Transfer of Soft Kernel Texture from Triticum aestivum to Durum Wheat, Triticum turgidum ssp. durum

Durum wheat (Triticum turgidum ssp. durum) is a leading cereal grain whose primary use is the production of semolina and pasta. Its rich culinary relationship to humans is related, in part, to its very hard kernel texture. This very hard texture is due to the loss of the Puroindoline genes that were eliminated during the allopolyploid formation of T. turgidum approximately 0.5 million years ago. In the present report, we describe the transfer of the Puroindoline genes through ph1b-mediated homoeologous recombination. Puroindoline a and Puroindoline b were successfully recombined (translocated) from chromosome 5D of the soft wheat (T. aestivum) variety Chinese Spring into cv. Langdon durum using a Langdon 5D(5B) disomic substitution line. Although initial recombination lines were highly unstable, recurrent backcrossing into Svevo durum cultivar produced stable lines that segregated in a normal 1:2:1 soft: heterozygous: very hard ratio. The final backcross (BC3) Svevo line produced uniformly soft grain (Single Kernel Characterization System hardness of 24 +/- 14). The transfer of this fundamental grain property to durum wheat will undoubtedly have an expansive and profound effect on the way that durum grain is milled and on the products that are made from it. As such, our interaction with this important food species will continue to evolve.