Introgression from Triticum Turgidum Ssp. Polonicum into Durum and Bread Wheat.

Triticum turgidum ssp polonicum and ssp ispahanicum are landraces of tetraploid wheat native to Mediterranean areas and Iran. Hexaploid Triticum aestivum ssp petropavlovskyi was developed in Russia. These landraces exhibit a suite of morphological traits that may be introgressed into commercial wheats to increase photosynthesis and components of grain yield. This may contribute to doubling wheat production by 2050, even though pasta and bread making quality may require additional attention. The traits include longer and wider flag leaves, up to 4-fold larger glumes and lemmas, longer awns, up to 2 fold larger grains, additional spikelets per spike and possibly larger root biomass. The suite may increase photosynthesis in the upper regions of the plant canopy. Glume size is controlled by genes (P₁ or P₂) on chromosome 7A or 7B (Watanabe et al 2002). The other traits are controlled by several genes on different chromosomes, and are not the result of only one mutation. Presumably the suite of traits was selected by farmers in Mediterranean areas after the domestication of tetraploid wheat. We made hybrids between semidwarf California and CIMMYT durum wheats and various ssp polonicum accessions. The traits segregated normally in the F_2, BC₁ and BC₂ generations. We made crosses of ssp. polonicum with Aegilops tauschii with large grains and produced new synthetic hexaploid wheats. These were crossed and backcrossed to semidwarf bread wheats. We now have semidwarf durum and bread wheat segregants with larger flag-leaves, glumes and lemmas, awns, grains and more spikelets per spike. Promising lines will be yield tested against parental cultivars in small field plots.