Location: Soil Management and Sugarbeet Research
Project Number: 3012-21220-011-002-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Aug 1, 2021
End Date: Feb 29, 2024
Objective:
Viral and fungal disease pressures continue to be the most pressing production challenge of sugar beet production in the United States. Host plant resistance to many of the serious disease pressures facing sugar beet production are available, but the narrow genetic basis of these resistances coupled with rapidly evolving pathogens and the loss of chemical management strategies highlight the immediate need for new genetic forms of resistance. Crop wild relatives (CWRs) have served as an important untapped reservoir for discovering new disease resistance genes for sugar beet. We aim to expand the search for resistance genes to the sugar beet CWR Beta coroliflora by developing base genomic and germplasm resources to rapidly mine this species for resistance genes to Curly Top Virus and Rhizoctonia Crown and Root Rot disease.
Approach:
To discover candidate resistance genes against Curly Top Virus and Rhizoctonia Crown and Root Rot from sugar beet crop wild relatives, the cooperator will evaluate germplasm resources from a key but underutilized wild relative of sugar beet, Beta corolliflora. Additionally, the cooperator will evaluate sugar beet monosomic addition lines which contain single copies of chromosomes from Beta corolliflora. Using controlled environment disease testing of these germplasm resources, the cooperator will identify candidate plants with resistance to these diseases. These plants will be used for genome sequencing and genetic mapping of resistance genes. Traditional genetic mapping experiments will be used in the Beta corolliflora background by crossing resistant plants with susceptible plants, followed by genotyping-by-sequencing of F2 progeny to map the genomic regions linked to resistance. A reference grade genome assembly will be created for Beta corolliflora following the identification of an individual plant showing resistance to either disease following one round of inbreeding. This reference genome sequence will be used in the genetic mapping process to identify candidate resistance genes. Candidate protein coding loci will be functionally tested using hairy root transformation in sugar beets. Direct molecular markers will be developed for candidate genes following functional validation for use in trait introgression.
