Mapping QTL for Agronomic Traits on Wheat Chromosome 3A and a Comparison of Recombinant Inbred Chromosome Line Populations

Variation for wheat (Triticum aestivum L.) grain yield and agronomic traits was used to map quantitative trait loci (QTL) in a 'Cheyenne' (CNN) x [CNN ('Wichita' 3A)] recombinant inbred chromosome line (RICL) population consisting of 223 CNN(RICLs3A) and 7 check cultivars that were evaluated in six environments in Nebraska during 2005-2007. A chromosome 3A linkage map spanning 106 cM was constructed using 32 microsatellite markers. Composite interval mapping detected 19 QTL for seven agronomic traits that individually accounted for 4.6 to 16.8% of the phenotypic variation. Three small genomic segments, spanning 3.4, 5.3, and 5.3 cM, contained most of the QTL. Two yield QTL were detected in two environments and in data pooled over environments. For grain volume weight, a QTL was detected in five of the six environments while a plant height QTL was detected in all environments. Wichita (WI) alleles contributed to the increased trait values for yield, spikes per square meter, and grain volume weight, while CNN contributed alleles to the increased 1000-kernel weight, plant height, and anthesis date. Both CNN and WI contained alleles for increased number of kernels per spike. The 223 CNN(RICLs3A) set had greater power to detect QTL than the two smaller subsets-128 CNN(RICLs3A) developed using doubled haploids and 95 CNN(RICLs3A) developed using recombinant monosomic lines. Neither of the subsets performed consistently better than the other in detecting QTL.