Simultaneously evaluation of physiological and biochemical responses in the leaves and roots of common Iranian bermudagrass [Cynodon dactylon L. (Pers.)] accessions that can tolerate a wide range of temperature fluctuations

Abstract

Abstract The average temperature of the earth's surface is increasing swiftly, negatively affecting the urban space's green cover. Using local genetic variation based on retrieving native populations has been proposed as a useful option to deal with global warming and preserve turfgrass quality. In this study, to identify Iranian common bermudagrass [Cynodon dactylon L. (Pres.)] accessions which could endure a wide range of temperature fluctuations, eight Iranian accessions of common bermudagrass were collected from eight provinces with different climatic conditions including Taft, Naein, Malayer, Gardane-Heyran, Safashahr, Gorgan (as cold tolerant accessions) and Ahvaz (as a native accession to tropical regions) along with a foreign cultivar (California origin named Blackjack). They were subjected to five temperature regimes, including 35/30°C, 40/35°C, 45/40°C, 50/45°C, and 50/50° day/night cycles for 21 days. Evaluation of physiological parameters (total chlorophyll, leaf relative water content, electrolyte leakage, root viability and total soluble proteins), osmolytes (proline, total soluble carbohydrates and starch), antioxidants (superoxide dismutase, ascorbic peroxidase, catalase, and peroxidase enzymes) in the leaves and roots simultaneously revealed that among investigated accessions Gorgan with low electrolyte leakage in leaves and starch storage in roots and high Tchl, RWC, antioxidant enzymes activity and total soluble carbohydrates in leaves and roots could endure the harsh conditions of the 50/45°C temperature regime with acceptable turfgrass quality. Gorgan can endure almost 65°C temperature fluctuations and could be introduced as a cold- and heat-stress tolerant accession. These findings provided that a heat tolerant plant with controlling respiratory rate in roots and efficiently breaking down starch storage to carbohydrates could provide the energy required for whole plant metabolic activities. This experiment also highlights the importance of simultaneously investigating evaluated parameters in leaves and roots.