Expression pattern of Sr-genes in five bread wheat cultivars viz., HD 2135, HD 2160, HD 2189, HD 2285 and Vaishali to different stem rust pathotypes 21(9G5), 40-1(62G29-1) and 117A(36G2) and host genetic background was studied. In cvs. HD 2135, HD 2160 and HD 2285, the gene Sr30 expressed in a recessive manner to pathotype 40- 1(62G29-1), but did not express to pathotypes 21(9G5) and 117A(36G2) at temperature 19-28°C. This may be due to complex interaction between host genotype and pathotype. In Agra Local (AL) background, genes Sr5, Sr7b, Sr8a, Sr9b, SrlO and Srll expressed in a dominant manner, while Sr30 expressed in a recessive manner to above 3 pathotypes.
