Grain hardness in wheat is determined by the alleles at the Ha locus on 5D.

Three genes are involved, two purindolines (Pina and Pinb) and a 'grain softness protein' (Gsp-1). Please see the gene record to access the alleles noted below.

Pina-A1
Pina-A^m^1
Pina-D1 with 18 alleles.

Pinb-A1
Pinb-A^m^1
Pinb-D1 with 29 alleles.

Gsp-A1
Gsp-B1
Gsp-D1 with 10 alleles

Links to MASWheat are included for Pina-D1 and Pinb-D1 genes and alleles included in the CAPs assay.