Carlos Roberto Carvalho, Ronaldo C. Fernandes, Guilherme Mendes Almeida Carvalho, Robert W. Barreto, Harry C. Evans

Despite the fact that coffee rust was first investigated scientifically more than a century ago, and that the disease is one of the major constraints to coffee production--constantly changing the socio-economic and historical landscape of the crop--critical aspects of the life cycle of the pathogen, Hemileia vastatrix, remain unclear. The asexual urediniospores are regarded as the only functional propagule: theoretically, making H. vastatrix a clonal species. However, the well-documented emergence of new rust pathotypes and the breakdown in genetic resistance of coffee cultivars, present a paradox.