Registration of Downy Mildew–Resistant Male Hop Germplasm USDA 21087M

Abstract

USDA 21087M (Reg. No. GP‐36, PI 558607) male hop ( Humulus lupulus L. var. lupulus ) germplasm was released to the public on 6 Dec. 2011. This germplasm has been used by the USDA–ARS for hop cultivar development for several decades. Nonagency interest in this germplasm was expressed, and release of this material is considered beneficial for the US public. USDA 21087M was obtained from the former Yugoslavia by the USDA–ARS in 1974 as Selection 3/3. The defining characteristics of USDA 21087M are its high resistance to downy mildew in the US Pacific Northwest, potential resistance to non‐v4/v6 strains of powdery mildew, and potential good storage ability in hop offspring. It is expected that hop breeders will use this germplasm as a parent for development of downy mildew–resistant hop cultivars. The release of USDA 21087M will give both public and private breeders new germplasm for cultivar and germplasm development.