Identification of Leaf Rust Resistance Genes in Bread Wheat Cultivars from Ethiopia.

Wheat leaf rust, caused by (), is a widespread disease of bread wheat worldwide. In the present study, 50 wheat cultivars from Ethiopia and 34 differential lines, mostly near-isogenic lines (NILs) in the background of Thatcher with known resistance genes to leaf rust (), were tested with 14 races in the greenhouse to postulate genes at the seedling stage. Field experiments were also conducted to identify adult plant responses to leaf rust in Baoding in the 2017-2018 and 2018-2019 growing seasons and in Zhoukou in the 2018-2019 growing season. Thirteen genes (, , , , , , , , , , , , and ) either singly or in combination were found in 39 cultivars. Known genes were not present in the remaining 11 cultivars. and , each in 13 cultivars, and in 12 cultivars were the most commonly identified resistance genes. Less frequently identified genes included (five cultivars); and (each present in four cultivars); , , and (each identified in three cultivars); and (two cultivars). Evidence for the existence of , , and (each in one cultivar) was also obtained. Twenty-one cultivars were found to have slow rusting resistance to leaf rust in the field tests. The results should be valuable for cultivar selection with combinations of effective genes and used in breeding new cultivars with improved resistance to leaf rust in Ethiopia and China.