Pathotypes Characterization and Virulence Diversity of Pseudocercospora griseola the Causal Agent of Angular Leaf Spot Disease Collected from Major Common Bean (Phaseolus vulgaris L.) Growing Areas of Ethiopia

Angular leaf spot (ALS) caused by the fungus Pseudocercospora griseola is one of the most economically important disease affecting common bean production in Ethiopia. Until now, no information has been generated regarding the pathotype and pathogenic variability and its distribution in Ethiopia. A study was undertaken to characterize the pathotype and virulence variability among 39 P. griseola isolates, ALS pathogen, occurring in Ethiopia. A total of 21 pathotypes (63:63, 63:59, 63:23, 61:51, 56:36, 55:39, 49:7, 48:60, 42:59, 41:10, 34:53, 23:61, 19:33, 17:45, 8:18, 8:0, 4:16, 1:24, 1:10, 16:18. and 4:37) were determined using 12 sets of ALS common bean differentials cultivars. These results revealed the presence of high and diverse pathogenic variability of the pathogen. Among the determined pathotypes 63:59 and 19:33 were the most frequently appeared. And the occurrence of three pathotypes (63:63, 63:59 and 63:23) were confirmed as well as the previous reports in central America and Argentina. This will be the first comprehensive report of P. griseola pathotypes existing in the common bean growing areas of Ethiopia. Except pathotype 8:0 that were compatible with Andean common bean groups, most of the isolates were pathogenic to both Andean and Mesoamerican common bean gene pools. Based on that, the isolates were classified as Mesoamerican origin pathotypes. This specific study provided major information about the pathogenic diversity and determined the pathotype of P. griseola from common bean in Ethiopia.