HOP (Humulus lupulus L.) Breeding Aimed at High Contents of Desmethylxanthohumol (DMX)

Three female plants (cultivars Agnus, Columbus and Admiral) and two male genotypes (99/14 and 00/6) were chosen for diallel breeding. The highest content of desmethylxanthohumol (DMX) was determined in the progenies of "Agnus x male 99/14 and 00/6", resp. However, the differences between the progenies were not statistically significant. Within combination breeding the highest content of DMX was found in genotypes originating from cultivar Vital. These progenies show higher contents of DMX than the other ones with 99% probability. In the second part of the breeding process aimed at high content of DMX we tested the hop gene pool as well as contemporary breeding material. In currently cultivated bitter hop cultivars the contents of DMX are low from 0.14 to 0.18% (Agnus, Magnum, Sládek, Dunav, Pioneer, etc.). New genotype with very high content of DMX (0.37, resp. 0.27%). In 2008 the first Czech hop cultivar (Vital) for pharmaceutical utilization was released. This variety shows high content of pharmaceutically needed compound, DMX (0.3-0.4% w/w). In comparison with other bitter cultivars of hops this content is 2-3xhigher.