Salinity tolerance among a large range of bermudagrasses (Cynodon spp.) relative to other halophytic and non-halophytic perennial C4 grasses

•A wide range of genetic variation for salt tolerance in bermudagrass was identified.•The best salt tolerance was selected from saline natural environments.•There was no correlation between salt tolerance and drought resistance.•Measuring canopy temperature differential has potential as a quick and inexpensive method of selecting for salt tolerance.•Salinity levels above 20dSm−1 for 8 weeks was effective for detecting large variation for salt tolerance in bermudagrass.