Common bean is an economically, nutritionally, and socially important crop. It is grown in distinct regions and different seasons around the world by subsistence level farmers with low-technology input as well as by farmers that use high input technologies. One important factor that can limit the bean growing and drastically affect grain yields is the high number of destructive pathogens that attack and cause serious damage to the crop. Among them is bean rust, incited by the fungus Uromyces appendiculatus. This disease is distributed throughout the world, but it effectively causes major production problems in humid tropical and subtropical regions. In Brazil, rust causes major losses in south, southeast, and central regions of the country. Bean rust control by resistant cultivars is an easy and economical strategy to be used in association to other rust management practices. Pyramiding of different race-specific resistance genes in association with other genes conferring adult plant resistance, slow rusting, and reduced pustule size can prolong the lifespan of a common bean cultivar by creating a more durable resistance complex against the rust pathogen. This review manuscript presents an overview on bean rust and reports some breeding efforts aiming to develop rust resistant cultivars in Brazil.

A ferrugem do feijoeiro comum (Phaseolus vulgaris), incitada pelo fungo Uromyces appendiculatus, é uma das mais importantes doenças que afetam essa cultura. Trabalhos anteriores demonstraram a ampla variabilidade patogênica de U. appendiculatus no Brasil. No entanto, o uso de distintos grupos de cultivares diferenciadoras em tais trabalhos dificulta a análise comparativa e a identificação de fontes de resistência de amplo espectro. Assim, os objetivos deste trabalho foram: 1) caracterizar sete isolados de U. appendiculatus, coletados em diferentes regiões do estado de Minas Gerais, frente às 19 cultivares diferenciadoras para ferrugem, adotadas no "The Bean Rust Workshop", realizado em 1983, em Porto Rico, e 2) comparar os padrões de resistência/suscetibilidade obtidos, com aqueles apresentados frente a patótipos isolados nos estados de Santa Catarina, Rio Grande do Sul e Goiás, visando identificar fontes de resistência de amplo espectro. Os sete isolados coletados em Minas Gerais foram classificados com sete patótipos distintos. As cultivares diferenciadoras com os maiores espectros de resistência foram 'Redlands Pioneer', 'California Small White 643', 'Brown Beauty', 'AxS 37' e 'Compuesto Negro Chimaltenango'. Portanto, apesar da exclusão das cultivares California Small White 643, AxS 37 e Brown Beauty da nova série diferenciadora internacional proposta em 2002, na África do Sul, recomenda-se adicionar estas cultivares nas futuras caracterizações de patótipos a serem realizadas no Brasil, como um modo de monitorar a variabilidade patogênica de populações de U. appendiculatus nas regiões produtoras.

Common bean (Phaseolus vulgaris) rust, incited by Uromyces appendiculatus, is among the most important diseases affecting this culture. Several works have demonstrated the extensive pathogenic variability of U. appendiculatus in Brazil. However, the use of distinct sets of differential cultivars prevents the comparison among the data obtained and the identification of sources with ample resistance spectra. The objectives of this work were: 1) to characterize seven U. appendiculatus isolates collected in different regions of the state of Minas Gerais in relation to the 19 rust differential cultivars defined in the "The Bean Rust Workshop" in 1983, in Porto Rico, and 2) to compare the resistance/susceptibility patterns obtained with those reported with isolates collected in Santa Catarina, Rio Grande do Sul and Goiás, to identify sources with ample resistance spectra. The seven isolates collected in the state of Minas Gerais were classified as seven different pathotypes. The differential cultivars with the largest resistance spectra were 'Redlands Pioneer', 'California Small White 643', 'Brown Beauty', 'AxS 37' and 'Compuesto Negro Chimaltenango'. Despite the fact that the cultivars California Small White 643, AxS 37 and Brown Beauty have been excluded from the new differential series proposed in 2002, in South Africa, we strongly recommend that these three cultivars should also be characterized in future studies in Brazil as a mean of monitoring the pathogenic variability of U. apppendiculatus populations in bean growing regions.