Responses of Bermudagrass to Salinity

Bermudagrass ( Cynodon spp.) are salt‐tolerant grasses valuable for forage and turf. Experiments were conducted to determine specific responses to increasing salinity to provide a basis for breeding of more salt tolerant, agronomically desirable strains. The cultivar ‘Santa Ana’ ( Cynodon hybrid) was grown in solution cultures containing increasing levels of NaCl and CaCl 2 or K 2 SO 4 . Dry weight of tops decreased while dry weight of roots and total nonstructural carbohydrate concentrations of crowns, but not roots, increased with increased salinity of the culture solution. Net photosynthesis rates were not affected by high levels of NaCl and CaCl 2 or K 2 SO 4 , although leaf water and osmotic potentials were decreased. Increased concentrations of Na + and Ca 2+ were observed in tops and roots corresponding with decreased concentrations of K + and Mg 2+ when NaCl and CaCl 2 were used in the culture solution. When K 2 SO 4 was used to adjust the solution osmotic potential, K 2 concentrations were increased in tops and roots while Ca 2+ and Mg 2+ were decreased. Salinity tolerance of bermudagrass may be facilitated by shunting of photosynthate from top growth to root growth and carbohydrate storage, osmotic adjustment through ionic substitution and redistribution, or increased concentration of organic acids in the cell sap.