Investigating the Effects of Salinity Stress Caused By Different Levels of Sodium Chloride (Nacl) and Potassium Chloride (Kcl) On the Growth and Quality of Sport Turfgrass

Grass is one of the most important cover plants in most green spaces, and considering that Iran is considered one of the dry and semi-arid regions of the world, water and soil salinity affects the growth of plants, as a result, using salt-resistant grass is one of the solutions to create green space in these areas. Therefore, the purpose of this research is to investigate the salinity tolerance of sport turfgrass caused by sodium chloride and potassium chloride salts.

In April, sports grass seeds were planted in an area located in Karaj province in the form of a r randomized complete block design with three replications in plots of 2 m2 (1 x 2 m2) and were cultivated with a density of 40 g m-2. The experimental treatments included sodium chloride and potassium chloride salts with concentrations of zero, 25, 50 and 75 mg l-1. After about 5 weeks of planting the seeds, salt stress was applied for one month through irrigation with salts twice a week and each time with 12 liter of salt solution and then sampling was done to evaluate fresh and dry weight of shoots and roots, total chlorophyll, proline, protein and activity of superoxide dismutase and peroxidase enzymes.

Data analysis showed that the treatments had a significant effect on the assessed traits. The highest fresh and dry weight of shoots (3.85-4.87 g) and roots (1.46-23.2 g) and total chlorophyll (16.96 mg g-1) were observed in the control, while the highest protein (3.73 μg mg-1) and activity of superoxide dismutase (4.62 enzyme units g-1) and peroxidase (4.12 enzyme units g-1) in 75 mg l-1 sodium chloride treatment and the highest proline content (12/ 8 mg g-1) was observed in 75 mg l-1 potassium chloride treatment, also the lowest fresh and dry weight of aerial parts (2.12-3.08 g) and total chlorophyll (12.53 mg g-1) in 75 mg l-1 potassium chloride treatment and the lowest fresh and dry weight of roots (0.59-0.96 g) were obtained in 75 mg l-1 sodium chloride treatment, and the lowest content of proline (4.48 mg g-1), protein (2.48 μg mg-1) and the activities of superoxide dismutase (3.00 enzyme units g-1) and peroxidase (2.93 enzyme units g-1) were in the control.

According to the obtained results, sport turfgrass was able to tolerate stress conditions in 25 and 50 mg l-1 salt stress to some extent by increasing compounds such as proline, protein and antioxidant enzyme activity, but increasing the concentration of salts used, especially potassium chloride salt (75 mg l-1) had the greatest effect in reducing the vegetative traits and increasing the enzyme activity of sport turfgrass.