Characterization and Selection of Hop Cultivars Adapted to Nebraska

Authors

Kristina Alas, University of Nebraska-LincolnFollow

First Advisor

Keenan Amundsen

Second Advisor

Donald J. Lee

Date of this Version

Summer 7-18-2022

Citation

Alas, K. (2022). Characterization and Selection of Hop Cultivars Adapted to Nebraska. Theses, Dissertations, and Student Research in Agronomy and Horticulture.

Comments

A THESIS Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Master of Science, Major: Agronomy, Under the Supervision of Professors Keenan Amundsen and Donald J. Lee. Lincoln, Nebraska: August, 2022

Copyright @ 2022 Kristina Alas

Abstract

Hop (Humulus lupulus L.) is an ingredient in the beer brewing industry that provides beer its flavor and aroma. High demand from the brewing industry has encouraged production outside of the traditional Pacific Northwest, the primary production region. Producers in the Midwest are attempting to grow cultivars adapted to the Pacific Northwest, but environmental differences have caused low yields and changes in secondary metabolite content. To aid producers, a regional breeding program was initiated to develop cultivars adapted to the Midwest. Success of any breeding program relies on the selection of genetically superior parents to generate progeny with the traits of interest and genetically superior progeny for potential release. Therefore, objectives of this study included identifying superior parents, breeding populations, and progeny that could be used as foundational germplasm in a newly created hop breeding project. Traits characterized included performance ratings, flowering time, alpha acid content, and cohumulone content. Performance ratings and flowering time were evaluated annually from 2019 to 2021, and alpha acid content and cohumulone content were evaluated in 2020 and 2021. Data for this study were unbalanced, number of progeny from each parent and breeding population varied. Progeny genotypes changed from year to year, and number of replicates of individual genotypes also varied. Breeding values of both parents and populations varied widely for the traits measured, indicating that parents were diverse and that improved cultivars can be developed from germplasm used in this study. Sixteen maternal parents, 18 paternal parents, and 23 breeding populations were selected as superior and advanced for use in future progeny development. Genetic values (BLUPs) of the progeny were variable for all traits evaluated. Forty-nine female progeny were selected as superior and will be advanced with potential for release as locally adapted cultivars. Information gained from this study will support future breeding decisions contributing to the development of new Midwest adapted hop cultivars.

Advisors: Keenan Amundsen and Donald J. Lee