Specific Resistance Genes in Wheat Chinese Landrace ‘Wangshuibai’ against Two Iranian Mycosphaerella graminicola Isolates

Septoria tritici blotch, caused by the fungus Mycosphaerella graminicola, is currently the major foliar disease of wheat world-wide, and new sources of resistance and knowledge about the genetics of resistance are needed to improve breeding for resistance against this disease. An F10 recombinant inbred population from a cross between ‘Wangshuibai’ (Chinese landrace) and the susceptible cultivar ‘Seri82’ was tested at seedling stage under controlled greenhouse conditions. Two isolate-specific genes for resistance to Iranian M.graminicola isolates IPO08002 and IPO08003 were detected on Chromosomes 2BL and 7DS, respectively. For both genes the resistance was derived from ‘Wangshuibai’ at positions where Stb9 (on 2BL) and Stb4 (on 7DS) have been reported previously. These two genes are closely linked to microsatellite markers, which can be used for marker-assisted selection. ‘Wangshuibai’ may therefore be a valuable source of resistance to STB for wheat breeding, especially in Mediterranean environments.