Study on screening of salt concentration gradient and critical concentration on Axonopus compressus

In the present study, we took Axonopus compressus as the main research object, aiming to evaluate its ability of salt resistance. The turf quality, leaf color, and leaf firing percentage of carpet grass in different salt concentrations by hydroponics experiment were examined. The results of this study showed that there were significant or very significant differences among different treatments of salt concentration. Under the treatment of low salt concentration (0－120 mmolL-1), the scores of leaf colour and turf quality were both higher than six, meanwhile, under the treatment of high salt concentration (140－180 mmolL-1), the scores were lower than six. However, leaf firing showed a different pattern, which has a lower percentage at low concentration (0－140 mmolL-1) than that at the high concentration (160-180 mmolL-1). Taking yellow rate dropping at 50% as an index, we built a regression equation and found that the critical salt concentration of NaCl to A. compressus was 141 mmolL-1.