Association mapping in sunflower (Helianthus annuus L.) reveals independent control of apical vs. basal branching

BMC Plant Biology

Research Article

Daniel Ebert¹  Loren H Rieseberg¹  John E Bowers²  John M Burke²  Jennifer R Mandel³  Jonathan Corbi⁴  Savithri U Nambeesan⁵  Steven J Knapp⁶  Laura F Marek⁷ 

[1] Department of Botany, University of British Columbia, V6T 1Z4, Vancouver, BC, Canada;Department of Plant Biology, Miller Plant Sciences, University of Georgia, 30602, Athens, GA, USA;Department of Plant Biology, Miller Plant Sciences, University of Georgia, 30602, Athens, GA, USA;Present address: Department of Biological Sciences, University of Memphis, 38152, Memphis, TN, USA;Department of Plant Biology, Miller Plant Sciences, University of Georgia, 30602, Athens, GA, USA;Present address: Department of Crop and Soil Sciences, University of Georgia, 30602, Athens, GA, USA;Department of Plant Biology, Miller Plant Sciences, University of Georgia, 30602, Athens, GA, USA;Present address: Department of Horticulture, University of Georgia, 30602, Athens, GA, USA;Department of Plant Sciences, University of California, 95616, Davis, CA, USA;North Central Regional Plant Introduction Station, Iowa State University/USDA-ARS, 50014, Ames, IA, USA;

关键词: Apical dominance;    Association mapping;    Branching;    Helianthus annuus;    Linkage disequilibrium;    Plant architecture;    Sunflower;   

DOI  :  10.1186/s12870-015-0458-9

 received in 2014-10-13, accepted in 2015-02-13,  发布年份 2015

来源: Springer

【 摘 要 】

BackgroundShoot branching is an important determinant of plant architecture and influences various aspects of growth and development. Selection on branching has also played an important role in the domestication of crop plants, including sunflower (Helianthus annuus L.). Here, we describe an investigation of the genetic basis of variation in branching in sunflower via association mapping in a diverse collection of cultivated sunflower lines.ResultsDetailed phenotypic analyses revealed extensive variation in the extent and type of branching within the focal population. After correcting for population structure and kinship, association analyses were performed using a genome-wide collection of SNPs to identify genomic regions that influence a variety of branching-related traits. This work resulted in the identification of multiple previously unidentified genomic regions that contribute to variation in branching. Genomic regions that were associated with apical and mid-apical branching were generally distinct from those associated with basal and mid-basal branching. Homologs of known branching genes from other study systems (i.e., Arabidopsis, rice, pea, and petunia) were also identified from the draft assembly of the sunflower genome and their map positions were compared to those of associations identified herein. Numerous candidate branching genes were found to map in close proximity to significant branching associations.ConclusionsIn sunflower, variation in branching is genetically complex and overall branching patterns (i.e., apical vs. basal) were found to be influenced by distinct genomic regions. Moreover, numerous candidate branching genes mapped in close proximity to significant branching associations. Although the sunflower genome exhibits localized islands of elevated linkage disequilibrium (LD), these non-random associations are known to decay rapidly elsewhere. The subset of candidate genes that co-localized with significant associations in regions of low LD represents the most promising target for future functional analyses.

【 授权许可】

Unknown   
© Nambeesan et al.; licensee BioMed Central. 2015. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.