Shokoufeh Sharifi - MSc. Student of agronomy, Islamic Azad University, Kermanshah Branch
Abbas Rezaei Nezhad - Scientific member of Kermanshah Research Organization
Lia Shoushtari Kermanshahi - Scientific member of Islamic Azad University, Kermanshah Branch

Iran is located on the world’s desert belt, and is considered as the arid and semiarid region. Drought is one of the major abiotic factors of environmental stresses which limits growth and distribution of natural vegetation more than that of any other factors viz. extreme temperature, cold, heavy metals, drought and salinity. Drought stress determines the success or failure of plant establishment. The adverse effects of drought on growth and development of crop plants are of multifarious nature and could affect at all the growth stages of plant growth. In order to study of drought stress tolerance of different canola (Brassica napus L.) genotypes, a field experiment was conducted on the basis of randomized complete block design with three replications under two irrigated conditions from 2012-2014 years at the Agricultural Research Station of Islamabad Gharb, Kermanshah province, Iran. Seven drought tolerance indices including Stress susceptibility index (SSI), Stress tolerance index (STI), Geometric mean productivity (GMP), Tolerance (TOL), Mean production (MP) Yield index (YP) were calculated. According to results from drought stress resistance (SSI), drought stress tolerance (TOL) at flowering stage, KS12 and at pod forming stage Karaj3 genotype was determined as superior genotypes. And according to MP, GMP and STI indices, KS7 and KR4 at flowering stage and KR4 and KS7 at pod forming stage, placed in first and second ranks by a little difference which were similar with SSI and TOL indices

drought, stress, tolerance, canola, yield