The ability of plants to identify an optimal flowering time is critical for ensuring the production of viable seeds. The main environmental factors that influence the flowering time include the ambient temperature and day length. In wheat, the ability to assess the day length is controlled by photoperiod (Ppd) genes. Due to its allohexaploid nature, bread wheat carries the following three Ppd-1 genes: Ppd-A1, Ppd-B1 and Ppd-D1. While photoperiod (in)sensitivity controlled by Ppd-A1 and Ppd-D1 is mainly determined by sequence changes in the promoter region, the impact of the Ppd-B1 alleles on the heading time has been linked to changes in the copy numbers (and possibly their methylation status) and sequence changes in the promoter region. Here, we report that plants with the same number of Ppd-B1 copies may have different heading times. Differences were observed among F7 lines derived from crossing two spring hexaploid wheat varieties. Several lines carrying three copies of Ppd-B1 headed 16 days later than other plants in the population with the same number of gene copies. This effect was associated with changes in the gene expression level and methylation of the Ppd-B1 gene.

Crop Research Institute Drnovská 507 Prague Czech Republic

Czech University of Life Sciences Prague Kamýcká 129 Prague 6 Czech Republic

Institute of Experimental Botany Centre of the Region Haná for Biotechnological and Agricultural Research Šlechtitelů 31 CZ Olomouc Czech Republic

PLoS One. 2018 Feb 12;13(2):e0192989. doi: 10.1371/journal.pone.0192989. PubMed

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Wild emmer wheat, the progenitor of modern bread wheat, exhibits great diversity in the VERNALIZATION1 gene

In-Depth Sequence Analysis of Bread Wheat VRN1 Genes