Screening for Known Cereal Cyst Resistance Genes in Locally Adapted Spring Wheat Lines of the Pacific Northwest.

Cereal cyst nematodes (Heterodera spp.) are invasive root pathogens causing economic loss to rain-fed wheat production worldwide. The species Heterodera avenae and Heterodera filipjevi both occur in the U.S. Pacific Northwest states of Idaho, Oregon, and Washington, where the use of resistant wheat germplasm is the most cost effective and feasible method of control. Our objective was to determine the effect of Cre genes and QTLs that have been previously identified for resistance to Heterodera avenae on resistance to cereal cyst nematodes in locally adapted spring wheat breeding lines and cultivars adapted to the Pacific Northwest. Naturally infested soils, containing either predominately Heterodera filipjevi or Heterodera avenae species, were used to screen 165 wheat varieties; revealing variability in response to nematode infection. Genetic markers were applied to determine efficiency of resistance in wheat germplasm to Heterodera filipjevi, and to determine if any markers confer dual resistance to both nematode species.