Insights into panicle trait variation and DUF-640 gene conservation in Indonesian foxtail millets (Setaria italica)

Foxtail millet (<i>Setaria italica</i>) isaresilient yet underutilised C₄cereal valued for its adaptability toabiotic stress and high nutritional content. While panicle traits have been linked toyield inmany cereals, the spatial arrangement offoxtail millet panicles remained unexplored, especially among locally adapted genotypes. This study aimed tocharacterise spatial panicle architecture traits and toanalyse the <i>DUF-640</i>, agene controlling primary branch number, among Indonesian foxtail millet genotypes. Results revealed substantial variation inpanicle architecture, including primary branch number, grain number, and grain density ineight Indonesian foxtail millet genotypes, suggesting potentially greater diversity across broader germplasm. Incontrast tothe substantial panicle trait variations, phylogenetic and structural analyses showed that <i>DUF-640</i> genes were highly conserved across <i>Setaria</i> species. Although previously associated with primary branch development, the coding sequence of<i>DUF-640</i> was not associated with branching variation inthis study. However, its high sequence conservation across <i>Setaria</i> species suggests avital and possibly conserved regulatory function. This study enhances the understanding ofthe morphological and genetic diversity offoxtail millet, particularly among Indonesian foxtail millet genotypes. Future research should focus onthe functional characterisation of<i>DUF-640</i> and the identification of regulatory sequences governing its gene expression.