Diversity in genetic and downy mildew resistance among wild and mutagenized hops as revealed by single nucleotide polymorphisms and disease rating
Wild and landrace hops growing in the Canadian Maritimes are not well studied. Previously, we collected hop samples across the Maritimes to evaluate their genetic and metabolite diversity. In this study, we aimed to enlarge the genetic base of some hop accessions and to assess the reaction of the new variants to downy mildew (DM), a destructive disease of hops.
What we did
P-Royalty (P-RL), a landrace hop collected from a protected Charlottetown municipal park, and a commercial hop cultivar (Alpharoma) were both submitted to a chemical mutagen, and the subsequent induced genetic variations were sequenced. Subsets of the untreated wild types and mutagenized hops were also inoculated with DM spores and evaluated for disease symptoms in a controlled environment.
Read this open access paper on the Canadian Journal of Plant Science website.
What we found
A large chemically-induced genetic variation was found in the treated hops alongside natural variations in the P-RL wild types. The data revealed DM tolerance in some P-RL landrace seedlings, suggesting that these wild landraces must have acquired and developed adaptation mechanisms to co-evolve with the DM disease.
Further, variations for DM resistance were observed between the mutagenized and non-mutagenized hop clones, with chemically-induced genetic variations contributing to increased DM resistance in some mutant seedlings. The authors recommend the use of true hop seeds for increased hops genetic variability in breeding programs.
Read the paper — “Diversity in genetic and downy mildew resistance among wild and mutagenized hops as revealed by single nucleotide polymorphisms and disease rating” by Mohsin Zaidi, Ashok Somalraju, Kaushik Ghose, Jason McCallum, Aaron Mills, Sherry Fillmore, and Bourlaye Fofana
