Pathogen fitness penalty as a predictor of durability of disease resistance genes

Host plant resistance has been used extensively for disease control in many crop species; however, the resistance conferred by many sources is not dur able as a result of rapid changes in the pathogen. Although many resistance genes have been identified in plant germplasm, there is no easy way to pre dict the quality or durability of these resistance genes. In this review, w e revisit the hypothesis that resistance genes imposing a high penalty to t he pathogen for adaptation will likely be durable. By elucidating the molec ular changes involved in pathogen adaptation and the associated fitness cos t, a proactive approach may be developed to predict the durability of resis tance genes available for deployment.