Evaluation of polymorphisms among South African winter wheat varieties

Wheat production globally is constrained by among other factors stem rust. Stem rust is a major disease of wheat that can result in up to 100% yield losses. Though stem rust had been managed before using host resistance genes, most of these genes have been overcome by emergence of new and virulent stem rust races such as Ug99. The stem rust race Ug99 is virulent against most commonly used stem rust resistance genes and currently about 8595% of wheat varieties are reported to be susceptible. At present, 13 variants of Ug99 that differ in virulence been reported in 13 countries. In South Africa, a number of winter varieties have been shown to possess resistance against some stem rust race. However, the genes conferring resistance in these varieties are not known. Therefore, new sources of resistance should be explored and deployed in commercial varieties. The objective of this study was to screen for polymorphisms among different parental lines. Eight stem rust resistant winter wheat varieties and a single susceptible spring wheat variety were screened for polymorphisms with 42 SSR markers. Results show presence of variation among parental lines hence suitable for mapping of stem rust resistance.