Abstract: Four genotypes of southern type Medicago sativa were used as experimental materials to investigate their NaCl tolerance by determing callus growth, germination rate, seedling height and radicle length under tissue culture condition. The results showed that NaCl tolerance was different among different genotypes of southern type Medicago sativa. The callus growth and germination rate were rarely affected under NaCl stress while radicle length was greatly affected under NaCl stress. When NaCl concentration was 120 mmol·L-1, the seedling growth of southern type of Medicago sativa was obviously affected. ‘Millennium’ and ‘Vitoria’ showed higher NaCl tolerance, but the NaCl tolerance of ‘Powerplant’ was the weakest. Difference in NaCl tolerance among different genotypes should be noticed when transferred southern type Medicago sativa plants were selected．

Key words: Medicago sativa, southern type, genotypes, NaCl tolerance, tissue culture