Abstract: Taking cold-sensitive bermudagrass (common bermudagrass and coastal bermudagrass) and cold-resistant bermudagrass (Xinnong No.1 and Kashgar bermudagrass) as the test materials, the effect of ABA (0 mg•L^-1,5 mg•L^-1, 15 mg•L^-1 and 25 mg•L^-1) on relative electric conductivity (EC), malondialdehyde content (MDA), superoxide dismutase activity (SOD), catalase activity (CAT) and peroxidase activity (POD) of leaves under 4 ℃ for 24 and 72 hours were studied. The results showed that the EC and MDA of bermudagrass were increased compared with the situation of CK2 (water spray and cultivation under room temperature) regardless of spraying ABA or not. But compared with the situation of CK1 (water spray and cultivation under 4 ℃), spray of ABA could induce the decrease of EC and MDA of bermudagrass, promote the increase of SOD activity, CAT activity and POD activity, protect the integrity of membrane system, and enhance the adaptation to low temperature. After carrying out a comprehensive analysis, it was considered that the suitable ABA concentration for cold-resistant bermudagrass was 15 mg•L^-1, that for cold-sensitive bermudagrass was 5 mg•L^-1under the consideration of adapting low temperature. With prolonging the time of low temperature, the increase rate of SOD activity and the decrease rate of MDA of cold-resistant bermudagrass were obviously higher than that of coldsensitive bermudagrass, which revealed that the difference of SOD activity was one of the reasons to cause the difference of cold resistance.

Key words: Cynodon dactylon, low temperature, abscisic acid, enzyme activity, electric conductivity