Grass inflorescence morphodynamics guides yield improvement in wheat.

Grass inflorescence morphology displays remarkable diversity across species and is a key determinant of crop yield. Here, to elucidate how developmental morphodynamics shapes inflorescence architecture, we conducted a comparative analysis of early inflorescence development in bread wheat and rice. Computational modelling revealed that meristem fate transition and primordium initiation modes collectively contribute to the observed architecture diversity. Furthermore, the model elucidates the formation of distinct supernumerary spikelet types in wheat and predicts two independent developmental pathways for generating paired spikelets-a specialized form of inflorescence branching. We also identified a mutant allele, duo2, that results in accelerated developmental progression and demonstrated significant yield improvement in duo2 plants under field conditions. The causal gene RA2-D, an orthologue of maize RAMOSA2 (RA2), was found to regulate floral transition. This study elucidates how perturbations in developmental dynamics drive the diversification of grass inflorescence morphologies.