ﺑﺮرﺳﻲ ﻣﻴﺰان ﭘﺮاﻛﺴﻴﺪاﺳﻴﻮن ﭼﺮﺑﻴﻬﺎ و ﻓﻌﺎﻟﻴﺖ آﻧﺰﻳﻢ ﺳﻮﭘﺮ اﻛﺴﻴﺪ دﺳﻤﻮﺗﺎز دو رﻗﻢ ﺣﺴﺎس و ﻣﺘﺤﻤﻞ ﺑﻪ ﺷﻮری ﮔﻨﺪم در ﻣﺮاﺣﻞ ﻣﺨﺘﻠﻒ رﺷﺪ در اﺛﺮ آﺑﻴﺎری ﺑﺎ آب ﺷﻮر

In order to study the effect of salt stress at different growth stage on physiological characteristics and enzyme superoxide dismutas (SOD) activity in wheat genotypes a greenhouse experiment was conducted at the Agricultural Research Green house, Agricultural, Medical and Industrial Research School, Nuclear Science and Technology Research Institute of Karaj. A split factorial design on the basis of randomized complete desing with three replications was applied. Growth stage (tillering, anthesis and 10 days after anthesis) served as main plots and a combination of five salinity treatments (0, 6, 8, 10 and 12 ds/m) and two wheat cultivars, Bam (resistance) and Tajan (susceptible to salt stress) served as subplots. Salt stress at different growth stages resulted in a decrease in relative water content. Although salinity increased MDA, content in all cultivars. The antioxidant enzyme superoxide dismutas (SOD) activity also increased under salt stress. Bam cultivar, which had higher SOD activity, had the lower MDA content than Tajan cultivar under salt stress. So the evaluation of some physiological and biochemical characteristics at the most important growth stages of wheat may be useful for screening the salinity tolerance genotypes.