Location: Vegetable Crops Research
Project Number: 5090-21220-006-047-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Aug 1, 2026
End Date: Jul 31, 2027
Objective:
Objectives: 1. Develop a tuber assay for silver scurf and black dot suitable for germplasm screening; 2. Assess genetic diversity of pathogen isolates collected from infected potato tubers; 3. Assess fungicide resistance across a diverse pathogen isolate collection.
Approach:
Field assays for silver scurf and black dot require specific environmental conditions and are limited to one per year, significantly restricting germplasm screening throughput. We will optimize an existing protocol for medium-throughput quantitative germplasm screening to identify varying levels of silver scurf resistance. We will screen a diploid population (94 individuals) segregating for resistance, derived from a cross between resistant F5-431 and W2x112-139 parents, with resistance originating from wild species S. chacoense. Additionally, a collection of diploid wild potato species tubers will be screened for new resistance sources. Inoculated tubers will be collected, washed, and incubated to promote sporulation; spores will then be collected, concentrated, and counted for quantitative evaluation against resistant and susceptible checks.