Email: James.Milson@jic.ac.uk

Hybridisation has been shown to greatly improve crops such as maize and rice, yet despite there always being an interest in hybrid wheat production has lagged behind due to high production costs. Now with molecular advances the deployment of a system based F1 production is coming closer, this means there is now an additional focus on understanding the baking quality in hybrid wheat. Baking quality is influenced by multiple loci comprised of multiple alleles.

While effects have been well studied in inbred lines, the interaction between alleles within hybrids is not known, especially in a heterozygous state. We have tested the baking quality of 257 single-cross F1 hybrids made from 120 female and 67 male inbred parental varieties, grown over three consecutive years of field trials. From this we genotyped the parental varieties and predicted hybrid genotypes for known quality associated alleles of the Glu-1 loci which predominantly influences dough rheological traits in inbred lines.

Hybrids with homozygous alleles follow previously reported trends in the baking quality, with high-molecular weight glutenin subunit alleles influencing the largest number of measures of baking quality. Interestingly, when alleles were in a heterozygous state, we found that variations in the baking quality phenotype can depend on the parental donor with either the maternally or paternally inherited alleles having a larger effect on certain traits, i.e. the heterozygous group tends to follow the trend of the homozygous group for a parental allele.

However, some traits do not show a parental bias. We hypothesised that parental bias of heterozygous genotypes could be due to differences in the expression levels of the parental donations, as has been previously reported in other hybrid crops such as maize. We used allele-specific qPCR primers to test the relative expression of alleles donated by different parents.

We found that despite there being differences in the phenotype depending on which parent donated which allele this is not reflected in differences in the expression of the alleles, in either F1 or F2 reciprocal hybrids. This work is aiming to guide hybrid wheat breeding efforts by determining the quality traits necessary in each parental component to efficiently produce high quality hybrid wheat.