Cultivation

Cultivation areas of hop crops are found in Europe, Russia, Asia, North America, Australia, and New Zealand. In 2005, 100,000 tonnes of hops were produced worldwide, a third of which was harvested in Germany alone. Hallertau in Bavaria and the Schussental between Tettang and Ravensburg in Baden-Württemberg belong to the most important cultivation areas in Germany.

Utilisation

Only the female plant of the hermaphroditic hop plant is used. The female blossoms grow in structures known as cones. They contain various bitter constituents, ethereal oils and tanning agents, as well as pharmaceutically effective substances.

Food:

"Real hop" (Humulus lupulus) is known due to its use in beer brewing.

• The dried cones of the female plant traditionally are added to the beer wort. The bitter tasting hop influences the aroma and foam-building properties of the beer.

• The bitter constituents possess an antibacterial and, therefore, conserving effect.

Pharmaceuticals:

• Some ingredients have a calming effect and are used as relaxant and sleep aid. Others are used in the prevention of cancer and for the alleviation of discomfort due to menopause.

Gene technology: aims in research and development

Agronomic traits:

The cultivation of hops is a difficult and time-consuming process. In order to simplify the process and to develop new possibilities by breeding specifically for particular traits, different bio and gene technological procedures are used, such as:

• Protoplasts: in this method, protoplasts are combined in an electrical field. Other than is the case with conventional breeding methods, the possibility to combine breeder-valuable traits without hybridisation limits exists.

• Anther culture: in this method, the plants are developed out of immature pollen (anthers, i.e. part of the male blossom in which pollen is formed) that only hold paternal hereditary dispositions. The so-obtained homozygous cultivation line allows for a pointed and simple selection and combination of desired traits that is not possible with conventional breeding.

• Genome analyses, for example in order to find resistant genes for various plant diseases.

The Bayrische Landesanstalt für Landwirtschaft (LfL) is the global leader in developing bio- and gene technological procedures in the cultivation/breeding of hops. Hops plants were successfully bred out of anther cultures (pollen). Other institutes and companies were able to regenerate hop from protoplasts. Until these procedures can assumed for practical hops breeding, further research and developmental work are necessary.

Goals for research that are aimed for with this process/method are:

Quality traits

Modified composition of ingredients

• Optimisation of characteristics in quality concerning the constructional phase.

Enrichment with health promoting ingredients such as

• boosted content of pharmaceutical effective or health promoting substances (such as xanthomuol; one of the anti-oxidants, it has a preventative effect towards cancer).

Renewable resources

Production of pharmaceutical agents

• Molecular pharming: usage of genetically modified potatoes as system for the production of medicine or vaccines; to date, only an experimental research project.

Agronomic traits

Disease resistance

• Fungal resistance to powdery mildew

Field trials with GM hops

To date no field trials with hops have been conducted. Projects with new breeding techniques are restricted to the greenhouse and the laboratory.