Morphological and Genetic Analysis of Wild Hop (Humulus lupulus L.) Germplasm from Calabria Region in South Italy

Hops (Humulus lupulus L.) constitute a species that grows spontaneously in the region of Calabria (South Italy), but the species' morphological and genetic characterization have not yet been explored. Thus, we explored some morphological traits related to cones of wild hops from three Calabrian sites: Cosenza (CS), Catanzaro (CZ), and Vibo Valentia (VV). In addition, eight Simple Sequence Repeats (SSR) were adopted to investigate the genetic diversity and population structure of the local germplasm, which were also compared to commercial varieties. Cone length exhibited large variation among the different populations, whereas cone shape was the most discriminant trait according to principal coordinate analysis. Eighty-one alleles were detected with a high mean of alleles per locus (10.12). The SSRs used in the present study were highly informative with a genetic diversity of 0.829 and a PIC value > 0.62, thereby confirming the high genetic variability in Calabria. Finally, genetic structure analysis revealed the existence of two distinct groups regardless of the specimens' sampling sites. Further studies including other wild hops populations from Calabria will be performed in order to detect specific alleles for new breeding programs.