Microsatellite mapping of a Russian wheat aphid resistance gene on chromosome 7B of an Iranian tetraploid wheat line: preliminary results

Russian wheat aphid (Diuraphis noxia Mordvilko) is a cosmopolitan pest of wheat. Development of resistant genetic sources is economically and environmentally effective. The objective of this study was to localize and tag a Russian wheat aphid resistance gene in Iranian tetraploid wheat line '1881', using microsatellite markers. Thirty pairs of microsatellite primers of group 7 chromosomes of wheat were screened, using bulked-segregant analysis. Four microsatellite primer pairs of chromosome 7B revealed polymorphism between susceptible and resistant parents and bulk DNA samples of resistant and susceptible individuals, among which the linkage of 2 markers was confirmed. The locus Xgwm46-7B was the closest to the RWA resistance locus with a distance of 10 cM. The identified locus on chromosome 7B of the tetraploid wheat line '1881' may be orthologous to one of the previously identified RWA resistance loci on chromosome 7D.