Breeding of triploid common hop cultivars (Humulus lupulus L.)

Abstract

Genome polyploidisation plays a special role in the progress of crop improvement in agriculture. Duplication of the entire genome is associated with significant phenotypic changes in plants, which most often lead to an increase in production at an unchanged level of input. Triploid hop genotypes are distinguished from diploids by their higher yielding potential, increased alpha-acid content and absence of seeds. For this reason, triploid hop cones are an extremely useful raw material for the brewing industry. Studies on the polyploidisation of hop genomes were initiated by Dark in 1948. In the 1950s, American researchers Neve and Farrar made an important contribution to hop triploid breeding. A significant improvement in yield per unit area and in the quality of hop raw material was brought about by the release of aromatic triploid cultivars: Willamette and Columbia to hop farmers by Haunold et al. in 1977. The development of a method for the induction of tetraploid hops using colchicine in in vitro cultures has resulted in a number of valuable high alpha as well as aromatic triploid hop cultivars being obtained in New Zealand. As a result of the breeding work carried out in Slovenia in the 1990s, an array of triploid cultivars was obtained, the introduction of which resulted in a significant increase in the cultivation area of aromatic cultivars in this country. Currently, breeding work aimed at obtaining super alpha and aromatic triploid hop cultivars is being carried out in Poland at the Institute of Soil Science and Plant Cultivation ? State Research Institute.