Genetic loci related to kernel quality differences between a soft and a hard wheat cultivar

Hybridizations between hard and soft wheat types could be a source of novel variation for wheat quality improvement. This study was conducted to identify genomic regions related to differences in milling and baking quality between a soft and a hard cultivar of hexaploid wheat (Triticum aestivum L.). A population of 101 double-haploid lines was generated from a cross between Grandin, a hard spring wheat variety, and AC Reed, a soft spring wheat variety. The genetic map included 320 markers in 43 linkage groups and spanned 3555 cM. Quadrumat-milled flour yield, softness equivalent, flour protein content and alkaline water retention capacity were evaluated for three locations and one year, and Allis-Chalmers milling, mixograph, and cookie baking tests were completed without replication. The effect of qualitative variation for kernel texture, caused by the segregation of the Hardness gene, was controlled by regression on texture class. The residual variance was used for composite interval mapping, and QTLs on 1A, 1B, 1A/D, 2A, 2B, 2D, 3A/B, 4B, 5B and 6B were detected. The effect of some QTLs was opposite to the direction expected on the basis of parental phenotypes. The hard wheat parent contributed alleles favorable for soft wheat varieties at QTLs on 1AS,L, 1BL-2, and 6B, whereas the soft parent contributed alleles for higher protein content at QTLs on 2BL-1, 4B-1, and 6B and higher flour yield on 2BL-2 and 4B-2. These results indicated that hard X soft wheat crosses have considerable potential for improving milling and baking quality of either class.