Phenotypic effect and chromosomal localization of Ddw3, the dominant dwarfing gene in rye (Secale cereale L.)

Abstract Dwarfing genes play a major role in development of semi-dwarf cultivars of various cereals, but in rye this type of cultivar is still not common. Several recessive and dominant dwarfing genes in rye have been reported. Among the known dominant dwarfing genes in rye, two are well characterised: Ddw1 from the 5RL chromosome and Ddw2 located on 7R. This study was aimed at characterisation of the K11 source of dominantly inherited dwarfism found in plant materials grown in the Plant Breeding and Acclimatization Institute (Radzików, Poland). Mapping analyses in this study indicate that the dominant dwarf gene under investigation is located on the 1RL chromosome and is independent from previously known genes. The gene was named Ddw3 . Phenotypic effect of the Ddw3 was tested on two pairs of near-isogenic lines. Six morphological traits were analysed in two or three growing seasons: plant height, length of the second internode from the base, number of internodes, tillering, spike length, and number of spikelets per spike. No negative or weak influences on yield-related traits were observed. The examination of the dwarf plants’ reaction to seedling treatment by gibberellic acid solution revealed sensitivity of Ddw3 to this growth regulator. This report is the first evidence of the dominant Ddw3 gene in rye and its presence on the 1R chromosome.