Evaluation of salt tolerance of 11 approved alfalfa cultivars at seed germination stage

In order to determine the optimal concentration of salt tolerance standard and confirm the effect of different concentration of NaCl on alfalfa (Medicago sativa) seed germination, seeds of 11 approved alfalfa cultivars were germinated at different concentrations of NaCl solution. The differences of germination potential, germination rate, seedling height and root length were also compared. The results showed that there were significant differences (P0.01) on above indexes among the 11 cultivars when the seeds were treated with the 1.25% NaCl concentration; and the differences were the largest compared with other treatments. By cluster analysis of three indexes of seed germination rate, seedling height and root length of alfalfa, it could conclude that 1.25% of NaCl concentration should be the optimal concentration for determining the salt tolerance in seed germination of alfalfa. In additional, by analysis the relationship between root length and salt stress, it seemed that root growth of alfalfa could be promoted with 0.30% salt concentration treatment, but stopped with 1.00% salt concentration treatment. 1.25% salt concentration treatment inhibited root growth of alfalfa.