The Effects of Gamma

Radiation on Hop

By Brooke GettyMasters Student-OSU Aroma Hops Breeding

Program

Overview of Hops➢ Hop (Humulus lupulus L.)➢ Dioecious, clonally

propagated➢ Lupulin- bittering and

flavoring agent in beer

The Problem

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

Mutation Breeding

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)

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)

Goals

➢ Develop replacement hop cultivars

➢ Find markers associated with important traits in collaboration with Dr. John Henning

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

Materials and MethodsMicropropagation and irradiation of hops

Materials and MethodsGrowth, observation & transfer into sterile potting mix

Field Nursery

Previous Observations

Irradiation ResultsCascade

Field Observations

Field Observations

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

THANK YOU!➢ Dr.Townsend➢ Dr.Henning➢ Indie Hops➢ Dr. Reed➢ Dr.Shellhammer➢ Dr.Zemetra➢ German monks for

putting hops in beer!!!!!

Literature CitedSax,K.1963.The stimulation of plant growth by ionizing radiation. Radiation Botany, 3(3): 179-186.

http://mvgs.iaea.org