Abstract: [Objective] The aim of this study was to assess the effects of exogenous ascorbic acid （AsA） priming on seed vigor of forage triticale under Na₂SO₄ stress. [Method] The seed germination test of forage triticale was carried out under the stress of Na₂SO₄ solution at the concentration of 75 mmol/L after the treatment of 0 （CK）, 4, 8, 16, and 24 h with AsA solution at the concentrations of 0.5, 1.0, 1.5, and 2.0 mmol/L. Subsequently, the changes of germination percentage （Gp）, germination index （Gi）, seedlings vigor index （SVI）, and mean germination time （MGT） of the seeds were analyzed. [Result] The effects of AsA concentration on Gp, Gi and SVI of forage triticale seeds were highly significant （P<0.01）, and the effects on MGT were not significant （P>0.05）. The effects of AsA priming time on Gp, Gi, MGT and SVI of forage triticale seeds was highly significant （P<0.01）. The interaction between AsA concentration and priming time was highly significant （P<0.01） for Gp and SVI and non-significant （P>0.05） for Gi and MGT of forage triticale seeds. The AsA concentration of 1.5 mmol/L triggered for 8 h resulted in the highest Gp, Gi and SVI as well as the shortest MGT in forage triticale seeds. When AsA concentration was 2.0 mmol/L for 24 h, Gp, Gi and SVI of forage triticale seeds were lower than other priming times, while MGT was longer than other priming times. [Conclusion] The effects of exogenous AsA priming on seed vigor of forage triticale under Na₂SO₄ stress were closely related to its concentration, priming time and the interaction between the two. AsA at a concentration of 1.5 mmol/L for 8 h possessed the best effect on the seed vigor of forage triticale under 75 mmol/L Na₂SO₄ stress.

Key words: forage triticale, Na₂SO₄ stress, ascorbic acid, seed priming, seed vigor