Genetics and Resistance Mechanism of the Cucumber (Cucumis sativus L.) Against Powdery Mildew

Abstract

Powdery mildew (PM) is one of the most severe foliar diseases in cucumbers (Cucumis sativus L.), but the inheritance of PM resistance remains unclear. The molecular mechanisms underlying PM resistance have been a bottle-neck in the advancement of cucumber cultivars. However, recent findings have provided valuable information on the molecular mechanisms of defense-related genes and signaling pathways. Moreover, several PM resistance genes have been cloned, and their functions have been verified in cucumbers. In this review, we will focus on the inheritance and molecular mechanisms of PM resistance in cucumbers and generalize the known PM resistance genes and signaling pathways. These novel discoveries have advanced the molecular understanding of PM resistance and provide a foundation for the further breeding of resistant cucumber varieties.