Linkage between RFLP markers and genes affecting kernel hardness in wheat.

A molecular-marker linkage map of wheat (Triticum aestivum L. em. Thell) provides a powerful tool for identifying genomic regions influencing breadmaking quality. A variance analysis for kernel hardness was conducted using 114 recombinant inbred lines (F7) from a cross between a synthetic and a cultivated wheat. The major gene involved in kernel hardness, ha (hard), known to be on chromosome arm 5DS, was found to be closely linked with the locus Xmta9 corresponding to the gene of puroindoline-a. This locus explained around 63% of the phenotypic variability but there was no evidence that puroindoline-a is the product of Ha (soft). Four additional regions located on chromosomes 2A, 2D, 5B, and 6D were shown to have single-factor effects on hardness, while three others situated on chromosomes 5A, 6D and 7A had interaction effects. Positive alleles were contributed by both parents. A three-marker model explains about 75% of the variation for this trait.