QTL Cloning: Colorado State University

stephen pearce

Co-PI: Stephen Pearce

scott haley

Co-PI: Scott Haley

andrew katz

PhD student: Andrew Katz

Andrew will be working to characterize a QTL for spikelet number on chromosome arm 6BL (503Mb) identified from a GWAS on the Hard Winter Wheat Association Mapping Panel. This QTL was validated in an F5:6 Platte/CO940610 RIL population (n=224) during the 2016-2017 field season. The 6BL QTL Platte allele showed a positive effect of 0.39 spikelets per spike (R2=11.8, P < 0.0001).  The RIL population is also segregating for three alleles with known effects on spikelet number; VRN-D3a/b, PPD-B1a/b, and a 7AL QTL under investigation at UC Davis.

For the 2018-2019 field season, the F5:7 Platte/CO940610 RIL population (n=218) was planted to validate the effect of the 6BL QTL on spikelet number. Eight F5:6 heterogeneous inbred families (n=96 individuals per family) derived from the F4:5 Platte/Co940610 RIL population were planted to screen for critical recombinants for fine-scale mapping and to test the interactions between the 6BL QTL and the known spikelet number alleles. To introgress the 6BL QTL into elite materials, we have generated F1 seed from crosses between Platte (carrying the favorable 6BL and 7AL alleles) and three high-biomass CIMMYT lines (Bonsu, Nadi, and Mucuy) and commenced crosses with two Colorado advanced breeding lines (Monarch and CO13D1479) that carry the 6BL allele for low spikelet number.