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ARS Home » Pacific West Area » Wapato, Washington » Temperate Tree Fruit and Vegetable Research » Research » Research Project #444422
Research Project: Pyramiding of Potato Virus Y and Columbia Root-Knot Nematode Resistances using Greenhouse and Molecular Marker Screening

Location: Temperate Tree Fruit and Vegetable Research

Project Number: 2092-21220-003-020-T
Project Type: Trust Fund Cooperative Agreement

Start Date: May 1, 2022
End Date: Jun 30, 2025

Objective:
Develop segregating populations with combined resistances to Columbia root-knot nematode (CRKN) and Potato virus Y (PVY), and identify germplasm with combined resistance to CRKN and PVY using greenhouse and molecular marker screening.

Approach:
1. Development of segregating populations with combined resistances to CRKN and PVY Currently, all the CRKN germplasm that was developed by Tri-state breeding program are male sterile and can be used only as female parent in the hybridizations. Similarly, most of the germplasm and the varieties resistant to PVY are also male sterile except for PVY resistance from S. chacoense and some germplasm from S. andigenum. In this objective we plan on making controlled crosses with resistance to CRKN as female parent (PA99N82-4, POR15NCKY022-1) and use male fertile PVY resistant clones (Saikai 35, DG91-31, POR00LB6-1, AOR13260-3adg) as male parents. We plan on generating 4,000 to 5000 seedlings from these crosses. These populations will segregate for resistances to both CRKN and PVY. 2. Identification of germplasm with combined resistance to CRKN and PVY using greenhouse and molecular marker screening All the seedlings segregating for resistance to CRKN and PVY will be initially screened for presence of molecular markers linked to CRKN and PVY. We expect 50 % of the seedlings to be individually resistant to CRKN and PVY and at least 10 % of seedlings with resistance to both pathogens. The seedlings that have markers linked to both CRKN and PVY will be identified and will be confirmed for their resistance to both the pathogens using greenhouse screening. Screening will consist of inoculations of CRKN and mechanical inoculations with PVY. Confirmed clones with resistance to both the diseases will either be entered into the Oregon variety development program (those with agronomic merit) or will be used as parental clones for future breeding and variety development.