Registration of Oilseed Sunflower Restorer Germplasms RHA 476 and RHA 477, Adapted for Short Season Environments

Abstract

Northward expansion and double crop use of sunflower (Helianthus annuus L.) is limited by the lack of commercial hybrids with early maturity. We seek to provide the sunflower industry with new, early‐maturing restorer inbred germplasms with high yield potential and favorable agronomic and seed oil traits, specifically, resistance to downy mildew, tolerance to postemergent herbicides such as the imidazolinones, and increased oleic acid in the seed oil. RHA 476 (Reg. No. GP‐344, PI 682129) and RHA 477 (Reg. No. GP‐345, PI 682130) are restorer inbred germplasms developed by pedigree selection and testcross evaluation that can fill this need. RHA 476 possesses high yield potential and high oleic acid (≥850 g kg−1) in the seed oil. RHA 477 possesses high yield potential, downy mildew resistance conditioned by PlARG, and imidazolinone herbicide tolerance. These lines were released by the USDA‐ARS, Fargo, ND, in collaboration with Agriculture and Agri‐Food Canada, Indian Head, SK, to fill the need for publicly available lines with early maturity in a high‐yielding genetic background.

Gene banks for wild and cultivated sunflower genetic resources

“…USDA has also used CWR in recent years to expand the maturity range of the breeding program. CWR resources from the primary gene pool were used to develop early maturing oilseed types for use in Canada and "double crop" systems in the central and southern U.S. (Hulke and May, 2017). Double cropping is the growing of a winter grain, which is promptly harvested, followed by a summer crop, which allows harvesting of two crops in a year.…”