Hybrid Wheat: Current Challenges and Future Perspectives

The increasing human population and growing need for food bring about the necessity of improving crop yield capacity. In wheat, stagnating yield increase in the last decades leads to looking for new ways to achieve yield increase to meet future needs. One of the most promising options is hybrid breeding, which offers advantages over inbred lines, such as higher yield potential that harnesses the benefits of heterosis, improved yield stability, grain quality, stress tolerance, and nutrient use efficiency. Hybrid breeding has been successfully implemented in outcrossing crops and led to significant yield increases. The self-pollinating nature and closed floral characteristic of wheat make hybrid production difficult and economically not feasible due to labor-intensive implementation and low seed set. Therefore, there is a need to redesign the floral characteristics to promote outcrossing and increase the efficiency of the male sterility systems. Advances in chemical and genetic male sterility systems gave hope to plant scientists around the world to carry out hybrid wheat breeding programs. This review builds upon previous reviews and covers the floral architecture of wheat, male sterility systems, which are cytoplasmic male sterility, chemical hybridization agents, and environment-sensitive male sterility, and the status of hybrid wheat breeding.