Downy mildew (DM) is an important disease of cucumber and other cucurbits. Many quantitative trait loci (QTL) have been identified from different resistant resources but very few have been fine mapped or cloned. CucCAP researchers in USDA-ARS and the University of Wisconsin Madison reported identification and functional characterization of the candidate gene for the major-effect QTL, dm5.3, for DM resistance from the plant introduction line PI 197088. This gene, which can enhance plant disease signaling, is currently being used to breed for disease resistance in cucumber.
Downy mildew affects cucumber crops in South Carolina every year and can cause huge crop losses. Clemson University researchers say planting early can cut growers’ losses.
CucCAP Cucumber team members made virtual presentations at the 2022 Plant and Animal Genome meeting in January 2022.
Cucumber Team Publications and Presentations included in the 2021 Annual CucCAP Report.
The CucCAP Cucumber Team is led by Yiqun Weng. Team objectives are to develop genomic, bioinformatic, mapping approaches and tools for cucurbits, map and develop markers for disease resistance, and QTL introgression into breeding or advanced lines, and release to breeders.
Feifan Chan’s work in Yiqun Weng’s lab focuses on on pathogen resistance to downy mildew and powdery mildew in cucumber.
Researchers at Michigan State University used a fluorescent isolate of the broad host range pathogen, Phytophthora capsici, to develop a high-throughput, microtiter plate assay for replicated quantification of pathogen growth on plant tissue in real time. This method, which can detect pathogen growth prior to development of symptoms, can assist with screening for disease resistance, mapping of resistance loci, testing efficacy of control measures, or elucidation of fundamental host-pathogen interactions.
The CucCAP cucumber team is breeding cucumbers for resistance to downy mildew and Phytophthora fruit rot.