Evaluation of Bread Wheat (Triticum aestivumL.) Genotypes for Stem and yellow Rust Resistance in Ethiopia
Wheat production in Ethiopia is challenged by different biotic stress. Among these biotic stresses, stem rust (Puccinia graminis f. sp. Tritici) and yellow rust (P. striiformis Westend. f. sp. Tritici) are the most devastating.. Improvement of wheat genotypes through incorporation of resistant genes to stem rust and yellow rust and testing them under hot spot areas is the most economical and environmentally friendly approach to develop resistant cultivars. Field experiment using an augmented design was undertaken at Kulumsa during 2016/17 and 2017/18 cropping season to evaluate the response of 119 elite spring bread wheat genotypes and three checks for stem and yellow rust. Based on the disease severity 71.4% and 96.6% of the genotypes showed the lowest score (0-10%) for stem rust in the first and second cropping season, respectively. About 59.7% and 66.4% of the genotypes were also showed the lowest disease severity (0-10%) for yellow rust during 2016/17 and 2017/18 cropping season, respectively. The genotypes showed significant (≤0.05) difference in Area Under Disease Progress Curve (AUDPC) for stem rust and yellow rust during 2016/17 and 2017/18 cropping season but there was significant difference (≤0.05) in Coefficient of Infection (CI) for stem rust during the first cropping season only. The genotypes exhibited significant difference (≤0.01) and (≤0.001) in CI for yellow rust in the first and second cropping season, respectively. Negative association of grain yield and thousand kernel weight with stem and yellow rust was found in both cropping season. Among the genotypes ASEEL-1//MILAN/PASTOR/3/SHAMISS-3, ZERBA6/FLAG6/3/TAM200/PASTOR//TOBA97, ZERBA-6/FLAG6/3/TAM200/PASTOR//TOBA97, NJORO SD-2/SHIHAB-12 and ICBW 206971//SHUHA-4/CHAM8/3/SIRAJ are highly resistant for both yellow and stem rust in both cropping season.