Assessment of the genetic diversity of wild hops (Humulus lupulus L.) in Europe using chemical and molecular analyses

The goal of this study was to characterize European wild hops (Humulus lupulus L.) by chemical and molecular genetic analyses in comparison to cultivated hops and North American wild hops. The contents of alpha and beta and acids varied from 0.45% to 5.55% and from 1.22% to 5.73% in European wild hops, respectively. Low bitter acid contents, alpha/beta acid ratios of lower than 1.0 and cohumulone content not exceeding 30% were typical as well as for traditional European cultivars. The lower myrcene content, the presence of farnesene and high selinene content were typical for European wild hops. We evaluated molecular genetic diversity in European wild hops by microsatellite and gene-specific markers and found that this variability did not correlate with the chemical characteristics. Our phylogenetic analysis confirmed overlapping variability and close genetic relationships in Europe, the separation of wild hops from the Caucasus region and the high diversity of North American wild hops.