Abstract
In the process of disease protection, we encounter numerous problems such as breakdown of disease resistance cultivar and emergence of fungicide tolerant pathogen. For the success of durable disease protection, we have to study the infection strategies and lifecycles of pathogen, and prepare multiple disease protection measures. Most of the disease resistance (R) genes function as a receptor for pathogen. However, most of the R genes sense dispensable factor for life or pathogenicity. Once the dispensable factors mutate, the disease resistance cultivars carrying R genes fail to sense pathogen, causing the breakdown of disease resistance. If an R gene senses essential factor for life or pathogenicity, that is Achilles' heel of the pathogen, it would be a durable R gene. I present a possibility to create novel R gene by directed evolution.
