The Russian wheat aphid (RWA), Diuraphis noxia (Mordvilko), is a serious economic pest of wheat worldwide. Host plant resistance is the preferred method to control RWA infestations. The identification and mapping of RWA-resistant genes and the development of resistant wheat cultivars can be facilitated through the use of molecular markers. In the present study, microsatellite markers linked to the RWA-resistant genes Dn4 and Dn6 were identified using several F2 mapping populations derived from crosses of susceptible wheat cultivars and resistant sources. Two flanking microsatellite markers Xgwm106 and Xgwm337 are linked in coupling phase with Dn4 on the short arm of wheat chromosome 1D at 7.4 cM and 12.5 cM, respectively. Two flanking microsatellite markers Xgwm44 and Xgwm111 are linked to Dn6 in coupling phase near the centromere on the short arm of chromosome 7D at 14.6 cM and 3.0 cM, respectively. This is the first report on the chromosomal location of Dn6, which proved to be either allelic or tightly linked to the previously located genes Dn1, Dn2, and Dn5. This result of Dn6 location contradicts previous reports that Dn6 was independent of Dn1, Dn2, and Dn5. The above linked markers now are used in wheat breeding programs for the accurate genotype identification of Dn4 and Dn6 genes and the selection of RWA-resistant wheats.
Species 1: Homoptera Aphididae Diuraphis noxia (Russian wheat aphid)
Species 2: Triticum aestivum (bread wheat, wheat)
Keywords: resistance, gene mapping
The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA