Registration of Seven Spring Two-Rowed Barley Germplasm Lines Resistant to Russian Wheat Aphid

230 Journal of Plant Registrations, Vol 2, No. 3, September 2008 Devastating yield losses occurred in wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) in the western United States within 2 yr after the fi rst appearance of the Russian wheat aphid [RWA; Diuraphis noxia, (Mordvilko)] in 1986 (Porter et al., 1999). Screening of the entire USDA-ARS National Small Grains Collection of H. vulgare in the greenhouse by the USDA-ARS in Stillwater, OK, resulted in the identifi cation of 109 accessions with resistance to RWA ranging from resistant (1–3) to moderately resistant (4–5) on Webster’s scale of 1 to 9 (1 = resistant, 9 = susceptible) (Webster et al., 1991) From these heterogeneous accessions, 109 homogeneous unadapted RWA-resistant germplasm lines were developed by selecting for RWA resistance as well as plant type. Two spring Registration of Seven Spring Two-Rowed Barley Germplasm Lines Resistant to Russian Wheat Aphid