Effect of salinity on Puccinellia distans (L.) Parl. treated with NaCl and foliarly applied glycinebetaine

Turfgrasses general appearance is much affected by environmental stresses because the species used for this purpose are particularly exigent in terms of technical inputs and water need. In the Mediterranean area, sometimes irrigation is provided by using waste water which may contain high concentrations of dissolved salts which can cause salt stress injury and poor turf quality. Puccinellia distans (L.) Parl. is a halophyte cool season grass that seems to have a high salinity tolerance when cultivated in sodic soils or in NaCl-rich hydroponic cultures. We investigated the response of P. distans to salinity in a soil culture in a controlled growth environment. The effect of different concentrations of NaCl (85, 275 and 600 mM) on shoot and root growth and chloride content was assessed. After determining the resistance of P. distans to the highest salinity level, we tested the efficiency of the osmoprotectant glycinebetaine (GB) in reducing salt stress effects by measuring some physiological parameters. The results showed a very good adaptability of P. distans to salinity conditions. When irrigated with salt solution at the highest concentration (600 mM), plants showed a reduction in growth rate and biomass production that seemed to be relieved by GB application. With GB application, leaf relative water content and biomass production were similar to the control. However, GB application did not result in a generally better turf quality compared to untreated plants, so it did not give a relevant advantage in reducing technical and labor inputs with respect to the maintenance of a P. distans turf.