Technology applied to the development of new flavour hop varieties in Australia

Hop production in Australia occupies a total of approximately 500 hectares, spread across two major farms and several smaller growers. Production is based in south-eastern Australia, spread roughly evenly between Victoria and Tasmania, latitudes 37-41° south respectively. Every hop grower in Australia relies upon varieties developed locally since 1950, in a breeding program, which continues today. Since 1994, collaborative work (predominantly with the University of Tasmania - UTAS) has seen the development of technologies such as in vitro colchicine induction to produce tetraploid plants, and flow cytometry, which have led lately to the availability of tetraploid male and female plants, and the ability to conduct tetraploid by tetraploid crosses. An extensive database of gas chromatography-mass spectrometry (GC-MS) of steam distilled hop essential oil profiles has been built up, containing information on international varieties, Australian commercial varieties, and selected material. Australian hop researchers have participated actively in the international collaboration to develop Diversity Arrays Technology (DArT) markers. Future work will include quantitative genetic analysis of large progeny trials grown in both Tasmania and Victoria, the establishment of a linkage mapping population replicated in both Tasmania and Victoria, and application and further development of DArT markers in specific roles with the new cultivar development process. Active collaboration provides hop breeding efforts in Australia with the tools necessary to create, identify, and develop novel varieties with diverse and exciting flavour potential.