Preliminary results on stem rust disease in a winter wheat landrace population from Central and Western Asia
Stem rust (Puccinia graminis f. sp. tritici) is a fungal disease that can significantly reduce wheat yields and quality. The goal of this study was to screen 281 winter bread wheat landraces genotypes for their reaction to stem rust disease in seedling and adult plant stage.
For seedling stage, the experiment was carried out under greenhouse conditions in Field Crops Central Research Institute in Ankara, Turkey during 2017 growing season. The genotypes were grown at 20?4?C under greenhouse condition and inoculated (avirulent on Sr24, 26, 27, and 31 resistance genes) with urediniospores in mineral oil suspension at Zadoks growth stage 11 or 12. After inoculation, the genotypes were incubated at 20?1?C with 100% humidity during 24 hours then at 18-25?C. Scoring took place after 14 days using a 0-4 scale. Infection types on the susceptible checks (cv. Gun-91 and Thatcher) were 3+ scores. For adult plant reactions, the genotypes were screened under natural epidemic conditions for Pgt (virulent on Sr5, 6, 7b, 8a, 8b, 9b, 9g, 10, 30, Tmp and Mcn resistance genes) in Seydiler-Kastamonu, Turkey. The materials were sown in a one-meter row with three replications. Stem rust development on each entry was scored using the modified Cobb scale (Little Club had reached 80-100S) in August 2017. Coefficients of infections were calculated and values below 20 were considered to be resistant.
Two (1%) (Seedling stage) genotypes and 15 (5%) (Adult stage) genotypes were resistant to Pgt. The resistance genotypes identified in this study can be used in breeding programs. SNP markers will be identified for stem rusts resistance identified in the landrace population.