Nora Honsdorf, Haidar Arkwazee
Hop
Hop (Humulus lupulus L.) is a perennial plant native to North America, Europe, and western
Asia. Hop is mainly cultivated for its use in beer brewing. It is a diecious plant and only female plants are cultivated to produce the cones used in the brewing process. Two types of
hop are distinguished for brewing, bittering and aroma hops.
Hop grows between the 35° and 55° latitude and main cultivation areas are located in the
northern hemisphere. The USA is the second largest producer of hops in the world. Following Washington State, Oregon is the second largest producer of hops in the US, and leading
in aroma hops production.
Hop breeding at OSU
The hop breeding program at Oregon State University focuses on aroma hop development
for the craft beer industry. With Oregon having the second largest craft brewer density in
the US, OSU is an excellent place for this breeding program. Hop varieties developed at OSU
have agronomic traits that are especially suitable for Oregon growers. In terms of agronomic traits the focus of the breeding program is on yield, resistance to downy and powdery mildews, and resistance to aphids and two-spotted spider mites. The breeding goals
for quality traits are a lower alpha acids production (bittering acids), high essential oil content, and essential oil profile. The program exists for three years now and is funded by
“Indie Hops”, an Oregon hops merchant.
In hop, new varieties are typically produced by hybrid crosses. Currently accepted varieties
are crossed with male plants with desirable traits. While only cones of the female plants are
used in brewing, male selection has to entirely rely on progeny testing. At OSU hybrid
breeding is used, but special care is taken to use pedigree records and DNA marker analysis
to design crosses between genetically distant parents. A breeding method planned to use in
future is population development. In this technique select male and female plants are allowed to randomly intercross. The resulting progeny is then tested for traits of interest, and
the selected progeny is used in a next cycle of random intercross. After two or three cycles,
individuals can be tested for release as a new variety, or be used in hybrid crosses. The idea
behind applying this new technique is to generate new genetic combinations and perhaps
break some undesired linkages.
Hop People
Shaun Townsend is the associate professor leading the aroma hops breeding program.
Temporarily, two undergraduate students and an intern support his work. The program is
closely linked to the hop research program at USDA, especially to the labs of plant
pathologist David Gent and hop breeder John Henning.
Future graduate students at Shaun´s lab will get hands on training in all parts of the breeding program. His philosophy is “Experience is the best teacher”. His goal is to educate students as future plant breeders.
Publications
Varieties released