Breeding for Hybrid Wheat: Addressing Heterosis, Hybridization and Commercial Production Practices, and Potential for Heterotic Pool Development.

Globally, wheat (Triticum aestivum L.) is one of the most important food crops. In 2013, over 70% of wheat was used directly for human consumption.  In the United States, hard red winter (HRW) wheat accounts for roughly 40% of the nation's total wheat production and is grown in the Great Plains region. Unlike other grains that have seen consistent yield gains per year over time, the rate of wheat yield increases have remained low, about 1% annually since 1959 for winter wheat in North America. To increase HRW wheat yields, many have suggested developing hybrid wheat. In order for hybrid wheat to be commercially successful, we must develop an effective hybridization system, find heterosis, and identify criteria for parent selection. In wheat, recent estimates of best parent heterosis was 10.7%. We propose that the development of hybrid wheat can benefit through the use of chemical hybridizing agents (CHAs) and genomic selection/genome wide association mapping to assist in parental selection, prediction of yield performance, and development of heterotic pools. Commercial production may be facilitated by cytoplasmic and genetic male sterility systems. In the 2014-15 growing season, a full diallel crossing block was planted at Lincoln, NE and a CHA was applied in April 2015 to induce male sterility in female plots to obtain hybrid seed. We observed differential genotypic phytotoxicity and sterility caused by the CHA, have examined genetic differences for parents from both the UNL and Texas A&M Small Grains Breeding Programs used in the diallel, and evaluated seed production and quality.