Initial Selection of Humulus lupulus L. for a Long-Term Breeding Program

Abstract

Selection of hops (Humulus lupulus L.), a dioecious perennial, in breeding programs has always been based on phenotypic evaluation of multiple genotypes. Evaluation of 239 progeny from 4 half-sibling families and 1 open-pollinated cross for powdery mildew (Podosphaera macularis) resistance, and quantification of pubescence and internode length resulted in selection of 150 progeny that will undergo further phenotypic analyses in field-grown conditions. Based upon initial results, a strong correlation (ρ = 0.52, results not shown) exists between total pubescence of the abaxial leaf surface and leaf-petiole, which may be useful in initial screening of progeny for pubescent characteristics.