Genotypic variation in salinity tolerance of Distichlis spicata turf ecotypes

Water quantity and quality issues are accelerating the search for alternative xeriphytic and halophytic turf species. Growth and physiological responses to salinity of eight Distichlis spicata (L.) Greene genotypes were observed to elucidate salinity tolerance mechanisms operating in the species. Accession 1043 was superior in salinity tolerance to other genotypes, as indicated by percentage canopy green leaf area, relative (to control) shoot growth, relative root growth, and rooting depth, when exposed to increasing salinity up to 1.0 mol/L NaCl. Salinity tolerance was associated with complete, though minimal, shoot osmotic adjustment, maintenance of low shoot saline ion levels, and high shoot K⁺/Na⁺ ratios, all of which were facilitated by high leaf salt gland ion excretion rates.