The allelic relationships among Russian wheat aphid resistance genes in two Iranian wheat lines and known genes

The availability of more resistance genes to Russian wheat aphid (RWA), Diuraphis noxia (Mordvilko) may provide additional protection from new virulent strains or biotypes of the insect. This genetic study was conducted to determine the allelic relationships of resistance genes in two Iranian wheat (Triticum aestivum L.) lines, SHZ.W.102 and SHZ.W.104 and lines PI 137739, PI 262660, PI 372129, PI 294994 and PI 243781, carrying resistance genes Dn1, Dn2, Dn4, Dn5 and Dn6 respectively. The two Iranian lines were crossed to each of the other resistant lines, and F1 and F2 seedlings were screened for RWA reaction. The resistance gene in 102 was allelic to Dn1, however, the resistance gene in 104 was different from other known genes. The resistant line 104 is an effective source of genetic resistance to RWA and the gene symbol Dn7 is proposed for its resistance gene.