Manipulation of male fertility in a polyploid species requires attention to the interaction of male-fertility alleles of multiple genomes. In hexaploid wheat, single-genome heterozygotes for Ms26 provide differential levels of male fertility across genomes. Hexaploid wheat homozygous for mutations in the Ms26 gene on the A, B, and D genomes is male-sterile. Male fertility may be restored by sufficient levels of expression of Ms26 using native Ms26 or a transgene, which may be native to wheat or to another species, or a combination of native and transgenic alleles. CRISPR/Cas9 technology may be used to generate mutations in Ms26 in wheat or rice.
