Salt effects on germination and seedling growth of sainfoin (Onobrychis viciifolia Scop.) genotypes

Sainfoin (Onobrychis viciifolia Scop.) is widely grown as forage and pasture legume in Iran and is tolerant to environmental stresses. Developing cultivars with higher salt tolerance at germination stage will increase seedling establishment and yield. This experiment was conducted to determine the effects of different concentrations of sodium chloride (0، 0. 1، 0. 2، 0. 3 M) on the germination، seedling growth، Na and K uptake of ten Iranian sainfoin genotypes. Results indicated that salt has significant effects on all parameters and the threshold for germination was determined as 0. 2 Molar. Increasing the salt concentration decreased germination percentage، rate of germination، seedling viability percentage، root length، shoot length، root and shoot dry weight، percentage of Na uptake and K/Na ratio. In contrast shoot length/root length ratio and percentage of K uptake was significantly increased. The sainfoin genotypes showed considerable variation for salt tolerance based on the measured characters at germination stage and a variety selected from Khonsar population (KH304A) was found the most tolerant one. Cluster analysis based on all of the recorded characters, classified the genotypes in three clusters that mainly supported germination parameters of entries. Results indicated that there is sufficient genetic variation for salt tolerance among the studied genotypes and they can be used to improve salt tolerance of sainfoin in breeding programs.