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ARS Home » Pacific West Area » Aberdeen, Idaho » Small Grains and Potato Germplasm Research » Research » Research Project #439714

Research Project: PCN Immunity

Location: Small Grains and Potato Germplasm Research

Project Number: 2050-21000-035-037-I
Project Type: Interagency Reimbursable Agreement

Start Date: Mar 29, 2021
End Date: Sep 30, 2021

1) Conduct new hybridizations using resistant varieties obtained from breeding programs in Europe, New Zealand, and South America where Potato Cyst Nematode (PCN) has been established for many years; 2) select in the field progenies having the best agronomic types for processing and fresh industry from previously generated families; 3) individuals selected in the field will be sent to collaborating nematologists for resistance screening (phenotyping) and to a collaborating molecular biologist for assessing the presence of molecular markers associated with PCN-resistance.

Each year, hybridizations are planned and conducted at the greenhouse facilities in Aberdeen. The breeder selects PCN-resistant parents based on their resistance factor calculated against relative susceptibility of a standard susceptible (cv. Desiree). These resistant individuals are crossed with varieties/breeding clones that have the desired processing and fresh attributes. True potato seed from successful hybridizations are extracted from harvested potato fruit for planting as germinated potato seedling in the greenhouse. Seedlings will be grown in individual pots with the mature plant producing one to three seedling tubers, with the largest seedling tuber being kept and planted in the field at Aberdeen the following season as a “single hill” clone. At harvest, tubers under each single hill are dug and laid on top of the soil for visual selection for good tuber type and shape with selected individuals then being evaluated the following year in 12-hill (plant) plots. In this second year, the 12 hill selections having desirable agronomics are sent for PCN resistance phenotyping at collaborating labs in Idaho (for pallida) and Oregon (for ellingtonae). Each of these three objective components are occurring in parallel each year, so that the objectives are met by executing these methods each year. Previous research has shown that there is a high correlation between resistance response for G. ellingtonae and G. rostochiensis, so initially screenings will only involve G. pallida and G. ellingtonae. Selections with resistance to G. ellingtonae will be screened at a later date against G. rostochiensis, pathotypes Ro1 and Ro2.