Registration of Oilseed Sunflower Germplasms RHA 485, RHA 486, and HA 487, Selected for Resistance to Phomopsis Stalk Canker and Sclerotinia, in a High-Yielding and High-Oil Background

While Sclerotinia head and basal stalk rot and downy mildew have long caused problems for the sunflower (Helianthus annuus L.) production industry, Phomopsis stem canker is a disease that is a growing issue in the United States. Our goal was to provide germplasms that contain resistance to one or more of these problematic fungi while also upholding necessary agronomic traits, including high yield and tolerance to imidazolinone herbicides. RHA 485 (Reg. no. GP-356, PI 690018) and RHA 486 (Reg. no. GP-357; PI 690019) are restorer inbred germplasms developed by pedigree method and testcross evaluation. RHA 485 has high-yield potential with high-oil content and low Phomopsis and Sclerotinia head rot incidences in the field. RHA 486 possesses high-yield potential, resistance to Phomopsis (average incidence near 0%), and low incidence of Sclerotinia basal stalk rot. HA 487 (Reg. no. GP-358, PI 690442) is a maintainer inbred line that has potential for high yield, with Sclerotinia head rot scores that are comparable to the best available checks. These lines were released by the USDA-ARS, Fargo, ND, to fill the need for germplasms with resistance to multiple diseases in addition to other important agronomic traits.