Thirty-six promising wheat lines, obtained from SPII, along with susceptible check were studied to assess their seedling and adult plant resistance to yellow rust. The seedling reaction was evaluated in greenhouse by using race 6E150A+,Yr27. Adult plant resistance were also evaluated by measuring of final rust severity (FRS), and coefficient of infection (CI) under natural infection conditions with two times artificial inoculation during 2010 - 2011 cropping season in field plots at Ardabil Agricultural Research Station (Iran). Artificial inoculation in field was carried out by yellow rust inoculum having virulent genes against Yr2, Yr6, Yr7, Yr9, Yr22, Yr23, Yr24, Yr25, Yr26, Yr27, YrA, and YrSU. Results showed that lines M-89-5, M-89-4 and M-88-18 along with susceptible check had the highest values of FRS and CI, therefore were selected as moderately susceptible to susceptible lines. The lines M-88-3, M-88-6, M-88-14, M- 88-16, M-89-8, M-89-10 and M-89-11 were susceptible at the seedling stage and had low level infection at adult plant stage. Consequently these lines with low level values of FRS and CI at adult plant stage most probably have durable resistance.
