Genetic analysis and QTL mapping of a novel reduced height gene in common wheat(Triticum aestivum L.)

Low stature in wheat is closely associated with lodging resistance, and this impacts harvest index and grain yield. The discovery of novel dwarfing or semi-dwarfing genes can have great significance for dwarf wheat breeding. In this study, we identified an EMS-induced dwarf wheat mutant JE0124 from the elite cultivar Jing411. JE0124 possesses increased stem strength and a 33% reduction in plant height compared with wild type. Gibberellic acid(GA) treatment analysis suggested that JE0124 was GA-sensitive. Analysis of the frequency distribution of plant height in four F2 populations derived from crosses between JE0124 and the relatively taller varieties Nongda 5181 and WT indicated that the dwarfism phenotype was quantitatively inherited. We used two F2 populations and 312 individuals from the reciprocal cross of Nongda 5181 and JE0124 to map the quantitative trait locus(QTL) for reduced height to a 0.85-cM interval on chromosome 2 DL. The mapping was done by using a combination of 660 K SNP array-based bulked segregant analysis(BSA) and genetic linkage analysis, with logarithm of odds(LOD) scores of 5.34 and 5.78, respectively. Additionally, this QTL accounted for 8.27–8.52% of the variation in the phenotype. The dwarf mutant JE0124 and the newly discovered dwarfing gene on chromosome 2 DL in this study will enrich genetic resources for dwarf wheat breeding.