TaCKX6-D1, the ortholog of rice OsCKX2, is associated with grain weight in hexaploid wheat
Article first published online: 6 JUN 2012
© 2012 Institute of Crop Sciences. CAAS New Phytologist © 2012 New Phytologist Trust
Volume 195, Issue 3, pages 574–584, August 2012
How to Cite
Zhang, L., Zhao, Y.-L., Gao, L.-F., Zhao, G.-Y., Zhou, R.-H., Zhang, B.-S. and Jia, J.-Z. (2012), TaCKX6-D1, the ortholog of rice OsCKX2, is associated with grain weight in hexaploid wheat. New Phytologist, 195: 574–584. doi: 10.1111/j.1469-8137.2012.04194.x
- Issue published online: 9 JUL 2012
- Article first published online: 6 JUN 2012
- Received: 22 March 2012, Accepted: 23 April 2012
- cytokinin oxidase/dehydrogenase;
- grain weight;
- •The cytokinin oxidase/dehydrogenase (CKX) gene plays a principal role in controlling cytokinin levels and has been shown to be a major quantitative trait locus (QTL) affecting grain number in rice. However, the function and evaluation of the haplotypes of the wheat CKX gene have yet to be illustrated.
- •In this study, TaCKX6-D1, a wheat ortholog of rice OsCKX2, was cloned and its haplotype variants were determined to be significantly associated with the 1000-grain weight on the basis of linkage mapping, association analysis and gene expression analysis.
- •Five TaCKX6-D1 haplotypes, designated a–e, were identified. An indel marker was developed to identify haplotype a, which was associated with higher grain weight. Haplotype a showed decreased expression relative to haplotype b in seeds at 8 d after pollination. Sequence variations among modern cultivars, landraces and wild species suggest a significant domestication signature at the TaCKX6-D1 locus in Chinese wheat germplasm.
- •TaCKX6-D1 may serve as a useful gene for the breeding of high-yielding wheat. A strategy for allele mining and utilization of TaCKX6-D1 was proposed. Our study also sheds light on the mechanisms of grain development and domestication of wheat, as well as the functional divergence of orthologs in comparative genomics.