Exploiting the Genetic Diversity of Aegilops tauschii to Improve the Yield and Adaptation of Winter Wheat.

Cultivated bread wheat (Triticum aestivum L.) is characterized by relatively low genetic diversity, which limits future genetic gains. One strategy for improving wheat’s genetic diversity is to incorporate synthetic hexaploid germplasm, formed from the hybridization of the diploid wild ancestor Aegilops tauschii and tetraploid durum wheat (Triticum durum). We crossed six synthetic hexaploid lines to the Colorado wheat cultivar Hatcher, backcrossed once or twice to Hatcher, and evaluated the resulting progeny lines in field trials under a variety of soil moisture conditions from 2010 to 2016. Our results indicated that some lines were equal to Hatcher in yield and test weight, but none consistently outperformed the cultivar. Examination of yield components and disease resistance indicated that some lines possessed larger seed size, an increased number of seeds per square meter, or improved levels of resistance to stripe rust (Puccinia striiformis Westend) compared to the recurrent parent. Some of the evaluated lines may be useful for improving the performance and diversity of U.S. Great Plains germplasm.