A review of Pseudocercospora griseola in common bean ( Phaseolus vulgaris L.) in Africa

Abstract

Angular leaf spot (ALS), caused by the fungus Pseudocercospora griseola , is one of the most economically important diseases that limits the productivity of common beans. P. griseola has great variability which explains the large number of existing races and the complexity of genetic resistance. This review was carried out to discuss and document on the diversity of P. griseola in Africa , and the pathogenic variability of pathotypes against different bean varieties and lines. Diversified pathotypes were identified from different common bean-growing countries. About 12 pathotypes were identified from 45 isolates in Uganda. Similarly, about 44 pathotypes were characterized from 100 isolates in Kenya. Pathotypes 61:63 and 63:63 were the most aggressive identified pathotypes in different African countries. Many reports indicated that Andean isolates infect mostly Andean genotypes, while Mesoamerican isolates infect both Andean and Mesoamerican genotypes. The resistances of major commercial varieties and bean lines are breaking down and were found to be susceptible. Hence, multiple resistance breeding should be done for broken commercial varieties and bean lines using the potential identified gene source of landraces U00292, U0074, U351 and U1–9 from Uganda, genotype KKR IL05/Red 40 from Kenya and variety SER125/SER119 from Ethiopia.