A method of producing male-sterile wheat (Triticum) is disclosed comprising: analysing the RNA-transcriptome of wheat stamen cells and pistil cells during the development of the flower, identifying one or more male-fertility wheat (Mfw) genes that at the time of flowering are preferentially expressed in stamens rather than pistils, and inhibiting the expression of the at least one Mfw gene. Also disclosed are populations of wheat plants that are predominantly male-sterile as a result of deactivating one or more Mfw genes, processes of obtaining F1 hybrids comprising crossing male-sterile wheat plants with male-fertile wheat, and hybrids produced by these processes. Preferably, the RNA-transcriptome analysis is carried out during meiosis and between stages 41-49 of the Zadoks scale, and the wheat is T. aestivum. Preferably, the Mfw genes inhibited are Mfw1-A, Mfw1-B and/or Mfw1-D, which are homologous to Ruptured Pollen Grain 1 (RPG1, Sweet8), and/or Mfw2-A, Mfw2-B, Mfw2-D, which are homologous to Callose Synthase (CalS5, beta glucan synthase, less adherent pollen 1). The Mfw gene may be deactivated by site-directed mutagenesis using the CRISPR-Cas site-specific nuclease or by antisense RNA-interference (RNAi).
