Studying the effect of two biological fertilizers on salt tolerance of tall fescue (Festuca arundinaceae schreb.)

Abstract

Biological bacteria alleviate the adverse effects of osmotic stress under salinity conditions by different processes. In the present research, factorial test was performed based on complete randomized block design and the effect of two types of bacteria azotobacter and azospirillum and five salinity levels of 0, 4, 6, 8, 12 dS/m in nutrients, fresh and dry weights of the plants, amount of auxin, proline, tillering, and quality of tall fescue were studied. Results showed that the highest dry weight of shoots, dry, and fresh weights of the roots, tillering and nitrogen have been observed in 8 dS/m salinity + azotobacter treatment. The highest fresh weight of shoot was seen in 4 dS/m salinity treatment without bacteria. The highest quality of tall fescue was seen in 4 and 6 dS/m salinity treatments without bacteria, the highest amount of sodium was seen in 12 dS/m salinity + azospirillum treatment, and the highest amount of auxin contents of roots, stems and the highest amount of phosphorus were obtained in the control + azospirillum treatment. Also, the highest amount of potassium (K) and the lowest amount of nitrogen (N) and sodium (Na) were seen in the control treatment without bacteria. The lowest amount of potassium and the lowest fresh and dry weights of the roots were seen in 12 dS/m salinity + azotobacter treatment. The lowest fresh and dry weights of the shoots were seen in 4 dS/m salinity + azospirillum treatment and 6 dS/m salinity treatment without bacteria. The lowest amount of proline was obtained in control + azotobacter treatment. The lowest amount of phosphorus and stem’s auxin and also the highest amount of proline were obtained in 12 dS/m salinity treatment without bacteria. Generally, growth-inducing bacteria reduces the adverse effects of salinity stress and improves quality of tall fescue.

Keywords:

• auxin
• azospirillum
• azotobacter
• proline
• stress
• tillering