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

The cereal cyst nematode (Heterodera filipjevi) is an invasive root pathogen causing significant economic damage of rainfed wheat fields in the Pacific Northwest states of Idaho, Oregon, and Washington. Symptoms of pathogen infection include severe yield loss, whitehead formation, and stunted root systems. There is currently no chemical control or nematicides registered in North America for the management of cereal cyst nematodes. Crop rotations of wheat with non-host crops or a long fallow is not effective long term because the eggs are protected by cysts which can survive in the soil for many years in the absence of a host. Our objective was to determine if there is already resistance in locally adapted spring wheat lines which could be introgressed into new WA varieties.  For the past two years, we have screened adapted lines in a field infested with cereal cyst nematodes near Colton, WA.  Lines were planted in two one meter rows, side by side with two rows of a susceptible check, “Alpowa”, and replicated in five blocks. Plants were harvested 45 to 60 days after planting, depending on the year, and the number of white female cysts visible on the roots was assessed. In 2012, 83 adapted lines from the Western Spring Regional Nursery were screened, and 4 lines with resistance (“UC 1711”, “SY-B041418”, “SY Steelhead” (= SY 97621-05), and “SO900163”) were identified. UC 1711 and SY Steelhead also showed resistance in our 2013 Washington State extension trial along with “AUBR31059”, “Ouyen”, “Chara”, and “WA8163” from the 84 screened lines. In addition, another seven lines showed intermediate resistance. Eight resistant lines were identified in the two locally adapted spring wheat nurseries with UC 1711 and SY Steelhead showing resistance in both 2012 and 2013.