Hop variety classification using the genetic distance based on RAPD

Fifty-one hop varieties from around the world were subjected to random amplified polymorphic DNA (RAPD) analysis with 10-mer arbitrary primers. Polymorphism was scored and the genetic distance was calculated as the proportion of shared DNA bands in a pair of varieties for the construction of a dendogram by an unweighted pair-group method was arithmetical averages. The varieties were roughly classified into 6 clusters, and the similarity between varieties correlated with their breeding history. The result also suggests that at least two populations existed in ancient times and the hops cultivated in England originated front or are related to both populations. Many high alpha varieties have a genetic composition unlike old European hops. This difference is thought to result from the integration of wild American hops.