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ARS Home » Plains Area » Fargo, North Dakota » Edward T. Schafer Agricultural Research Center » Sunflower Improvement Research » Research » Research Project #444452

Research Project: Mapping Basal Stalk Rot Resistance and Oxalic Acid Tolerance Traits in Two Sunflower Recombinant Inbred Line Populations

Location: Sunflower Improvement Research

Project Number: 3060-21220-034-027-S
Project Type: Non-Assistance Cooperative Agreement

Start Date: Aug 1, 2023
End Date: Jul 31, 2024

The main goal of this project is to map, in parallel, genetic loci contributing to Sclerotinia basal stalk rot (BSR) resistance and oxalic acid (OA) tolerance in cultivated sunflower. The first objective for the project is to map quantitative trait loci (QTL) associated with BSR resistance using two sunflower recombinant inbred line (RIL) populations derived from the BSR resistant and OA tolerant inbred lines RHA 801 and HA 61. A second objective is to map QTL for the OA tolerance trait using these same RIL populations. Finally, we will compare validate markers associated with the resistance traits and assess correlations between BSR resistance and OA tolerance among individuals of the two populations.

To facilitate QTL mapping, DNA will be isolated from RILs from both sunflower populations and subjected to genotyping-by-sequencing to discover and genotype genetic markers. Genetic markers will be used to construct linkage maps for the two populations. To map BSR resistance, RILs from the HA 89/RHA 801 and HA 61/HA 89 crosses will be evaluated for BSR response using a greenhouse-based disease assessment. For mapping of the OA tolerance trait, RILs from both populations will be evaluated for OA response using a soil-drench assay. Genotyping and phenotyping information will be used to map QTL contributing to the traits. Correlations for BSR and OA response among individuals from each population will be evaluated to assess the potential contribution of OA tolerance to the overall level of BSR resistance.