Abstract

Wheat is a principal food produce in the world including Ethiopia. It gets the paramount attention of the Ethiopian government among the top 10 cereal crops to assure food security and start export. However, biotic stress especially yellow and stem rusts remained a constant production bottlenecks posing yearly economic losses of 10s of millions USD. Stem rust is being threat to wheat production due to the evolution of the virulent race of the Puccinia graminis f. sp tritici, races like Ug99 (TTKS) and its variants with rapid dispersal towards major growing areas of the country. This experiment was conducted with the aim of evaluating thirty-three advanced bread wheat genotypes and twelve commercially released varieties for both field and seedling resistance to stem rust. Treatments were grown in augmented design at field conditions and completely randomized in green house at Kulumsa agricultural research center in 2023/2024 offseason growing season respectively. Accordingly, 25(75.75%) advanced genotypes and 2(16.66%) of varieties had shown low diseases severities (FRS and ACI below 30 and 20) respectively at field conditions. However, only 11(33.33%) advanced genotypes namely; EBW170072, EBW160066, EBW170172, EBW170051, EBW160002, EBW222680, EBW170056, EBW170059, EBW170058, EBW160065 and EBW224096; and 2(16.66%) varieties Abay and Boru showed higher diseases infection type at seedling stage revealing their true slow rusting to stem rust. Therefore, the aforementioned lines can directly be exploited as resistant parental lines in the regional wheat breeding program, or suggested to be forward-looking to regional yield trials for the development of high yielding and stem rust resistant cultivars to battle with the continually changing races of stem rust and avert further wheat yield declines.