Biochemical and physiological adjustments in common bermudagrass (Cynodon dactylon [L.] Pers.) and tall fescue (Festuca arundinacea Schreb.) under low temperature stress

Low temperature is a restrictive factor for turfgrass growth and development in temperate regions. A study was conducted with the purpose of examining the physiological and antioxidant response of two turf species, Festuca arundinacea Schreb. ‘Starlett’ and Cynodon dactylon [L.] Pers. ‘California Origin’ to cold stress in a growth chamber at the College of Agriculture, Shiraz University. Five temperatures (25, 15, 7.5, 0 and -7.5°C) in four replicates were examined in a completely randomized design experiment. It was revealed that under low temperature stress, soluble sugar contents, proline, malondialdehyde (MDA) and hydrogen peroxide (H2O2) were increased in both turfgrasses. Antioxidant enzyme activity, particularly catalase (CAT, EC 1.11.1.6) and superoxide dismutase (SOD, EC 1.15.1.1), was increased as a result of temperature reduction from 25°C to 0°C. Tall fescue is thought to be better adapted to cold stress than common bermudagrass due to higher soluble sugar contents, proline, malondialdehyde and antioxidant enzyme activity. The results show that scavenging enzymes have a direct effect in cold season tolerance of turfgrass and improve the defense mechanism of plants, but their exact role merits further investigation.