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ARS Home » Midwest Area » St. Paul, Minnesota » Plant Science Research » Research » Publications at this Location » Publication #331155
Title: Genetic architecture of flowering time variation in Brachypodium distachyon

Author
item WOODS, DANIEL - University Of Wisconsin
item BEDNARK, RYLAND - University Of Wisconsin
item BOUCHE, FREDERIC - University Of Wisconsin
item GORDON, SEAN - Department Of Energy
item VOGEL, JOHN - Department Of Energy
item Garvin, David
item AMASINO, RICHARD - University Of Wisconsin

Submitted to: Plant Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/22/2016
Publication Date: 1/1/2017
Citation: Woods, D., Bednark, R., Bouche, F., Gordon, S., Vogel, J., Garvin, D.F., Amasino, R. 2017. Genetic architecture of flowering time variation in Brachypodium distachyon. Plant Physiology. 173:269-279. doi:https://doi.org/10.1104/pp.16.01178.

Interpretive Summary: The timing of flowering is an important trait in crops, because if it occurs too early or too late significant yield losses may occur due to either cold or hot temperatures damaging flowers. Thus much research has sought to understand the genes that regulate flowering time. While a number of genes in the flowering time pathway have been identified in crops such as wheat, the picture that they paint is incomplete. To identify additional genes involved in the regulation of flowering time, a genetic analysis of flowering time variation present in two genotypes of Brachypodium distachyon, a small wild grass that is related to wheat, was conducted. The results obtained identified two genes that are the same as major flowering time genes that are known in wheat, and at least one other that has been characterized in the model dicot Arabidopsis. However, two additional regions of the Brachypodium genome were identified that contain one or more genes that also play a role in regulating flowering time, but they do not contain any genes previously associated with flowering time. Advancing our understanding of the genetic basis of flowering time in grasses will permit the precise development of wheat and other cool season cereal crops that flower at optimal times depending on where they are grown. This will provide greater yield stability, increased producer profits, and enhanced food security.

Technical Abstract: The transition to reproductive development is a crucial step of a plant’s life cycle, and the timing of this transition is an important factor in crop yields. Here, we report new insights into the genetic control of natural variation in flowering time in Brachypodium distachyon, a non-domesticated cool season pooid grass closely related to wheat and barley. A recombinant inbred line (RIL) population derived from a cross between the rapid flowering accession Bd21 and the winter habit accession Bd1-1 was grown in a variety of environmental conditions to determine the genetic architecture of flowering time. We utilized a genotyping-by-sequencing (GBS) approach to develop SNP markers to develop a genetic map for quantitative trait loci (QTL) mapping. We identified a small number of QTL that control differences in flowering time. Many of the flowering time QTL are detected across various environmental conditions, suggesting that the genetic control of flowering within this population is robust across a range of photoperiod and vernalization conditions. The two major QTLs identified colocalize with VERNALIZATION1 and VERNALIZATION2, genes identified as flowering regulators in wheat and barley. This suggests that variation in flowering time is controlled in part by a conserved set of genes broadly within pooid grasses.