Molecular and Milling Characteristics of Novel Puroindoline Alleles in T. aestivum.

Kammeraad, J.D., J.M. Martin, S. Cuesta, A.C. Hogg, and M.J. Giroux.  Molecular and milling characteristics of novel Puroindoline alleles in T. aestivum.  CSSA Western Section Annual Meeting, Bozeman, MT, July 8-9, 2014.

Dept. of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT 59717-3150

Molecular and milling characteristics of novel Puroindoline alleles in T. aestivum

In hexaploid wheat (T. aestivum), the Hardness (Ha) locus consists of the Puroindoline genes Pina and Pinb. Variation in Pin alleles influences grain hardness, end-product quality, and milling properties. The vast majority of current hard wheat varieties contain only 1 of 2 common Pin mutations. With a goal of improving wheat quality though an increase in Ha locus diversity, >100 novel Pin alleles were generated via EMS mutagenesis.  Pin alleles conferring defined levels of grain hardness were selected for further study to determine how functional each allele is in terms of lipid binding and its impact upon end product quality.  Six new Pinb and 3 new Pina alleles are being characterized in terms of the impact of each missense mutation upon PIN stability and starch binding.  Results indicate a positive correlation between grain hardness and the amount of starch-bound PIN protein.  Of the 9 new alleles, the majority show an increase in grain hardness, while one allele shows a decrease in hardness, possibly resulting from a gain in PIN function. In addition to PIN protein levels and grain hardness, PIN function is also closely related to seed polar lipid levels. The impacts that each new allele has on wheat end-product quality is currently being investigated, with the largest impacts expected to occur in milling properties.  These alleles will expand the range of hardness variation possible via selection for individual Pin alleles.