Male sterility systems and their applications in hybrid wheat breeding

To ensure food security for similar to 10 billion human population in 2050 a sustainable increase in food production is indispensable. Wheat is the third most consumed cereal crop worldwide after rice and maize. It is estimated that the current wheat yield will be insufficient to cope with future needs. In the past hybrid seed production has revolutionized rice and maize production; however, wheat is still lagging behind other crops, such as rice, corn, soybeans, and canola in terms of variety/hybrid development and trait development. The potential of hybrid wheat is undeniable but these challenges need to be overcome if we want to commercialize it. Despite a century of efforts we still do not have a reliable hybrid breeding system to attempt large-scale production due to certain issues like self-pollination, polyploid nature, low variability in germplasm (less than 1% cross-pollination), and higher seed rates. Moreover, a limited number of GMS genes and their regulatory pathways has narrowed our selection; further research is required to identify and understand the genetic and molecular mechanisms involved. There are few successful examples of hybrid wheat, only 1% of its total wheat growing area is hybrid wheat. There is no simple way to produce a stable wheat hybrid, until this point no one knows how to commercialize wheat on a larger scale. The use of comparative functional genomics and biotechnological tools combined with conventional breeding is likely the possible key to guarantee a stable hybrid wheat breeding and to help overcome global food security issues. This paper would provide an overview of techniques to induce male sterility in wheat and their use in commercialized hybrid seed production systems.