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Browsing Mathematics by Author "Abate Dawit (PhD)"

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    Ergot Fungus (Claviceps Purpurea), Ergot Alkaloids and Ergotism in the Central Highlands of Arsi, Ethiopia
    (Addis Ababa University, 2017-12-03) Desalegn Asnake; Abate Dawit (PhD)
    Ergot fungi, Claviceps species, parasitize several monocot plants and produce a hardened dark to dark-purple structure called the sclerotia. In Ethiopia, the ergot fungus infects only the wild oat plant (Avena abyssinica) which is endemic to Ethiopia and Yemen. Ergot alkaloids produced in the sclerotia of the ergot fungus, were responsible for mass poisoning in various areas of the world, with the most recent report of mass poisoning in Arsi, Ethiopia. This study was initiated with the objectives of identifying the ergot fungus (Claviceps purpurea) based on morphological and molecular characteristics, ergot alkaloids, and assessing the knowledge of study participants about ergot fungus and ergotism from the previously reported outbreaks areas of Arsi, Ethiopia. Dimensions of the sexual and asexual structures were studied and statistically significant differences (n = 30, P < 0.001) in the length and width of sclerotia collected from the study sites Kechema Murkicha, Bucho Selassie and Shaldo Jigessa were observed. Dimensions of sclerotia collected from all the study sites significantly differed (p < 0.001) from the dimensions of wild oats seeds (n = 30). But, statistically significant differences were not observed (p > 0.05) for the dimensions of conidia of ergot fungi collected from different study sites. Growth (100%) of the sexual stage occurred only on Petri dishes incubated for 21 days at 5 OC followed by incubation at 25 OC. No growth was observed on the Petri dishes incubated under other temperature treatments. The mean length of stromata ranged from 18.5 mm to 19mm and the mean diameter of capitula ranged from 1.8 mm to 2mm. Cylindrical to flask shaped perithecia with mean length and width of 158.8 ± 3.7 μm and 89.2 ± 1.7 μm, and filiform shaped ascospores with mean length and width of 77.1 ± 3.7 μm and 3.3 ± 0.5 μm respectively were observed. Phylogenetic analysis of the β-tubulin intron 3 region using maximum parsimony placed our isolates in a separate cluster with strong bootstrap value of 94. Qualitative studies of the ergot alkaloids using UPLC-QTOF High Definition Mass Spectrometery revealed the presence of ergometrine, ergocryptine, ergocornine, ergosine, ergovaline, lysergyl alanine, lysergyl valine, valine methyl ester, their respective -innine isomers and an ergopeptam (ergocryptam). A crosssectional study conducted to assess the awareness of study participants recruited from Tijo, Digelu and Kechema areas, Arsi, Ethiopia, showed lack of awareness about the fungus and the disease it causes. Among the study participants who were shown the coloured picture of ergot fungus, majority 55 (32.7%) described its name as ‘Sinara Guracha’ which is synonymous with “Black wild ii oat”. A multiple logistic regression model fitted revealed statistically significant association of the study sites with knowledge of ergot (p < 0.05). Finally, morphological and molecular characteristics placed the ergot fungi in the current study under Claviceps purpurea. The presence of the Claviceps purpurea in farmers’ field, detection of additional toxic ergot alkaloids and lack of awareness of the study participants about the ergot fungus, Claviceps purpurea, are the potential risks for the community.