This document summarizes Brooke Getty's masters research on using gamma radiation to induce mutations in hops. The goals are to develop new hop cultivars with desirable traits and identify markers for important traits. Hops were exposed to three doses of gamma radiation (2, 3, 4 Gy) and observed for chemical profiles, survival, morphology, and disease resistance. Preliminary results found radiation affected survival and traits of Cascade hops. The research aims to develop mutation breeding as a tool for hop breeding given challenges with hop's long development time and limited genetic diversity.

1. The Effects of
Gamma
Radiation on
Hop
By Brooke Getty
Masters Student-OSU
Aroma Hops Breeding
Program

2. Overview of Hops
➢ Hop (Humulus lupulus L.)
➢ Dioecious, clonally
propagated
➢ Lupulin- bittering and
flavoring agent in beer

3. The Problem
➢ Complex chemical profile
➢ Development time ~10-14 yrs
➢ Limited germplasm
➢ Specialized equipment
➢ Long juvenility period

4. Mutation Breeding

5. Mutation Breeding
➢ Induced Mutagenesis: The use of radiation
or chemical mutagens to develop variants
with desirable traits
➢ Physical - radiation
➢ Chemical - EMS- Ethyl methanesulfonate
➢ Used since the 1930’s,
➢ Currently > 3,000 mutant cultivated varieties
(http://mvgs.iaea.org)

6. Mutation Breeding
➢ Previous literature suggested ~5.0 Gy to
induce mutation.
○ Al-Safadi,(2000)- Potatoes: 2.5 Gy (microtuber
formation)
○ Y.Lokko, H.Amoatey(1998)- Pineapple: 45 Gy (Salt
tolerance)
○ Charbaji et al., (1999)- Grape vine: 2,5,7 Gy
(Growth)

7. Goals
➢ Develop replacement hop cultivars
➢ Find markers associated with important traits
in collaboration with Dr. John Henning

8. Objectives
➢ Determine effect of 3 gamma radiation
doses(2,3,4 Gy) on Cascade and Centennial
hops.
○ Chemical and sensory profile
○ Survival
○ Morphological traits
○ Disease and insect resistance
➢ Obtain markers for important traits

9. Materials and Methods
Micropropagation and irradiation of hops

10. Materials and Methods
Growth, observation & transfer into
sterile potting mix

11. Field Nursery

12. Previous Observations

13. Irradiation Results
Cascade

14. Field Observations

15. Field Observations

16. Overview
➢ Difficult to breed replacement cultivars due
to complex chemical profile
➢ Working towards developing mutation
breeding as a potential tool
➢ Obtain markers for important traits

17. THANK YOU!
➢ Dr.Townsend
➢ Dr.Henning
➢ Indie Hops
➢ Dr. Reed
➢ Dr.Shellhammer
➢ Dr.Zemetra
➢ German monks for
putting hops in beer!!!!!

18. Literature Cited
Sax,K.1963.The stimulation of plant growth by ionizing radiation. Radiation Botany, 3(3): 179-186.
http://mvgs.iaea.org