Position Validation of the Dwarfing Gene in Oat ( L.) and Its Correlated Effects on Agronomic Traits.

An F recombinant inbred line (RIL) population derived from the cross between WAOAT2132 () and Caracas along with the two parents were used to evaluate the genetic effects of dwarfing gene on plant height and other agronomic traits in oat ( L.) across three environments, and develop closely linked markers for marker-assisted selection (MAS) for . The two parents differed in all investigated agronomic traits except for the number of whorls. The RIL lines showed a bimodal distribution for plant height in all three tested environments, supporting the height of this population was controlled by a single gene. significantly reduced plant height (37.66∼44.29%) and panicle length (13.99∼22.10%) but without compromising the coleoptile length which was often positively associated with the reduced stature caused by dwarfing genes. has also strong negative effects on hundred kernel weight (14.00∼29.55%), and kernel length (4.21∼9.47%), whereas the effects of on the kernel width were not uniform across three environments. By contrast, lines with produced more productive tillers (10.11∼10.53%) than lines without . All these together suggested the potential yield penalty associated with might be partially due to the decrease of kernel weight which is attributed largely to the reduction of kernel length. Eighty-one simple sequence repeat (SSR) primer pairs from chromosome 6D were tested, five of them were polymorphic in two parents and in two contrasting bulks, confirming the 6D location of . By using the five polymorphic markers, was mapped to an interval of 1.0 cM flanked by markers SSR83 and SSR120. Caution should be applied in using this information since maker order conflicts were observed. The close linkages of these two markers to were further validated in a range of oat lines. The newly developed markers will provide a solid basis for future efforts both in the identification of in oat germplasm and in the determination of the nature of the gene through positional cloning.