| There are many native bermudagrass resources in China, which obtained much recognition of researchers. In the experiment, five native bermudagrass (2011, 2046, Q17, M28 and J7) collected from Sichuan were selected as experimental materials, and two hybrid bermudagrass cultivar (Jackpot and Tifdwarf) were selected as check. We studied the change of morphological characters and physiological and biochemical characters of every bermudagrass under different drought stress. At the same time, the drought resistance of seven experimental materials were estimated synthetically.The results showed as follows:1. Bermudagrass of different origin held different drought resistance and their own physiological and biochemical mechanisms during the drought stress. Among the seven tested bermudagrass, 2046 was the most resistant to drought stress, and its value of drought resistance was fifty-six, while Tifdwarf was the weakest, its value of drought resistance was fourteen. Among the five wild bermudagrass, 2046 was the most resistant to drought stress, while M28 was the weakest.2. With the decreasing of water content of soil, green leaves and chlorophyll content decreased constantly under drought stress. The experiment showed the green leaves and chlorophyll content changed significantly (P<0.01) among the tested bermudagrass. And chlorophyll content of each native bermudagrass 2046, J7, 2011, Q17 and M28 reduced 0.87mg/gFW, 0.89 mg/gFW, 1.0 mg/gFW, 1.01 mg/Gfw and 1.12 mg/gFW, while Jackpot and Tifdwarf reduced 1.35 mg/gFW and 1.58 mg/gFW.3. WSD and MDA content increased constantly under drought stress in the tested bermudagrass. The result of experiment showed: The increasing velocity of WSD and MDA content of Jackpot and Tifdwarf were quicker significantly than 2046, 2011, J7 and Q17(P<0.01).4. Cell membrane permeabilities of every tested bermudagrass firstly increased slowly,secondly decreased properly, then increased sharply to the maximum under the drought stress. The proline contents increased gradually at prophase of drought stress, then increased quickly, the proline contents of all tested objects reached peak value in 28days, subsequently, with the intensifying of drought stress, the content of proline decreased sharply. Among the tested bermudagrass, the value of proline contents of 2046, J7 and Q17 (37.12mg/gFW, 29.24mg/gFW, 29.43mg/gFW) were bigger significantly than Jackpot (24.18mg/gFW) and Tifdwarf (9.82 mg/gFW) (P<0.01).5. The activities of SOD firstly increased slowly, then decreased under the drought stress in some of the seven different bermudagrass. The activities of SOD of Jackpot, Tifdwarf and M28 reached the highest level in four weeks, while that of 2011, 2046, Q17 and J7 increased continually in five weeks. During the whole drought stress, the activities of SOD of 2011, 2046, Q17 and J7 higher significantly than that of Jackpot and Tifdwarf6. The relationship between the drought resistance abilities and antioxidation abilities of the tested bermudagrass. Among the seven bermudagrass, the drought resistance abilities and antioxidation abilities of 2046 were the most, and that of Tifdwarf were the weakest. Further more, the sequence of drought resistance abilities and antioxidation abilities were consistent in all tested bermudagrass. Thus, the drought resistance of the bermudagrass showed no difference from the antioxidation ability under the drought stress.7 The results of synthetical estimating on the drought resistance for seven tested bermudagrass showed their drought resistance abilities as followings: 2046>J7>2011> Q17>Jackpot>M28>Tifdwarf.8.Through studying on physiological and biochemical mechanism under drought stress and synthetical estimating on the drought resistance, the result of disquisition indicate: native bermudagrass 2046 possessed of the worth of exploiture because of its strong drought resistance abilities and antioxidation abilities; and it was necessary to pursue roundly research on J7 and 2011 for their better drought resistance; while M28 was unsuitable exploited directly for drought region because of its weak drought resistance.
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