The objective of this project is to develop new pea varieties with resistance towards root rot disease, in combination with excellent production properties. The disease is mainly caused by the oomycete Aphanomyces euteiches. Currently, neither pea varieties with resistance nor chemical pesticides are available for growers. We will cross a non-commercial pea variety (PI180693), which is partially resistant to Aphanomyces root rot, with a commercial Swedish variety (Linnea). We will utilize a new, high-throughput technique for genotyping (RAD-Seq) to identify genetic markers that co-segregate with root rot resistance in this population. These markers will then be used to speed up the plant breeding program by improving precision in the selection of resistant plants for further evaluation. Having pea varieties with resistance towards Aphanomyces root rot is a very efficient plant protection strategy, which is compatible with principles of integrated pest management and organic farming.