Evaluation of resistance to wheat stem rust and identification of resistance genes in wheat lines from Heilongjiang province.

Wheat stem rust, caused by f. sp. , () is a devastating disease in wheat production. The disease has been effectively controlled since the 1970s due to the widespread use of the resistance gene However, has lost its effectiveness following the emergence and spread of the Ug99 race variants. Therefore, there is an urgent global effort to identify new germplasm resources effective against those races. In this study, the resistance to of 95 wheat advance lines from Heilongjiang Province was evaluated using three predominant races of , 21C3CTTTM, 34C0MKGSM, and 34C3MTGQM, in China at the seedling and adult plant stage. The presence of 6 genes (, , , , , and ) was evaluated using linked molecular markers. The results showed that 86 (90.5%) wheat lines had plant stage resistance to all three races. Molecular marker analysis showed that 24 wheat lines likely carried , 15 wheat lines likely carried , 11 wheat lines likely carried , while none of the wheat lines carried , , or . Furthermore, six out of the 95 wheat lines tested carried both and , three contained both and , and two wheat lines contained both and . Wheat lines with known genes may be used as donor parents for further breeding programs to provide resistance to stem rust.