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ARS Home » Pacific West Area » Corvallis, Oregon » Forage Seed and Cereal Research Unit » Research » Publications at this Location » Publication #221698
Title: AFLP Discrimination of Wild American and Cultivated Hop

Author
item TOWNSEND, M - OREGON STATE UNIVERSITY
item Henning, John

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/31/2009
Publication Date: 3/31/2009
Citation: Townsend, M.S., Henning, J.A. 2009. AFLP Discrimination of Wild American and Cultivated Hop. Crop Science. 49:600-607.

Interpretive Summary: Hop breeding traditionally utilized simple selection techniques such as clonal selection or simple “pick-the-winner” selection within established breeding lines. Most of these breeding lines are related and resulting crosses tend towards exhibiting inbreeding depression in resulting offspring. Relying on a narrow genetic base to address production problems may lead to a genetic bottleneck in breeding germplasm, and may limit a breeder's ability to select for new traits. The objective of this research was to assess the genetic relationship of Humulus lupulus var. lupuloides and H. l. var. pubescens accessions with domesticated hop germplasm currently utilized by the USDA-ARS hop breeding program. A total of 59 hop accessions representing both domesticated (N=20) and wild-type Humulus (N=39) were evaluated using molecular markers. Statistical analyses showed the wild American accessions were genetically distinct from the domesticated germplasm. Within the wild-type Humulus two distinct groups were observed representing the two different sub-species. In addition, two distinct groups were observed in the cultivated hop accessions: European derived hop germplasm and European x wild type hybrid germplasm. Results from this research suggest incorporating wild type hop accessions into the USDA-ARS hop breeding program to enhance the genetic diversity of this valuable germplasm resource.

Technical Abstract: Hop breeding historically relied upon relatively simple selection techniques within established breeding lines. Relying on a narrow genetic base to address production problems may lead to a genetic bottleneck in breeding germplasm, and may limit a breeder's ability to select for new traits. The objective of this research was to assess the genetic relationship of Humulus lupulus var. lupuloides and H. l. var. pubescens accessions with domesticated hop germplasm currently utilized by the USDA-ARS hop breeding program. A total of 59 hop accessions representing both domesticated (N=20) and wild-type Humulus (N=39) were evaluated using AFLP molecular markers. Principal components analysis and hierarchal cluster analysis showed the wild American accessions clustering separately from the domesticated germplasm. Within each of the two main groups, two smaller subgroups were evident. Results from this research suggest genetically incorporating wild American hop accessions to enhance the genetic diversity within the USDA-ARS hop breeding program.