Quantitative trait loci in hop (Humulus lupulusL.) reveal complex genetic architecture underlying variation in sex, yield and cone chemistry

BMC Genomics

Research Article

Jernej Jakse¹  Branka Javornik¹  Cai-Hong Wang²  Andrzej Kilian³  Jason Carling³  René E Vaillancourt⁴  Anthony Koutoulis⁴  Erin L McAdam⁴  Jules S Freeman⁵  Simon P Whittock⁶  Andreja Cerenak⁷  Ron Beatson⁸  Dave Andersen⁸  Lawrence Graham⁸  Donna Graham⁸  Emily J Buck⁹  Peter Darby^1,10 

[1] Agronomy Department, Centre for Plant Biotechnology and Breeding, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000, Ljubljana, Slovenia;Department of Horticulture, Qingdao Agricultural University, 266109, Qingdao, China;Diversity Arrays Technology Pty Ltd, PO Box 7141, 2600ACT, Yarralumla, Australia;School of Plant Science, University of Tasmania, Private Bag 55, 7001, Hobart, TAS, Australia;School of Plant Science, University of Tasmania, Private Bag 55, 7001, Hobart, TAS, Australia;Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Locked Bag 4, 4558, Maroochydore, QLD, Australia;School of Plant Science, University of Tasmania, Private Bag 55, 7001, Hobart, TAS, Australia;Hop Products Australia, 26 Cambridge Road, 7018, Bellerive, TAS, Australia;Slovenian Institute of Hop Research and Brewing, Cesta Zalskega Tabora 2, 3310, Zalec, Slovenia;The New Zealand Institute for Plant & Food Research Limited, Old Mill Road, 7120, Motueka, New Zealand;The New Zealand Institute for Plant & Food Research Limited, Private Bag 11 600, 4442, Palmerston North, New Zealand;Wye Hops Ltd., China Farm, Upper Harbledown, CT2 9AR, Canterbury, Kent, UK;

关键词: Linkage map;    Transferable marker;    Diversity arrays technology DArT;    Pleiotropy;    Sex-linked marker;    Dry cone weight;    Plant secondary metabolite;    Hop acid;    Essential oil;   

DOI  :  10.1186/1471-2164-14-360

 received in 2013-03-13, accepted in 2013-05-23,  发布年份 2013

来源: Springer

【 摘 要 】

BackgroundHop (Humulus lupulus L.) is cultivated for its cones, the secondary metabolites of which contribute bitterness, flavour and aroma to beer. Molecular breeding methods, such as marker assisted selection (MAS), have great potential for improving the efficiency of hop breeding. The success of MAS is reliant on the identification of reliable marker-trait associations. This study used quantitative trait loci (QTL) analysis to identify marker-trait associations for hop, focusing on traits related to expediting plant sex identification, increasing yield capacity and improving bittering, flavour and aroma chemistry.ResultsQTL analysis was performed on two new linkage maps incorporating transferable Diversity Arrays Technology (DArT) markers. Sixty-three QTL were identified, influencing 36 of the 50 traits examined. A putative sex-linked marker was validated in a different pedigree, confirming the potential of this marker as a screening tool in hop breeding programs. An ontogenetically stable QTL was identified for the yield trait dry cone weight; and a QTL was identified for essential oil content, which verified the genetic basis for variation in secondary metabolite accumulation in hop cones. A total of 60 QTL were identified for 33 secondary metabolite traits. Of these, 51 were pleiotropic/linked, affecting a substantial number of secondary metabolites; nine were specific to individual secondary metabolites.ConclusionsPleiotropy and linkage, found for the first time to influence multiple hop secondary metabolites, have important implications for molecular selection methods. The selection of particular secondary metabolite profiles using pleiotropic/linked QTL will be challenging because of the difficulty of selecting for specific traits without adversely changing others. QTL specific to individual secondary metabolites, however, offer unequalled value to selection programs. In addition to their potential for selection, the QTL identified in this study advance our understanding of the genetic control of traits of current economic and breeding significance in hop and demonstrate the complex genetic architecture underlying variation in these traits. The linkage information obtained in this study, based on transferable markers, can be used to facilitate the validation of QTL, crucial to the success of MAS.

【 授权许可】

CC BY   
© McAdam et al.; licensee BioMed Central Ltd. 2013