INHERITANCE OF RUSSIAN WHEAT APHID RESISTANCE IN PI140207 SPRING WHEAT

The Russian wheat aphid (RWA), Diuraphis noxia (Mordvilko), has become a serious, perennial pest of wheat (Triticum aestivum L.) in many are as of the world. This study was initiated to determine the inheritance of RWA resistance in PI 140207 (a RWA-resistant spring wheat) and to determine its allelic relationship with a previously reported RWA resi stance gene. Crosses were made between PI 140207 and 'Pavon' (a RWA-su sceptible spring wheat). Genetic analysis was performed on the parents , F-1, F-2, backcross (BC) population and F-2-derived F-3 families. An alyses of segregation patterns of plants in the F-1, F-2, and BC popul ations, and F-2-derived F-3 families indicated single dominant gene co ntrol of RWA resistance in PI 140207. Results of the allelism test ind icated that the resistance gene in PI 140207, while conferring distinc tly different seedling reactions to RWA feeding: is the same as Dn1, t he resistance gene in PI 137739.