Study On Salt Tolerance Of Ya,an Wild Centipedegrass In Sichuan

In order to improve the utilizing value of wild centipedegrass breeding resource materials and adapt the requirement of critter improve pickled soil, a series of physiological responses to the salinity of the Ya'an tamed wild centipedegrass [Eremochloa ophiruoides (Munro.) Hack.Jwere studied. In the experiment and we can induce The salinity tolerance range from the study. Ya'an centipedgrass was cultivated in pot or water at different salinity density (0.1%,0.2%,0.3%,0.4%,0.5%,0.6%-quality percentage). The survival rate and wilting degree and the electric conductivity rate ,proline ,chlorophyll,water potential and H2O2 enzyme activity of leaf were observed each of 6 days for 36 days after treatment. The result showed: Changes of plant morphology of Ya'an centipedegrass under the salinity stress was behind of the changes of physiology .The plant underwent the different stage of "normal" , "wilting", "death" in the different salinity density. With the increasing of treat salinity density and time , its normal growth progress was decreased while its rapidity and degree of wilting and numbers of plant death were increased. The plants showed the normal growth at 0.1% , light wilt at 0.2% , middle wilt at 0.3%, serious wilt at 0.4% and dead at 0.5% while the survival rate were 100%,90%,50% and zero respectively. At the same time the change of leaf color was from green to yellow even fading and the change of leaf texture was from soft to hard with the increasing of the treat of salinity density and time .By study, the relative electric conductivity rate and proline concentration increased while the chlorophyll concentration and water potential decreased with the increasing of treat salinity density and time. For example, in the sixth day of treat, from the salinity density of 0.1% to 0.4%, the relative electric conductivity and the proline concentration increased 1.6 and 3.16 times respectively while the chlorophyll concentration and water potential decreased 21.1% and 67.2% respectively. In the thirty sixth day of treat, the relative electric conductivity and the proline concentration increased 2.38 and 15.3 times respectively while the chlorophyll concentration and water potential decreased 81.2% and 100.1% respectively. H2O2 enzyme activity ascended from the beginning then descended. Its concentration reach max value (3.17) in the eighteenth day under the treated of 0.2%. By correlation analysis, all of the physiological quotas were related to the treat salinity density.Among them , The changes of proline concentration, relative electric conductivity rate and chlorophyll concentration were high significant correlation to it and the correlation coefficients were 0.947,0.943,0.910 respectively. While The water potential and H2O2 enzyme activity were significant correlation to it and the correlation coefficients were 0.883,0.745s respectively. By regress analysis, the relative electric conductivity rate and proline concentration were exponential positive correlation to salinity density and the R2 were 0.973 and 0.929 respectively. The water potential and chlorophyll concentration were linear negative correlation to it and the R2 were 0.959 and 0.984 respectively .The H2O2 enzyme activity was correlation to it on quadratic equation fitting and the R2 was 0.79. The proline , conductivity rate and chlorophyll were the best quotas to evaluate the salt tolerance of centipedegrass. That is, the more the increasing extent of proline concentration, chlorophyll concentration are high while the relative electric conductivity rate was low. The more salt tolerance is high. By logistic curve analysis, the salt tolerance point of inflection of Ya'an cetipedegrass were 0.21% and 0.43% respectively. It was means Ya'an cedipedegrass could grow normally under the salinity density less than 0.21%and could survive during the 0.21%~0.43% and the plants were dead when the salinity density exceed 0.43%.