Towards the replacement of wheat 'Green Revolution' genes

Abstract

First introduced into wheat breeding programs in the 1930s, the Rht-B1b and Rht-D1b 'Green Revolution' alleles remain the most widely used dwarfing genes in today's wheat varieties. Wheat plants with shorter stems channel a greater proportion of their resources into developing grains, although these alleles also reduce coleoptile length, limiting their utility in dry environments where seeds must be sown deeply. In this issue, Tang et al. (2021) show in a series of comprehensive field trials that an alternative dwarfing allele, Rht18, confers a reduction in height nearly identical to Rht-D1b, but has no impact on coleoptile length. These findings highlight the promise of replacing dwarfing alleles as a strategy to optimize wheat height according to the target environment.