Screening of CIMMYT Wheat Genotypes to Stem Rust Disease under Field Conditions in Egypt غربلة التراکیب الوراثیة لقمح السیمیت ضد مرض صدأ الساق تحت ظروف الحقل فی مصر

Abstract

Among 190 wheat genotypes (CIMMYT), 51 lines were evaluated for adult plant resistance (APR) to stem rust infection at Sakha, Kafr El-Hamam and Nubaria locations, as the new sources of this resistance. Extensive and high significant differences of stem rust reaction among the tested wheat lines were obtained, at the three locations under study. Out of 51 wheat genotypes, only eight promising lines; no's 1, 9, 12, 14, 20, 25, 47 and 49 had the highest resistant potentiality at adult stage (completely resistant) and utilized as the new sources to increase stem rust resistance. Twenty nine wheat lines were characterized as partially resistant (PR), at the three locations of the study. The phenotypic variations were attributable to genetic structures of the lines due to high heritability estimates (up to 99%) and high values of genetic advance. The importance of all the selected disease parameters was confirmed through the correlation analysis especially final rust severity (FRS %). It is considered to be the more appropriate indicator, rather than area under disease progress curve (AUDPC) and relative area under disease progress curve (rAUDPC) for screening large numbers of breeding materials to stem rust resistance and facilitate the success of selection process, during a national breeding program.