Effects of NaCl stress on two blue fescue varieties (Festuca glauca)

Abstract

Blue fescue is a widely used ornamental grass worldwide. Research on its salt resistance is propitious to its application in northern China where there are large areas of saline-alkali land. This study was conducted to examine the effects of NaCl stress on two blue fescue varieties Valesiaca and Select. Percentage of green leaves (PGL) of both Valesiaca and Select responded similarly to 0.3% and 0.6% NaCl treatments. Under a higher NaCl application level (1.2% NaCl), Valesiaca was reduced by below 60% at the 12th day and reached 20% at the end of the experiment, but Select to 71.67% at the 12th day and stayed over 50% unto the end. The 0.9% and 1.2% NaCl treatments sharply increased Proline content, and then reached and maintained at a maximum level throughout the treatment. Proline content of Valesiaca increased to 2.28 mmol·L−1 at the 8th day after the 1.2% NaCl treatment, but only 0.95 mmol·L−1 in the treatment of 0.3% at the same day. For Valesiaca, 1.2% NaCl treatment significantly increased its SOD activity to 30.69 units·mg−1, nearly 50% higher than 0.3% treatment at the 8th day after treatment, and over 53% higher at the 27th day. POD activity of Valesiaca increased to 6.92 units·mg−1 at the 8th day after the 1.2% NaCl treatment, but it was 2.59 units·mg−1 for 0.3% stress treatment. In conclusion, similar changes of determined index were observed for both cultivars under low NaCl stress levels (0.3%–0.6%). However, Valesiaca was more sensitive and less tolerant to high level NaCl stress (0.9%–1.2%) than Select, indicating that Valesiaca was less resistant to NaCl compared with Select.