Location: Genetic Improvement for Fruits & Vegetables Laboratory
Project Number: 8042-21000-305-027-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Sep 1, 2025
End Date: Aug 31, 2026
Objective:
Identify diploid potato breeding clones that have resistance to common scab (Streptomyces sp.) and/or tolerance to heat stress. Calculate breeding values and conduct a genome-wide association study to determine regions of the diploid potato genome associated with common scab and heat resistance.
Approach:
At USDA-ARS and Michigan State University, diploid potato breeding is a focus of ongoing research efforts. This is part of a national effort to develop uniform true potato seed, which can replace seed tubers at the early stages of commercial seed tuber production. Michigan State University's potato breeding program maintains a common scab nursery with high levels of Streptomyces and is routinely used for determining potato clone resistance levels to common scab. Seed tubers from the ARS diploid breeding clones will be planted in the scab nursery at the Montcalm Research Farm (Stanton, Michigan). At harvest, tubers will be scored based on the percentage and severity of scab symptoms. Scab screening data will be analyzed to identify scab resistant diploid potato breeding clones which demonstrated resistance to common scab. Clones evaluated for scab resistance will be genotyped on the Illumina SNP array V4. The scab resistance data will be analyzed together with the genotype data to calculate genomic prediction models and breeding values for common scab resistance.