Journal of Crop Breeding

     Salt stress is one of the most important environmental constrains that limited agricultural productivity. Salinity stress is also one of the most important obstacles worldwide that production of tolerant cultivars may reduce its problems. In present study, from five promising alfalfa lines, elite genotypes were selected and individually transplanted into isolated polycross nursery for improving a synthetic SSI variety. Five alfalfa promising lines, together with SSI and SM synthetic varieties and a local check cultivar were assessed for salt tolerance in salty (soil and water) conditions during 2010 to 2013. Results showed significant differences between varieties and years (P£0.01), however, cutting and interaction effects were non-significant. SM synthetic variety produced the most yields; however, the lowest yield was belonged to the local check cultivar. Height and yield of promising verities were non-significant comparing with local check cultivar while was significant for synthetic varieties. The mean yields of synthetic varieties and promising varieties were 1682.3 and 757.7 gr.plant^-1, respectively, although their height differences were non-significant. Results of orthogonal comparison showed that the synthetic varieties absolutely were better than promising alfalfa verities and local check cultivar. Also, the SM synthetic variety yielded much better than the SSI synthetic variety.