Physiological characterization and evaluation of common bean genotypes against anthracnose (Colletotrichum lindemuthianum (Sacc. and Magnus) Lams-Scriber) races in West Shewa, Ethiopia
Authors: Yohannes Keterew1*, Woubit Dawit2, Thangavel Selvaraj2 and Alemu Lencho2
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Common bean (Phaseolus vulgaris L.) is an important legume crop in the daily diet and good source of cash and food nutrients. Despite its economic significance, anthracnose disease caused by Colletotrichum lindemuthianum (Sacc. and Magnus) Lams-Scriber is one of the most destructive diseases and causes significant yield losses in common bean growing areas. The pathogen possesses a very high degree of pathogenic variability, but there are lack of knowledge of population race structure and variability of the pathogen in West Shewa Zone, Ethiopia. Therefore, the present study was conducted to identify C. lindemuthianum races and evaluation of common bean genotypes against the virulent isolates. Race analysis was carried out by inoculating 51 isolates on to the 12 differential hosts. Among 51 isolates, 15 physiological races were identified and designated as races 19, 67, 68, 73, 82, 99, 128, 154, 296, 389, 589, 649, 1033, 1403 and 1703 of which 10 of them (19, 67, 82, 99, 154, 389, 649, 1033, 1403 and 1703) were new races identified for the first time in Ethiopia. The most virulent race was 1703 made seven differential hosts’ resistant genes ineffective and the least virulent race was 128, which conquer only one resistant gene of the differential cultivar. There were no races found to be pathogenic to differential cultivar G2333 and the differential cultivar, Michelite was found to be the most susceptible with virulence gene frequency of 64.7%. Besides, differential cultivar Widusa, TO and AB136 were highly resistant while G2333 was the highest resistant to all isolates. Among 36 common bean genotypes screened against seven virulent races, 19.4% were resistant and 16.2% highly susceptible to the virulent races. Thus, the effective differential cultivars and common bean genotypes could serve as sources of resistant genes under West Shewa Zone, Ethiopia. In general, the results of this study are very promising for enhancing common bean production and improving food security in study area.