Breeding of flavour hops in the Czech Republic

Hop breeding in the Czech Republic develops a number of flavour hops. The Kazbek hop variety was registered in 2008 and the Mimosa variety in 2019. The best 7 hop genotypes were selected from breeding materials between the years 2014 and 2019. Kazbek, 5512 (Ceres) and 5571 (Eris) expressed a clear citrusy flavour. Mimosa, 5495 (Juno) and 5520 (Saturn) could be described as fruity while 5164 (Uran), 5540 (Jupiter) and 5580 (Pluto) as rather spicy. Genotype 5164 showed the highest aroma intensity, content of alpha acids (11.51% w/w) and alpha/beta ratio (2.20). Whereas Mimosa demonstrated the highest content of beta acids (5.56% w/w) and the lowest alpha/beta ratio (0.28), 5571 and 5520 had the highest cohumulone amount (49.19% rel. and 47.35% rel., respectively). In contrast, 5580 were distinguished by the lowest cohumulone (21.28% rel.). The highest amount of hop oils was determined in 5164 (1.77 w/w) and 5520 (1.53 w/w). 5164, 5540 and 5495 showed a myrcene level above 40% rel. On the other hand, Kazbek, Mimosa and 5571 indicated a myrcene content below 35%. The highest level of farnesene (12.50% rel.) was detected in 5164; in other samples the values were below 1% rel. Mimosa showed the highest concentration of selinenes (32.75% rel.); other samples demonstrated selinenes below 10% rel. The Kazbek variety is the foundation for the breeding of flavour hops in the Czech Republic, and therefore it is the mother plant of genotypes 5495, 5512, 5520, 5540 and 5571. Harmonie is the mother plant of genotype 5580.