Abstract: In order to study the effect of melatonin on the salt resistance of tartary buckwheat, the seeds of an inbred line WTX2 of Tartary buckwheat were soaked with different concentrations of melatonin and water as control （CK）. Then the germination experiment was carried out under salt stress （100 mmol/L NaCl）. The results showed that the salt resistance of seeds treated with melatonin was significantly improved compared with CK. Seed vigor index and seedling fresh weight treated by 100 and 1 000 μmol/L melatonin were higher than those of CK. The malonaldehyde （MDA） content in seedlings treated with 100 μmol/L and 1 000 μmol/L melatonin increased slowly during germination under salt stress, while it increased sharply in CK seedlings on the 6th day of germination. The seeds treated with 100 and 1 000 μmol/L melatonin had no significant decrease in superoxide dismutase （SOD） activity during 4~6 days of germination, while the SOD activity in CK seedlings significantly decreased. There was no significant change in catalase （CAT） activity of seedlings treated with 1 000 μmol/L melatonin germinated under salt stress, while the activity of CK seedlings showed an obvious decreasing trend. Appropriate concentration of melatonin can effectively alleviate the stress of high salt on tartary buckwheat.

Key words: melatonin, tartary buckwheat, salt stress, germination, seedling growth