Pathogenicity of Xanthomonas campestris pv. allii causing bacterial leaf blight of onion in sudan and antibacterial efficacy of plant extracts
| Autor: | Omer O A Albashir, Amal Y M Albadawi, Yousif O. H. Assad |
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| Rok vydání: | 2017 |
| Předmět: | |
| Zdroj: | Agricultural Research Journal. 54:523 |
| ISSN: | 2395-146X 2395-1435 |
| DOI: | 10.5958/2395-146x.2017.00100.4 |
| Popis: | Bacterial leaf blight of onion, caused by Xanthomonas campestris pv. allii, is a new disease of green bulb onion in Sudan. A study was conducted to test pathogenicity of the causative agent of onion bacterial leaf blight and evaluate the efficacy of certain plant extracts against the pathogen. Antibacterial activity of aqueous ethanolic plant extracts of desert rose (Adenium obesum), eucalyptus (Eucalyptus microtheca), button wood (Conocarpus erectus), tamarind (Tamarindus indica) and mesquite (Prosopis julifora), at different concentrations, was assayed in vitro by well diffusion technique. The bacterium X. campestris pv. allii was isolated from leaf lesions and its pathogenicity was confirmed on onion leaves. There were significant differences between the extracts in their effect on bacterial growth and the best results were obtained at a high concentration (420 ppm) of plant extracts. Among the test plant extracts, mesquite extract revealed a high anti-bacterial activity with inhibition zone up to 38.6 mm. It was followed by eucalyptus extract with inhibition zone of 38.3mm, button wood and tamarind with inhibition zone of 38 mm each. Desert rose extract displayed lower inhibition zone of 20.2 mm as dcompare to the standard control of stryptomicin having inhibition zone of 36 mm. Thus plant extracts of eucalyptus, mesquite, button wood, and tamarind were promising and may help in the non-toxic, eco-friendly management of onion bacterial leaf blight disease. |
| Databáze: | OpenAIRE |
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