Location: Horticultural Crops Disease and Pest Management Research Unit
Project Number: 2072-22000-046-016-R
Project Type: Reimbursable Cooperative Agreement
Start Date: Oct 1, 2020
End Date: Aug 31, 2024
Objective:
Our long-term goal is to improve and deply biologicall-based alternative eradication measures for potato cyst nematodes to replace soil fumigation. ARS scientists will participate in an objective to enhance potato breeding for resistance to potato cyst nematodes. Development of broad-spectrum resistance to G. pallida, G. rostochiensis, and G. ellingtonae. Resistance will be developed and deployed in long russet types suitable to the Pacific Northwest industry. Marker-assisted selection, and phenotyping for resistance to both G. pallida and G. ellingtonae (as a model for G. rostochiensis) will expedite breeding efforts.
Approach:
The primary market class of potato grown in Idaho and the western U.S. is characterized by varieties having long tuber shape and russet skin. Potato varieties commercially available having PCN resistance are found outside of the U.S. and typically have round tubers and white or yellow skin making them unsuitable for producers in the western U.S. Hybridizations have been conducted by the USDA-ARS at Aberdeen, Idaho between PCN-resistant breeding clones imported from Europe, New Zealand, and the International Potato Center (CIP) and PCN-susceptible russeted varieties and breeding clones. However, the resistance available for PCN is quantitative, such that multiple resistance genes provide partial resistance requiring their “pyramiding” to achieve the highest levels of PCN-resistance.
While hybrids having the desired long tuber type and russeting with moderate levels of PCN-resistance have been obtained, they have been further intercrossed to generate even higher levels of PCN-resistance via pyramiding of resistance genes. To expedite the identification and advancement of hybrids having the highest levels of PCN-resistance, marker-assisted selection (MAS) which employs molecular markers tightly linked to known PCN-resistance genes is being employed (see the following section for additional details). Those potato hybrids having suitable agronomic qualities in field evaluation as well as multiple PCN-resistance genes based on MAS analyses will then be relayed to collaborating nematologists to confirm the degree of PCN-resistance. Highly resistant clones will advance in the Aberdeen potato breeding program for the development of germplasm suitable for planting in Idaho PCN-infested acreages to aid in decreasing cyst numbers as a component of an integrated approach.
