Research On Drought And Salt Resistance Of The Several Bermudagrass Cultivars

Bermudagrass[Cynodon.Dactylon(L.)Pers.]is a kind of perennial warm season grass with developed stolons and rhizomes,widely distributed in warm semi-humid zone, warm wet zone in the world.By taking the two local Bermudagrass new strains selected by Agricultural university of Hebei and the two cultivars pushed out by the USA recently as the research objects,the change of morphology,appearance performance,the physiological and biochemical index of the plant under drought and salt stresses were observed and measured,the drought resistance and salt tolerance of the four Bermudagrass materials were comprehensively evaluated in the experiment.The results were as follows:1.During the drought,green leaf ratio and relative water content of the bermudagrass materials were declined with the intensification of stress degree.Decrease amplitude was different in the materials,the order was:A3＞A5＞C1＞C3.MDA contents and membrane permeability increased gradually,with the maximal increase slope of A5,the C land A3 second,and the C3 was the smallest.2.Under the drought stress,chlorophyll content increased to the peak after the 6 days' stress,then declined gradually,with the A5 decreased first,the C3 second,the A3 and C1 last.Pro content of the materials increased to the peak at the 10th day,and quickly declined with the extend of stress time and increase of drought degree.The proline content was significantly different in the materials,with C3 and C1 first,325.47ug/g and 324.16μg/g,A3 second,306.56μg/g,and A5 the last,277.19μg/g.3.Under salt stress,the relative water content and the chlorophyll content of materials reduced gradually with the increase of salty stress concentration and the extension of time.The MDA content and the protoplasmic membrane injury rate gradually increased. The proline content elevated gradually in the early period and low concentration,till to the peak,and then gradually dropped.4.The effect of salt stress and drought stress on the chlorophyll fluorescence parameters of leaves was great,fluorescence value reduced gradually with the stress intensity,and the results were significantly different.So it was feasible to use the different responses of varieties to the stress to choose varieties with high stress-resistance.5.Significant difference exists in the four materials resistance.Under water stress,the drought-resistance of C3 was the strongest,its value of drought resistance was 30.C1 and A3 was second,their values of drought resistance were 28 and 21,the drought-resistance of A5 was the worst and its value of drought resistance was only 8. The order of the four materials salt tolerance was A3＞C3＞C1＞A5.6.Through studying on physiological and biochemical mechanism under drought stress and synthetical estimating on the drought resistance,the result of disquisition indicate: bermudagrass C3 and C1 possessed of the worth of exploiture because of its strong draught resistance abilities;and it was necessary to pursue roundly research on C3 for their better drought resistance;while A5 was unsuitable exploited directly for drought region because of its weak drought resistance.