Meiotic instability and irregular chromosome pairing underpin heat‐induced infertility in bread wheat carrying the Rht‐B1b or Rht‐D1b Green Revolution genes

• DOI: 10.1111/nph.19256
• Publication Date: 2023-09-11T05:30:48Z
• Authors: András Cseh; Andrea Lenykó‐Thegze; Diána Makai; Fanni Szabados; Kamirán Áron Hamow; Zsolt Gulyás; Tibor Kiss; Ildikó Karsai; Blanka Moncsek; Edit Mihók; Adél Sepsi
• Keywords: 2. Zero hunger; S1 Agriculture (General) / mezőgazdaság általában; Plant Breeding; Hot Temperature; Infertility; Bread; 630; Triticum; Alleles; Chromosomes

Summary Mutations in the Rht‐B1a and Rht‐D1a genes of wheat ( Triticum aestivum ; resulting Rht‐B1b Rht‐D1b alleles) cause gibberellin‐insensitive dwarfism are one most important elements increased yield introduced during ‘Green Revolution’. We measured effects a short period heat imposed early reproductive stage on near‐isogenic lines carrying or alleles, with respect to wild‐type (WT). The temperature shift caused significant fertility loss within ears wheats, greater than that observed for WT. Defects chromosome synapsis, reduced homologous recombination high frequency mis‐segregation were associated fertility. transcription TaGA3ox gene involved final gibberellic acid (GA) biosynthesis was activated ultra‐performance liquid chromatography–tandem mass spectrometry identified GA 1 as dominant bioactive developing ears, but levels unaffected by elevated temperature. mutants inclined meiotic errors under optimal temperatures showed higher susceptibility their tall counterparts. Identification introduction new dwarfing alleles into modern breeding programmes is invaluable development climate‐resilient varieties.