Combating Rose Rosette Disease: Breeding for Resistance

In the past few decades, Rose Rosette Disease (RRD) has spread from its source in the Rockies, through the Mid-West, to the East Coast. It now threatens to decimate the US rose industry. Garden roses, which form the cornerstone of the multi-billion dollar landscape industry, annually generate wholesale US domestic bare root and container production valued at ~ $400 million. There is an urgent need to control RRD. It is caused by a novel plant virus, the Rose rosette virus (RRV), which is transmitted by windborne eriophyid mites (Phyllocoptes fructiphilus). Unlike other rose diseases it can kill a rose within two to three years of infection. The long term goal of this project is to develop roses resistant to this virus and/or mite vector. The breeding aspect of the project includes the field evaluation of 400 roses for RRD resistance. This will be done in collaboration with Mark Windham at the University of Tennessee and Tom Evans at the University of Delaware. We will work with private breeders in California, Wisconsin, Pennsylvania and Connecticut on the development of the research populations. Once developed, these populations will be propagated and planted for field assessment for RRD resistance in Tennessee and Delaware and for horticultural evaluation in Texas. The populations will be genotyped using the sequencing approach and this information will be combined with phenotype and pedigree information to identify markers associated with RRD resistance using the FlexQTL software developed by the Plant Research Institute.