significantly reduced number of defoliated leaves and conidia counts of L. theobromae by 2- and 4-fold, respectively, in comparison to the other two BCA applications. This indicates that the synergistic antifungal effects of S. samsunensis using multiple modes of action retarded the in planta invasion of L. theobromae. This is the first report of BCA effects against L. theobromae on mango seedlings by microbial antagonists. It is also the first report of actinobacteria naturally existing in the soils of the UAE or elsewhere that show the ability to suppress the mango Dieback Disease.
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detection and management of mango Dieback Disease in the united arab emirates
International Journal of Molecular Sciences, 2017Co-Authors: Esam Eldin Saeed, Arjun Sham, Ayah Abuzarqa, Khawla Al A Shurafa, Tahra Al S Naqbi, Rabah Iratni, Khaled A Eltarabily, Synan AbuqamarAbstract:Mango is affected by different decline disorders causing significant losses to mango growers. In the United Arab Emirates (UAE), the pathogen was isolated from all tissues sampled from Diseased trees affected by Lasiodiplodia theobromae. Symptoms at early stages of the Disease included general wilting appearance of mango trees, and Dieback of twigs. In advanced stages, the Disease symptoms were also characterized by the curling and drying of leaves, leading to complete defoliation of the tree and discolouration of vascular regions of the stems and branches. To substantially reduce the devastating impact of Dieback Disease on mango, the fungus was first identified based on its morphological and cultural characteristics. Target regions of 5.8S rRNA (ITS) and elongation factor 1-α (EF1-α) genes of the pathogen were amplified and sequenced. We also found that the systemic chemical fungicides, Score®, Cidely® Top, and Penthiopyrad®, significantly inhibited the mycelial growth of L. theobromae both in vitro and in the greenhouse. Cidely® Top proved to be a highly effective fungicide against L. theobromae Dieback Disease also under field conditions. Altogether, the morphology of the fruiting structures, molecular identification and pathogenicity tests confirm that the causal agent of the mango Dieback Disease in the UAE is L. theobromae.
Khaled A Eltarabily - One of the best experts on this subject based on the ideXlab platform.
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biological control of mango Dieback Disease caused by lasiodiplodia theobromae using streptomycete and non streptomycete actinobacteria in the united arab emirates
Frontiers in Microbiology, 2018Co-Authors: Fatima H Kamil, Esam Eldin Saeed, Khaled A Eltarabily, Synan AbuqamarAbstract:Dieback caused by the fungus Lasiodiplodia theobromae is an important Disease on mango plantations in the United Arab Emirates (UAE). In this study, 53 actinobacterial isolates were obtained from mango rhizosphere soil in the UAE, of which 35 (66%) were classified as streptomycetes (SA) and 18 (34%) as non-streptomycetes (NSA). Among these isolates, 19 (12 SA and 7 NSA) showed antagonistic activities against L. theobromae associated with either the production of diffusible antifungal metabolites, extracellular cell-wall-degrading enzymes (CWDEs), or both. Using a “novel” mango fruit bioassay, all isolates were screened in vivo for their abilities to reduce lesion severity on fruits inoculated with L. theobromae. Three isolates, two belonging to Streptomyces and one to Micromonospora spp., showed the strongest inhibitory effect against this pathogen in vitro and were therefore selected for tests on mango seedlings. Our results revealed that the antifungal action of S. samsunensis UAE1 was related to antibiosis, and the production of CWDEs (i.e., chitinase) and siderophores; whilst S. cavourensis UAE1 and M. tulbaghiae UAE1 were considered to be associated with antibiotic- and CWDE-production, respectively. Pre-inoculation in greenhouse experiments with the most promising actinobacterial isolates resulted in very high levels of Disease protection in mango seedlings subsequently inoculated with the pathogen. This was evident by the dramatic reduction in the estimated Disease severity indices of the mango Dieback of individual biocontrol agent (BCA) applications compared with the pathogen alone, confirming their potential in the management of mango Dieback Disease. L. theobromae-infected mango seedlings treated with S. samsunensis showed significantly reduced number of defoliated leaves and conidia counts of L. theobromae by 2- and 4-fold, respectively, in comparison to the other two BCA applications. This indicates that the synergistic antifungal effects of S. samsunensis using multiple modes of action retarded the in planta invasion of L. theobromae. This is the first report of BCA effects against L. theobromae on mango seedlings by microbial antagonists. It is also the first report of actinobacteria naturally existing in the soils of the UAE or elsewhere that show the ability to suppress the mango Dieback Disease.
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detection and management of mango Dieback Disease in the united arab emirates
International Journal of Molecular Sciences, 2017Co-Authors: Esam Eldin Saeed, Arjun Sham, Ayah Abuzarqa, Khawla Al A Shurafa, Tahra Al S Naqbi, Rabah Iratni, Khaled A Eltarabily, Synan AbuqamarAbstract:Mango is affected by different decline disorders causing significant losses to mango growers. In the United Arab Emirates (UAE), the pathogen was isolated from all tissues sampled from Diseased trees affected by Lasiodiplodia theobromae. Symptoms at early stages of the Disease included general wilting appearance of mango trees, and Dieback of twigs. In advanced stages, the Disease symptoms were also characterized by the curling and drying of leaves, leading to complete defoliation of the tree and discolouration of vascular regions of the stems and branches. To substantially reduce the devastating impact of Dieback Disease on mango, the fungus was first identified based on its morphological and cultural characteristics. Target regions of 5.8S rRNA (ITS) and elongation factor 1-α (EF1-α) genes of the pathogen were amplified and sequenced. We also found that the systemic chemical fungicides, Score®, Cidely® Top, and Penthiopyrad®, significantly inhibited the mycelial growth of L. theobromae both in vitro and in the greenhouse. Cidely® Top proved to be a highly effective fungicide against L. theobromae Dieback Disease also under field conditions. Altogether, the morphology of the fruiting structures, molecular identification and pathogenicity tests confirm that the causal agent of the mango Dieback Disease in the UAE is L. theobromae.
David J Studholme - One of the best experts on this subject based on the ideXlab platform.
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draft genome sequence of pseudomonas syringae pathovar syringae strain ff5 causal agent of stem tip Dieback Disease on ornamental pear
Journal of Bacteriology, 2012Co-Authors: Kee Hoon Sohn, Jonathan D G Jones, David J StudholmeAbstract:Pseudomonas syringae FF5 causes stem tip Dieback Disease on ornamental pear (Pyrus calleryana). Its genome encodes a complete type III secretion system (T3SS) and HopAC1, HopM1, AvrE1, HopI1, HopAA1, HopJ1, HopAH2, HopAH1, HopAG1, and HopAZ1. Lacking detectable homologues of other T3SS effectors, it may encode novel, undiscovered effectors.
Esam Eldin Saeed - One of the best experts on this subject based on the ideXlab platform.
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biological control of mango Dieback Disease caused by lasiodiplodia theobromae using streptomycete and non streptomycete actinobacteria in the united arab emirates
Frontiers in Microbiology, 2018Co-Authors: Fatima H Kamil, Esam Eldin Saeed, Khaled A Eltarabily, Synan AbuqamarAbstract:Dieback caused by the fungus Lasiodiplodia theobromae is an important Disease on mango plantations in the United Arab Emirates (UAE). In this study, 53 actinobacterial isolates were obtained from mango rhizosphere soil in the UAE, of which 35 (66%) were classified as streptomycetes (SA) and 18 (34%) as non-streptomycetes (NSA). Among these isolates, 19 (12 SA and 7 NSA) showed antagonistic activities against L. theobromae associated with either the production of diffusible antifungal metabolites, extracellular cell-wall-degrading enzymes (CWDEs), or both. Using a “novel” mango fruit bioassay, all isolates were screened in vivo for their abilities to reduce lesion severity on fruits inoculated with L. theobromae. Three isolates, two belonging to Streptomyces and one to Micromonospora spp., showed the strongest inhibitory effect against this pathogen in vitro and were therefore selected for tests on mango seedlings. Our results revealed that the antifungal action of S. samsunensis UAE1 was related to antibiosis, and the production of CWDEs (i.e., chitinase) and siderophores; whilst S. cavourensis UAE1 and M. tulbaghiae UAE1 were considered to be associated with antibiotic- and CWDE-production, respectively. Pre-inoculation in greenhouse experiments with the most promising actinobacterial isolates resulted in very high levels of Disease protection in mango seedlings subsequently inoculated with the pathogen. This was evident by the dramatic reduction in the estimated Disease severity indices of the mango Dieback of individual biocontrol agent (BCA) applications compared with the pathogen alone, confirming their potential in the management of mango Dieback Disease. L. theobromae-infected mango seedlings treated with S. samsunensis showed significantly reduced number of defoliated leaves and conidia counts of L. theobromae by 2- and 4-fold, respectively, in comparison to the other two BCA applications. This indicates that the synergistic antifungal effects of S. samsunensis using multiple modes of action retarded the in planta invasion of L. theobromae. This is the first report of BCA effects against L. theobromae on mango seedlings by microbial antagonists. It is also the first report of actinobacteria naturally existing in the soils of the UAE or elsewhere that show the ability to suppress the mango Dieback Disease.
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detection and management of mango Dieback Disease in the united arab emirates
International Journal of Molecular Sciences, 2017Co-Authors: Esam Eldin Saeed, Arjun Sham, Ayah Abuzarqa, Khawla Al A Shurafa, Tahra Al S Naqbi, Rabah Iratni, Khaled A Eltarabily, Synan AbuqamarAbstract:Mango is affected by different decline disorders causing significant losses to mango growers. In the United Arab Emirates (UAE), the pathogen was isolated from all tissues sampled from Diseased trees affected by Lasiodiplodia theobromae. Symptoms at early stages of the Disease included general wilting appearance of mango trees, and Dieback of twigs. In advanced stages, the Disease symptoms were also characterized by the curling and drying of leaves, leading to complete defoliation of the tree and discolouration of vascular regions of the stems and branches. To substantially reduce the devastating impact of Dieback Disease on mango, the fungus was first identified based on its morphological and cultural characteristics. Target regions of 5.8S rRNA (ITS) and elongation factor 1-α (EF1-α) genes of the pathogen were amplified and sequenced. We also found that the systemic chemical fungicides, Score®, Cidely® Top, and Penthiopyrad®, significantly inhibited the mycelial growth of L. theobromae both in vitro and in the greenhouse. Cidely® Top proved to be a highly effective fungicide against L. theobromae Dieback Disease also under field conditions. Altogether, the morphology of the fruiting structures, molecular identification and pathogenicity tests confirm that the causal agent of the mango Dieback Disease in the UAE is L. theobromae.
Pablo S Lara - One of the best experts on this subject based on the ideXlab platform.
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the resistance of mango mangifera indica cultivars to tip Dieback Disease in florida
Plant Disease, 1997Co-Authors: Leandro J Ramos, Thomas L Davenport, Robert T Mcmillan, Pablo S LaraAbstract:ABSTRACT The resistance of Mangifera indica to tip Dieback Disease caused by Botryosphaeria ribis, anamorphic state Fusicoccum sp., was determined on 361 trees of 122 mango cultivars and relatives planted in the mango germ plasm collection at the University of Florida, Tropical Research and Education Center, Homestead. Three trees from each cultivar were evaluated on a 1 to 5 scale ranging from those free of tip Dieback to those with extensive branch necrosis. Each cultivar was assigned to one of eight major systematic groups based on race or geographic origin. Resistance to tip Dieback Disease was not associated with any of the groups. No significant differences in mean Disease severity were found among the Indian, Southeast Asian, West Indian, Haden, or Sandersha parts of the Haden-Sandersha Complex, Turpentine types, or a group of unclassified cultivars. Two Mangifera species (M. odorata and M. zeylanica) showed the lowest mean Disease rating. Cultivars were also grouped into monoembryonic and polyembr...