ffect of Salinity on Germination and Threshold Salinity in Barley

To study the effect of salinity on germination and threshold of barley germplasms two experiments carried out as a factorial arrangement based on completely randomized designin greenhouse and laboratory condition. In the first experiment 23 barley germplasms (17 wild and 6 improved barely cultivars) were investigated for germination index with four treatments of salinity (0، 100، 200 and 300 Mm NaCl) in three replications and in the second experiment the threshold salinity of 7 germplasms that selected from the first experiment were analyzed in five treatments (1. 3، 5، 10، 15 and 20 ds. m-1) with four replications. At the end of the first experiment،following factors were measured: germination percent،root length،shoot length،root fresh weight،root dry weight،shoot fresh weight،shoot dry weight،Na+ root content،K+ root content،Na+ shoot content،K+shoot content also threshold salinity، shoot length، dry and fresh weight، Na+and K+content was measured in the second experiment. The result showed that increased salt concentrations caused decrease final germination percentage (P≤0. 05). Some of germplasms showed high tolerance to salinity. The relative yield of dry weight indicated that H. vulgare،var. Afzal with 25. 24 ds. m-1andH. murinum (Ilam) with 16. 65 ds. m-1 which had the maximum and minimum EC50 value respectively between these germplasms. In this experiment the native cultivar had a highest tolerance with compared to the other cultivars that is likely contain genes for resistance to salt stress.