QTL Cloning: University of Idaho

jianli chen

Co-PI: Jianli Chen

daolin fu

Co-PI: Daolin Fu

rui wang

Postdoctoral Fellow: Rui Wang

Our project will validate, clone, and deploy a QTL for spikelet number per spike (SPS) located on long arm of chromosome 5A (143.6~176.3 cM, at least 37 cM away from Vrn-A1 locus). This QTL, designated as Q.SPS.UI-5A, was identified in a bi-parental mapping study using 115 DH lines derived from two high yield cultivars (UI Platinum and SY Capstone). The population was assessed for SPS in five trials of two years and was genotyped by high-density Illumina 90K single nucleotide polymorphisms (SNPs) assay.


The QTL showed LOD at 13 and explained 41% phenotypic variation. On average, lines carrying the UI Platinum allele have 1.3 more spikelets per spike than those carrying the SY Capstone allele.

Based on 600 F4 lines derived from the same cross, we have already identified 26 F4 lines that are heterozygous for three tightly linked SNP marker (170 cM to 176.3 cM) in the QTL region. The F4:2 plants segregating for the target region will be evaluated in greenhouse and field in 2017.

On the other hand, to deploy this SPS gene, crosses will be made between UI Platinum and some other valuable cultivars or breeding lines in 2017 summer.