Genetic Loci Related to Kernel Quality Differences between a Soft and a Hard Wheat Cultivar

Abstract

processing and end-use characteristics, which depend on protein hydration and development through mixing. Hybridizations between hard and soft wheat types could be a sourceHard wheat is generally used for making bread-type of novel variation for wheat quality improvement. This study was conducted to identify genomic regions related to differences in milling and products, and soft wheat is generally preferred for baking quality between a soft and a hard cultivar of hexaploid wheat pastry-type products. Hard grain requires more energy (Triticum aestivum L.). A population of 101 double-haploid lines was to be reduced to flour than soft grain, and its starch generated from a cross between Grandin, a hard spring wheat variety, granules are damaged more during milling. Damaged and AC Reed, a soft spring wheat variety. The genetic map included starch granules absorb more water, thereby altering sev-320 markers in 43 linkage groups and spanned 3555 cM. Quadrumateral baking properties (Mok and Dick, 1991). milled flour yield, softness equivalent, flour protein content and alkaline Hybridizations between hard and soft wheat types water retention capacity were evaluated for three locations and one year, could expand the genetic base of wheat breeding and and Allis-Chalmers milling, mixograph, and cookie baking tests were create new possibilities for combinations of desirable completed without replication. The effect of qualitative variation for alleles from both germplasm subgroups. However, this kernel texture, caused by the segregation of the Hardness gene, was controlled by regression on texture class. The residual variance was used type of cross is not common practice in wheat breeding for composite interval mapping, and QTLs on 1A, 1B, 1A/D, 2A, 2B, because the two classes have distinct quality goals. 2D, 3A/B, 4B, 5B and 6B were detected. The effect of some QTLs was Carver (1996) compared interclass hybrids, backcrosses opposite to the direction expected on the basis of parental phenotypes. and progeny from a hard ϫ hard cross, and concluded The hard wheat parent contributed alleles favorable for soft wheat variethat the interclass crosses resulted in progenies with ties at QTLs on 1AS,L, 1BL-2, and 6B, whereas the soft parent contribhigher grain yield but lower flour yield and larger variuted alleles for higher protein content at QTLs on 2BL-1, 4B-1, and 6B ability for quality traits, and that recovering the quality and higher flour yield on 2BL-2 and 4B-2. These results indicated that profile of the hard type through intensive selection would hard ϫ soft wheat crosses have considerable potential for improving be feasible. Identification of quantitative trait loci (QTL) milling and baking quality of either class.related to quality differences between classes could help in planning complementary crosses and backcrosses, and in designing selection schemes to recover the quality char-

Chromosomes 3B and 4D are associated with several milling and baking quality traits in a soft white spring wheat (Triticum aestivum L.) population

“…Interestingly, these higher trait values are associated with the alleles from Penawawa, the cultivar with the lower mean values for these traits. Breseghello et al (2005) found similar QTL with effects opposite to the phenotypes. For example, the hard wheat parent in the population contributed alleles for softness, larger cookie diameter, flour yield, and sucrose retention capacity.…”

“…Flour protein quantity genes were detected on chromosome 2B. In a similar study, Breseghello et al (2005), also working with a soft by hard wheat population, detected 15 QTL on 13 linkage groups, which were putatively assigned to chromosomes 1A, 1B, 1A/D, 2A, 2B, 2D, 3A/B, 4B, 5B, and 6B. These traits were associated with milling traits, protein content, and baking assay traits.…”

Mapping quantitative trait loci (QTLs) associated with dough quality in a soft×hard bread wheat progeny

“…Other QTLs have been detected in homologous group 3. From a population of 101 doublehaploid lines generated from a cross between Grandin, a hard spring wheat variety, and AC Reed, a soft spring wheat variety, markers on 3AS that correlated with mixograph parameters were identified (Breseghello et al, 2005). …”

The determinants of grain texture in cereals

“…Additional genetic regions with genes causing small variations in kernel texture have been localized on chromosomes 1A, 1B, 1D, 2A, 2B, 2D, 3A, 3B, 3D, 4B, 5AL, 5B, 5DL, 6B, 6D and 7A (Sourdille et al 1996;Campbell et al 1999;Perretant et al 2000;Galande et al 2001;Igrejas et al 2002;Turner et al 2004;Breseghello et al 2005;Weightman et al 2008). QTLs affecting grain hardness were located on the 2A, 2D, 5B and 6D chromosomes (Sourdille et al 1996).…”