Genetic analysis and fine mapping of a dominant dwarfness gene from wild rice (Oryza barthii)

Abstract Plant architecture has been proposed as a means to enhance the potential yield of rice, especially by reducing height to provide lodging resistance. In this study, we developed a near‐isogenic line (NIL) using cultivar ‘Dianjingyou 1’ (DJY1) as a recipient parent and wild rice ( Oryza barthii ) as the donor parent. The NIL had semi‐dwarf stature and more tillers than DJY1. Cytological examination showed decreased numbers of cells in the stems of the NIL compared to DJY1. Genetic analysis indicated that this phenotype was controlled by a newly identified dominant dwarf gene, tentatively named as Dd7 . A large population derived from the hybrid NIL‐ Dd7 /DJY1 was developed to fine‐map Dd7 . Based on the physical location of molecular markers, the Dd7 locus was finally delimited to an 82‐kb region in chromosome 7. Gene prediction identified 14 open reading frames (ORFs) within this region. NIL‐ Dd7 seems to confer no undesirable pleiotropic effects and therefore has potential value for rice breeding.