Location: Emerging Pests and Pathogens Research
Project Number: 8062-22000-023-021-I
Project Type: Interagency Reimbursable Agreement
Start Date: Oct 1, 2023
End Date: Sep 30, 2025
Objective:
The goal of this project is to identify S. boliviense clones for robust PCN resistance and to generate a new mapping population for downstream mapping and cloning of novel PCN resistance gene(s). The identification of new resistant germplasm and the cloning of PCN resistance genes will help expedite PCN resistance breeding in U.S. potato cultivars, thereby offering effective tools to aid the ongoing G. pallida control and eradication efforts in Idaho.
Objectives: 1) Screen the 200 S. boliviense clones for resistance against Ro2 using pot assays. 2) Evaluate candidate S. boliviense clones for resistance against G. pallida using pot assays. And 3) Generate a mapping population derived from the resistant clone 62.3.
Approach:
Objective 1: Wild potato clones will be propagated in tissue culture and then transferred to pots. Once plants are established, they will be inoculated with Ro2 eggs using the established lab protocol. Inoculated plants will grow for three months, and nematode cysts will be extracted from the soil after plants are taken down. In the bioassay test, Desiree and Pike/Reba (susceptible cultivars) as well as Brodie (resistant cultivar) will be included as controls and a final cyst count will be used to determine the level of Ro2 resistance for each clone.
Objective 2: For the clones that are found to have Ro2 resistance, they will be evaluated for resistance against G. pallida using a similar bioassay protocol as done for Ro2. In the bioassay test, Desiree and Russet Burbank (susceptible cultivars) as well as the wild potato clone 62.3 (resistant to G. pallida) will be included as controls and a final cyst count will be used to determine the level of G. pallida resistance for each clone.
Objective 3: The resistant clone 62.3 and Yoshi6 will be grown in a greenhouse. As soon as the two plants begin to flower, genetic crosses between clone 62.3 and Yoshi6 will be conducted using a standard protocol. The fruit balls derived from the crosses will be collected when matured and progeny (true potato seeds) of the crosses will be stored in a 4°C refrigerator for further characterization when funding becomes available in subsequent years.
