Effects of Na2CO3 stress on the germination of Festuca arundinacea seeds

The effects of different concentrations of Na2CO3 (0,20,40,60,80,100 mmol·L-1) on seed germination of four cultivarsof tall fescue (Festuca arundinacea) were studied.The results showed that salt stress delayed tall fescue initial germination and the germination peak,and slowed down the germination process.With the Na2CO3 concentration increase,the germination rate and germination potential of the four cultivars of tall fescue seed declined.The relationship between the relative germination rate of four cultivars and salt concentration was hyperbola correlation.Equation of linear regression were: y=-6E-05x2-1.203 5x+110.61 (Jaguar 3),y=0.007 4x2-1.792 8x+101.58(Athena),y=-0.001x2-1.070 3x+107.72 (Arid 3),y=0.004 9x2-1.728x+114.97 (Phoenix).The salt tolerance critical value of four cultivars of tall fescue were 87.2 mmol·L-1 (Jaguar 3),73.2 mmol·L-1(Athena),84.6 mmol·L-1(Arid 3),78.4 mmol·L-1(Phoenix),respectively.Jaguar 3 exhibited greater germination ability under salt stress,then followed by Arid 3 and Phoenix,and the salt tolerance of Athena was the worst.