|HILL, STEVEN - Oregon State University|
|DARBY, PETER - British Hop Association|
|HENDRIX, DAVID - Oregon State University|
Submitted to: Euphytica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/31/2016
Publication Date: 3/4/2017
Citation: Henning, J.A., Hill, S., Darby, P., Hendrix, D. 2017. QTL examination of a bi-parental mapping population segregating for “short-stature” in hop (Humulus lupulus L.). Euphytica. 213:77. doi: 10.1007/s10681-017-1848-x.
Interpretive Summary: Increasing labor costs and reduced labor pools for hop production have resulted in the necessity to develop strategies to improve efficiency and automate hop production and harvest. One solution for reducing labor inputs is the use and production of “low-trellis” hop varieties optimized for mechanical harvesting. This research looked at identifying molecular markers that can be used for germplasm and variety development of low trellis hops. Low trellis hops can be grown on low trellis (3-m tall) as opposed to normal height trellis (6-m tall). This allows for mechanical harvesting in the field as well as significantly reducing labor requirements due to the elimination of multiple labor-intensive steps required for production on normal trellis. Two molecular markers (markers 30150_18007 & 20634_10395) were identified that appear to have potential use in selecting for low-trellis hop germplasm and varieties. Other findings resulting from this research were the identification of the Y-chromosome and identification of several genes potentially involved in expression of plant height in hop.
Technical Abstract: Increasing labor costs and reduced labor pools for hop production have resulted in the necessity to develop strategies to improve efficiency and automate hop production and harvest. One solution for reducing labor inputs is the use and production of “low-trellis” hop varieties optimized for mechanical harvesting. This study was enacted to identify molecular markers that can be used to selecting short-stature hop varieties designed for low trellis production. Next generation sequencing was performed on parents and offspring of a cross segregating for low trellis growth. A new genetic map was developed with over 1530 markers covering the 10 chromosomes of hop. From this map, two molecular markers (markers 30150_18007 & 20634_10395) were located on the same chromosome mapping approximately 3.48 cM apart from each other. SNP markers were linked to DNA genome sequence and 12 genes with potential importance controlling plant growth height were identified. The molecular markers from this study will enable plant breeders to select low-trellis hop offspring from crosses in the greenhouse, thus reducing costs of field grown plants and speeding up selection.