A survey of the genetic diversity and disease resistance status in the Canadian Maritime wild hops




Alpha and beta acids confer flavor, aroma, bitterness and medicinal properties to beer, and are extracted from female hops flowers (cones) in the brewing process. During brewing, alpha acids are converted into iso-alpha acids, which impart bitterness and anti-microbial properties to beer, whereas beta acids are more often linked with health-promotion, including anti-cancer activities. Currently, most commercial hops varieties can be traced back to a common ancestry, mostly arising in Europe, highlighting their narrow genetic background and, most are susceptible to common fungal diseases such as downy mildew. In this study, we assembled a collection of wild-growing hops from the Maritimes region of Canada, and created EMS-mutant derivatives for enlarging the genetic background of 2 wild types and a commercial variety. This collection was characterized for genetic diversity by targeting 7 key biosynthetic genes (Humulone synthases, HS1 and HS2; Prenyltransferases, HIPT1L and HIPT2; valerophenone synthase, VPS; and the branched-chain aminotransferases, BCAT1 and BACT2) involved directly or indirectly in alpha and beta acids biosynthesis in hops cones. Furthermore, a subset of the collection was assessed for disease resistance to downy mildew. The extent of genetic diversity in the collection as well as variations in disease resistance will be reported and discussed.