Mapping GRV resistance

Mapping Groundnut Rosette Virus (GRV) resistance for marker-assisted selection

Area of inquiry: Varietal Development

Research Focus: Malawi, Uganda

Project Length: Four years

Total Budget $299,910

Groundnut rosette disease caused by the Groundnut Rosette Virus (GRV) complex is the most destructive disease in Sub-Saharan Africa.  Resistance has been introduced into locally grown varieties and is a perfect target for genomics-assisted selection to effectively integrate resistance into future varieties. The genetic mapping resources are available for marker development, but the capacity to develop a marker tightly linked to resistance needs to be developed and implemented using the latest genomics technology and expertise. The project will develop diagnostic molecular markers that can be used to select for GRV resistance using existing RIL populations that are segregating for resistance to GRV, but not the virus vector.  We will combine strong phenotypic data with classical QTL mapping using high density SNP markers from the Affymetrix v2 array. In addition, we will carry out QTL-seq analysis using bulked tails of the phenotypic distribution. This analysis will provide population-specific markers as well as WGS for the resistant parent, ICGV-SM 90704. Markers will be evaluated in GRV hotspots in Malawi and Uganda. Additional results will be accrued from association analysis of an African diversity set that is being screened in Uganda as part of another initiative led by David Okello and Daniel Fonceka. The total effort is expected to produce strongly linked marker(s) to GRD resistance that can accessibly be deployed in breeding programs in collaboration with Intertek genotyping services. The marker(s) will be used to select efficiently for resistance so that other high value traits can be introgressed into locally adopted varieties for rapid genetic improvement.