The Experts below are selected from a list of 174 Experts worldwide ranked by ideXlab platform
S Hasan - One of the best experts on this subject based on the ideXlab platform.
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axenic culture and influence of wetness period and inoculum concentration on infection and development of cercospora blight of Heliotropium europaeum
European Journal of Plant Pathology, 1995Co-Authors: S Hasan, L Brun, M Jourdan, A W SheppardAbstract:Cercospora heliotropii-bocconii is a fungal pathogen of the ephemeral annual weedHeliotropium europaeum. The effects of wetness period and inoculum concentration on disease severity were studied under controlled conditions. The fungus was grown on different artificial culture media and carrot juice agar with 5 g l−1 yeast extract was found to be the most suitable medium for conidial production under artificial conditions. Abundant disease symptoms only occurred after 8 h of wetness at 20°C. The minimum incubation period before disease symptoms appeared was 8 days following a wetness period of at least 40 h. Inoculum concentration of 1×104 conidia per ml killed plants in less than one month and reduced seed production by two thirds. These results suggest that this pathogen has the potential to reduce plant survival and seed bank replenishment of this annual weed species.
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Axenic culture and influence of wetness period and inoculum concentration on infection and development of cercospora blight ofHeliotropium europaeum
European Journal of Plant Pathology, 1995Co-Authors: S Hasan, L Brun, M Jourdan, A W SheppardAbstract:Cercospora heliotropii-bocconii is a fungal pathogen of the ephemeral annual weed Heliotropium europaeum . The effects of wetness period and inoculum concentration on disease severity were studied under controlled conditions. The fungus was grown on different artificial culture media and carrot juice agar with 5 g l^−1 yeast extract was found to be the most suitable medium for conidial production under artificial conditions. Abundant disease symptoms only occurred after 8 h of wetness at 20°C. The minimum incubation period before disease symptoms appeared was 8 days following a wetness period of at least 40 h. Inoculum concentration of 1×10^4 conidia per ml killed plants in less than one month and reduced seed production by two thirds. These results suggest that this pathogen has the potential to reduce plant survival and seed bank replenishment of this annual weed species.
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development of cercospora blight epidemics and effect on the summer annual Heliotropium europaeum in the field
Annals of Applied Biology, 1995Co-Authors: L Brun, S Hasan, A W Sheppard, E Delmotte, M JourdanAbstract:Summary Heliotropium europaeum, common heliotrope, is a serious economic weed in southern Australia. Cercospora blight occurs on H. europaeum in both its native (Mediterranean) and non-native (Australian) range. The causal agents are genetically different forms of an asexual pathogen in the form-genus Cercospora in each region. Natural epidemics of cercospora blight killed weed infestations in both Australia and France. The epidemiology of the disease did not differ between the two regions once differences in rainfall had been considered. Rainfall was important for disease spread. In France, field inoculation experiments were conducted using different concentrations of conidia prepared from a monospore isolate. Cercospora blight reduced seed production 89%, but did not reduce viability. Increased inoculum concentration and inoculation of younger plants encouraged an early epidemic, but did not affect the rate of disease development once the epidemic took hold. In order to be effective at controlling this weed in Australia, these pathogens need to attack young hosts and have regular rain-splash to facilitate spread to new growth.
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susceptibility of the australian native Heliotropium crispatum to the rust fungus uromyces heliotropii introduced to control common heliotrope Heliotropium europaeum
Biocontrol Science and Technology, 1995Co-Authors: S Hasan, E S DelfosseAbstract:During host-specificity tests of the rust Uromyces heliotropii carried out in Europe against a range of cultivated and wild plants, two species of European heliotropes closely related to the summer annual weed, common heliotrope (Heliotropium europaeum) and one native to Australia, H. crispatum, were found to be susceptible. Detailed observations were made of the degree of infection, the climatic requirements, the attenuation of virulence over time and the low probability of spore transmission for infection. These results, in addition to the scattered, relatively uncommon occurrence of H. crispatum in the field, showed that the plant was unlikely to be adversely affected by the rust, which has been released in Australia to control common heliotrope infestations.
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host specificity of uromyces heliotropii a fungal agent for the biological control of common heliotrope Heliotropium europaeum in australia
Annals of Applied Biology, 1992Co-Authors: S Hasan, E Aracil, E S Delfosse, R C LewisAbstract:Summary Common heliotrope, Heliotropium europaeum (Boraginaceae), a summer annual, is a serious weed of pastures in Australia causing poisoning in sheep and other grazing animals. The weed is native to Mediterranean and Middle Eastern regions of Eurasia where it is attacked by several arthropods and pathogens including the rust fungus Uromyces heliotropii. The host-specificity of a virulent and effective strain of the rust from Turkey has been tested by inoculating 96 plants of importance to the Australasian region using both microscopic and macroscopic observations of the reaction of host and non-host plants. The test plants included several members of the Boraginaceae and related families as well as species of Heliotropium native to Australia. The infection was mostly limited to European species of Heliotropium. U. heliotropii was thus found to represent a safe introduction and has recently been introduced to Australia for the biological control of common heliotrope.
E Aracil - One of the best experts on this subject based on the ideXlab platform.
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Host‐specificity of Uromyces heliotropii, a fungal agent for the biological control of common heliotrope (Heliotropium europaeum) in Australia
Annals of Applied Biology, 1992Co-Authors: S Hasan, E Aracil, E S Delfosse, R C LewisAbstract:Summary Common heliotrope, Heliotropium europaeum (Boraginaceae), a summer annual, is a serious weed of pastures in Australia causing poisoning in sheep and other grazing animals. The weed is native to Mediterranean and Middle Eastern regions of Eurasia where it is attacked by several arthropods and pathogens including the rust fungus Uromyces heliotropii. The host-specificity of a virulent and effective strain of the rust from Turkey has been tested by inoculating 96 plants of importance to the Australasian region using both microscopic and macroscopic observations of the reaction of host and non-host plants. The test plants included several members of the Boraginaceae and related families as well as species of Heliotropium native to Australia. The infection was mostly limited to European species of Heliotropium. U. heliotropii was thus found to represent a safe introduction and has recently been introduced to Australia for the biological control of common heliotrope.
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host specificity of uromyces heliotropii a fungal agent for the biological control of common heliotrope Heliotropium europaeum in australia
Annals of Applied Biology, 1992Co-Authors: S Hasan, E Aracil, E S Delfosse, R C LewisAbstract:Summary Common heliotrope, Heliotropium europaeum (Boraginaceae), a summer annual, is a serious weed of pastures in Australia causing poisoning in sheep and other grazing animals. The weed is native to Mediterranean and Middle Eastern regions of Eurasia where it is attacked by several arthropods and pathogens including the rust fungus Uromyces heliotropii. The host-specificity of a virulent and effective strain of the rust from Turkey has been tested by inoculating 96 plants of importance to the Australasian region using both microscopic and macroscopic observations of the reaction of host and non-host plants. The test plants included several members of the Boraginaceae and related families as well as species of Heliotropium native to Australia. The infection was mostly limited to European species of Heliotropium. U. heliotropii was thus found to represent a safe introduction and has recently been introduced to Australia for the biological control of common heliotrope.
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biology and effectiveness of uromyces heliotropii sred a potential biological control agent of Heliotropium europaeum l
New Phytologist, 1991Co-Authors: S Hasan, E AracilAbstract:summary The rust fungus Uromyces hellotropii Sred. shows potential for the biological control in Australia of the common heliotrope (Heliotropium europaeum L.), an annual weed of European origin. Teliospores of the pathogen remained viable when stored for one year at temperatures between −8 and 20°C, and carried infection over from one summer growing season to the next under a Mediterranean-like climate. Both in glasshouse and field inoculation experiments, the rust rapidly killed infected plants and reduced or prevented seed production. U. heliotropii appears capable of surviving in the Mediterranean-like climatic areas of Australia where common heliotrope is a problem weed and is sufficiently virulent to cause significant field infection.
Jakob A Shimshoni - One of the best experts on this subject based on the ideXlab platform.
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detection of pyrrolizidine alkaloid dna adducts in livers of cattle poisoned with Heliotropium europaeum
Chemical Research in Toxicology, 2017Co-Authors: Peter P Fu, Nir Edery, Shimon Barel, Xiaobo He, Frederick A Beland, Jakob A ShimshoniAbstract:Pyrrolizidine alkaloids are among the most common poisonous plants affecting livestock, wildlife, and humans. Exposure of humans and livestock to toxic pyrrolizidine alkaloids through the intake of contaminated food and feed may result in poisoning, leading to devastating epidemics. During February 2014, 73 mixed breed female beef cows from the Galilee region of Israel were accidently fed pyrrolizidine alkaloid contaminated hay for 42 days, resulting in the sudden death of 24 cows over a period of 63 days. The remaining cows were slaughtered 2.5 months after the last ingestion of the contaminated hay. In this study, we report the histopathological analysis of the livers from five of the slaughtered cows and quantitation of pyrrolizidine alkaloid-derived DNA adducts from their livers and three livers of control cows fed with feed free of weeds producing pyrrolizidine alkaloids. Histopathological examination revealed that the five cows suffered from varying degrees of bile duct proliferation, fibrosis, and ...
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Heliotropium europaeum poisoning in cattle and analysis of its pyrrolizidine alkaloid profile
Journal of Agricultural and Food Chemistry, 2015Co-Authors: Jakob A Shimshoni, Patrick P J Mulder, Arieli Bouznach, Nir Edery, Israel Pasval, Shimon Barel, Mohammed Abdel Khaliq, S PerlAbstract:Pyrrolizidine alkaloids (PAs) are carcinogenic and genotoxic phytochemicals found exclusively in angiosperms. The ingestion of PA-containing plants often results in acute and chronic toxicities in man and livestock, targeting mainly the liver. During February 2014, a herd of 15–18-month-old mixed-breed beef cattle (n = 73) from the Galilee region in Israel was accidently fed hay contaminated with 12% Heliotropium europaeum (average total PA intake was 33 mg PA/kg body weight/d). After 42 d of feed ingestion, sudden death occurred over a time period of 63 d with a mortality rate of 33%. Necropsy and histopathological examination revealed fibrotic livers and moderate ascites, as well as various degrees of hyperplasia and fibrosis of bile duct epithelial cells. Elevated γ-glutamyl-transferase and alkaline phosphatase levels were indicative of severe liver damage. Comprehensive PA profile determination of the contaminated hay and of native H. europaeum by LC–MS/MS revealed the presence of 30 PAs and PA-N-oxid...
M Jourdan - One of the best experts on this subject based on the ideXlab platform.
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axenic culture and influence of wetness period and inoculum concentration on infection and development of cercospora blight of Heliotropium europaeum
European Journal of Plant Pathology, 1995Co-Authors: S Hasan, L Brun, M Jourdan, A W SheppardAbstract:Cercospora heliotropii-bocconii is a fungal pathogen of the ephemeral annual weedHeliotropium europaeum. The effects of wetness period and inoculum concentration on disease severity were studied under controlled conditions. The fungus was grown on different artificial culture media and carrot juice agar with 5 g l−1 yeast extract was found to be the most suitable medium for conidial production under artificial conditions. Abundant disease symptoms only occurred after 8 h of wetness at 20°C. The minimum incubation period before disease symptoms appeared was 8 days following a wetness period of at least 40 h. Inoculum concentration of 1×104 conidia per ml killed plants in less than one month and reduced seed production by two thirds. These results suggest that this pathogen has the potential to reduce plant survival and seed bank replenishment of this annual weed species.
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Axenic culture and influence of wetness period and inoculum concentration on infection and development of cercospora blight ofHeliotropium europaeum
European Journal of Plant Pathology, 1995Co-Authors: S Hasan, L Brun, M Jourdan, A W SheppardAbstract:Cercospora heliotropii-bocconii is a fungal pathogen of the ephemeral annual weed Heliotropium europaeum . The effects of wetness period and inoculum concentration on disease severity were studied under controlled conditions. The fungus was grown on different artificial culture media and carrot juice agar with 5 g l^−1 yeast extract was found to be the most suitable medium for conidial production under artificial conditions. Abundant disease symptoms only occurred after 8 h of wetness at 20°C. The minimum incubation period before disease symptoms appeared was 8 days following a wetness period of at least 40 h. Inoculum concentration of 1×10^4 conidia per ml killed plants in less than one month and reduced seed production by two thirds. These results suggest that this pathogen has the potential to reduce plant survival and seed bank replenishment of this annual weed species.
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development of cercospora blight epidemics and effect on the summer annual Heliotropium europaeum in the field
Annals of Applied Biology, 1995Co-Authors: L Brun, S Hasan, A W Sheppard, E Delmotte, M JourdanAbstract:Summary Heliotropium europaeum, common heliotrope, is a serious economic weed in southern Australia. Cercospora blight occurs on H. europaeum in both its native (Mediterranean) and non-native (Australian) range. The causal agents are genetically different forms of an asexual pathogen in the form-genus Cercospora in each region. Natural epidemics of cercospora blight killed weed infestations in both Australia and France. The epidemiology of the disease did not differ between the two regions once differences in rainfall had been considered. Rainfall was important for disease spread. In France, field inoculation experiments were conducted using different concentrations of conidia prepared from a monospore isolate. Cercospora blight reduced seed production 89%, but did not reduce viability. Increased inoculum concentration and inoculation of younger plants encouraged an early epidemic, but did not affect the rate of disease development once the epidemic took hold. In order to be effective at controlling this weed in Australia, these pathogens need to attack young hosts and have regular rain-splash to facilitate spread to new growth.
R C Lewis - One of the best experts on this subject based on the ideXlab platform.
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host specificity of uromyces heliotropii a fungal agent for the biological control of common heliotrope Heliotropium europaeum in australia
Annals of Applied Biology, 1992Co-Authors: S Hasan, E Aracil, E S Delfosse, R C LewisAbstract:Summary Common heliotrope, Heliotropium europaeum (Boraginaceae), a summer annual, is a serious weed of pastures in Australia causing poisoning in sheep and other grazing animals. The weed is native to Mediterranean and Middle Eastern regions of Eurasia where it is attacked by several arthropods and pathogens including the rust fungus Uromyces heliotropii. The host-specificity of a virulent and effective strain of the rust from Turkey has been tested by inoculating 96 plants of importance to the Australasian region using both microscopic and macroscopic observations of the reaction of host and non-host plants. The test plants included several members of the Boraginaceae and related families as well as species of Heliotropium native to Australia. The infection was mostly limited to European species of Heliotropium. U. heliotropii was thus found to represent a safe introduction and has recently been introduced to Australia for the biological control of common heliotrope.
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Host‐specificity of Uromyces heliotropii, a fungal agent for the biological control of common heliotrope (Heliotropium europaeum) in Australia
Annals of Applied Biology, 1992Co-Authors: S Hasan, E Aracil, E S Delfosse, R C LewisAbstract:Summary Common heliotrope, Heliotropium europaeum (Boraginaceae), a summer annual, is a serious weed of pastures in Australia causing poisoning in sheep and other grazing animals. The weed is native to Mediterranean and Middle Eastern regions of Eurasia where it is attacked by several arthropods and pathogens including the rust fungus Uromyces heliotropii. The host-specificity of a virulent and effective strain of the rust from Turkey has been tested by inoculating 96 plants of importance to the Australasian region using both microscopic and macroscopic observations of the reaction of host and non-host plants. The test plants included several members of the Boraginaceae and related families as well as species of Heliotropium native to Australia. The infection was mostly limited to European species of Heliotropium. U. heliotropii was thus found to represent a safe introduction and has recently been introduced to Australia for the biological control of common heliotrope.