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JPSS Jülich Plant Science Seminar Series:

15.07.2015 13:00 Uhr
15.07.2015 14:00 Uhr
Forschungszentrum Jülich, Gebäude 06.2 IBG-2, Seminarraum 406, 2.Stock

Modelling the genetic architecture of flowering time control in barley through nested association

Flowering time is a major agronomic trait determining yield potential and yield stability of crop plants.

We developed the first barley nested association mapping (NAM) population, HEB-25, derived from crossing 25 wild barley donors with one elite barley recipient, and used it to dissect the genetic architecture of flowering time. Upon cultivation of 1,420 HEB lines in multi-field trials and applying a genome-wide association study, eight major quantitative trait loci (QTL) were identified to control flowering time. Together, they accounted for a cross-validated explained proportion of genotypic variance (pG) of 64%.

The QTL were located with high genetic precision, where all except one QTL interval included known genes controlling flowering time. The strongest single QTL effect corresponded to the photoperiod response gene Ppd-H1, explaining a pG of 36%. After sequencing the causative part of Ppd-H1, we differentiated twelve haplotypes in HEB-25. The strongest exotic haplotype at Ppd-H1 accelerated flowering time by 11.1 days compared to the elite barley haplotype.

Applying a genomic prediction model including main effects and epistatic interactions between QTL allowed to further extend the cross-validated explained pG to an extraordinary high level of 77%. Our findings represent a first step to elaborate a causal model explaining flowering time control in barley.

We conclude that HEB-25 is a valuable novel genetic tool, allowing to dissect the genetic architecture of important agronomic traits and to expand the genetic diversity of our elite barley gene pool with favorable exotic alleles.

Contact: Fabio FioraniUli Schurr, Tobias Wojciechowski