Detection of Resistance Sources to Iranian Prevalent Stem Rust Races in Commercial Wheat Cultivars

In this study, reaction of 62 Iranian commercial bread wheat cultivars was evaluated for resistance to stem rust disease caused by Puccinia graminis f. sp. tritici (Pgt) at seedling and adult plant stages. Seedling tests were carried out with the prevalent stem rust races, TTSTC, TTTTF, TRTFC, TTKSK (Ug99), TTTTC and TKTTC. Adult plant reaction to stem rust was evaluated in Kelardasht research station under natural infection, and in greenhouse by artificial inoculation with race TTKSK (Ug99) at Seed and Plant Improvement Institute, Karaj. The results demonstrated that response to Pgt was significantly different among cultivars. Among 62 cultivars, 39 (63%) were identified without any effective resistance against all tested races, where 13 (21%) were resistant to one or more races but susceptible others, and 10 (16%) cultivars including, Rasool, Falat, Golestan, Atrak, Shiroodi, Dez, Zagros, Bahar, Gonbad and MV17 were susceptible to TTKSK (Ug99) and resistant to others. The latest cultivars demonstrated to carry the resistance gene Sr31.