Location: Soil Management and Sugarbeet ResearchTitle: New QTL associated with Rhizoctonia solani Kühn resistance identified in two table beet x sugar beet F2:3 populations using a new table beet reference genome
|WIGG, KATHARINA - University Of Wisconsin
|BRAINARD, SCOTT - University Of Wisconsin
|GOLDMAN, IRWIN - University Of Wisconsin
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/5/2022
Publication Date: 1/19/2023
Citation: Wigg, K., Brainard, S., Metz, N.J., Dorn, K.M., Goldman, I. 2023. New QTL associated with Rhizoctonia solani Kühn resistance identified in two table beet x sugar beet F2:3 populations using a new table beet reference genome. Crop Science. 63(2):535-555. https://doi.org/10.1002/csc2.20865.
Interpretive Summary: Rhizoctonia Crown and Root Rot continues to be a major disease in many root crops, including both sugar beet and table beet. There are limited pesticides that provide season-long control of Rhizoctonia, so producers rely heavily on genetic resistance to this important disease. ARS scientists in Fort Collins, CO along with collaborators utilized modern genetic mapping experiments to discover regions of the beet genome that provide strong resistance to Rhizoctonia Crown and Root Rot. The research team identified DNA markers linked to resistance, which could be used for improving resistance to this critical disease in both sugar beet and table beet breeding programs.
Technical Abstract: The necrotrophic fungus Rhizoctonia solani Kühn is a major concern for table beet (Beta vulgaris L. ssp. vulgaris) producers across the United States causing upwards of 75% losses in severe instances. Thus far, there have been minimal efforts to incorporate host resistance to R. solani in table beet germplasm. To investigate the genetic control of R. solani resistance in table beet, we developed two mapping populations. Parents of the populations were a Rhizoctonia susceptible table beet inbred W357A x a resistant sugar beet inbred FC709-2 (Sugar Beet Resistance Population, SBRP), and a Rhizoctonia resistant table beet inbred W364B x a susceptible sugar beet inbred FC901/C817 (Table Beet Resistance Population, TBRP). In Spring 2020, F2:3 families were evaluated for response to artificial inoculation with R. solani AG 2-2 IIIB isolate R1 in replicated greenhouse experiments. This work represents the first use of the W357B table beet reference genome. Using interval mapping, we identified one quantitative trait loci (QTL) in each of the two populations, each accounting for 30% of the phenotypic variation. Both populations revealed QTL on Chromosome 2. The QTL in the SBRP contain several putative resistance genes. This is the first report of a QTL on Chromosome 2 for resistance to R. solani in B. vulgaris ssp. vulgaris and the first identification of QTL for disease resistance in table beet. Markers identified in this study may be of value for marker-assisted selection in breeding for resistance to R. solani in both sugar beet and table beet breeding programs.