Abstract: [Objective] The aim of the present study was to assess the effects of exogenous ascorbic acid （AsA） priming on seed vigor of forage triticale （× Triticosecale Wittmack）under NaCl stress. [Method] Forage triticale 'Jisi No.3' seeds were primed in AsA solutions at the concentrations of 0.5, 1.0, 1.5 and 2.0 mmol/L for 0 （CK）, 4, 8, 16 and 24 h, respectively, and were then germinated under NaCl stress at a concentration of 100 mmol/L. The germination percentage （Gp）, germination index （Gi）, mean germination time （MGT） and seedlings vigor index （SVI） of the seeds were determined and statistically compared. [Result] The priming concentration or duration of the exogenous AsA had extremely significant （P<0.01） effects on Gp, Gi, MGT and SVI of the forage triticale seeds. In addition, the mutual combination effect of both reached significant （P<0.05） level on SVI and extremely significant （P<0.01） level on Gp,Gi and MGT. The highest values of Gp, Gi and SVI as well as the lowest value of MGT were observed in the seeds with AsA priming for 4 h at a concentration of 1.0 mmol/L. In the AsA priming concentration range of 0.5-2.0 mmol/L, the seeds had lower Gp, Gi and SVI as well as higher MGT when they were primed for 24 h in comparison to those at the other priming times. [Conclusion] The effects of AsA priming on seed vigor of forage triticale under NaCl stress were closely related to the priming concentration and duration as well as their synergistic action. Priming with AsA at a concentration of 1.0 mmol/L for 4 h exhibited the most effective improvement in seed vigor of forage triticale under a salt stress environment of 100 mmol/L NaCl.

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