Three Species Under Saline Alkali And Heavy Metal Stress Study On The Morphological And Physiological Adaptability Of Turf Grass

With the continuous improvement of China's overall national strength and the rapid development of social and economic levels,bringing good life to people is accompanied by the emergence of environmental pollution problems.The problems of soil salinization and heavy metal pollution are increasingly serious.Soil is the material that human beings depend on to live on the earth.It is an important carrier for normal plant growth and animal life.Salinization and heavy metal pollution not only reduce the utilization rate of agricultural land in China,but also cause serious damage to plants and crops.Affect its normal growth.Saline-alkali soil contains neutral salt and alkaline salt,while heavy metal lead(Pb)and cadmium(Cd)in soil are also the most heavy metals in surface soil layer in many cities and regions in China.In this dissertation,turfgrass tall fescue(Arid),tall fescue+rye grass(Derby)and bermudagrass(Mirage)were used as the research materials.The greenhouse pots were used to simulate with NaCl and NaHCO3.Under salinity and alkali stress conditions,NaCl and NaHCO3 solutions with concentrations of 0 mmol·L-1,50 mmol·L-1,150 mmol·L-1 and 250 mmol·L-1 were prepared with distilled water and different concentrations.The Pb(NO3)2-Pb2+(0,500,1000,2000 mg/L)and 3CdSO4.8H2O-Cd2+(0,50,100,200 mg/L)aqueous solutions were used to treat three types of turfgrass respectively.And physiological indicators,etc.,explored varieties with better tolerance to salinity and heavy metals,and the results showed that:The turfgrass showed better growth status under different salt stress,and there was no phenomenon of death and wither.However,under different concentrations of alkali stress,the growth was not ideal.With the increase of the concentration of stress,the length of the leaves was longer.The growth was inhibited;the number of tillers showed a downward trend.In the early stage of treatment,the number of tillers in the turfgrass under low concentration treatment increased,indicating that mild salt stress promoted the number of tillers in turfgrass;There was a significant increase trend,indicating that the stress treatment of salt and alkali had less effect on the turfgrass root length than the aboveground part,and the relative water content decreased with the increase of the salt and alkali treatment concentration;the chlorophyll content increased with the treatment concentration.The decrease indicates that the concentration of stress is inversely proportional to photosynthesis;the root vigor of the three turfgrasses increases with increasing treatment concentration under salt stress and alkali stress.The activity of the root system first increases and then decreases,and the soluble sugar content increases.It also gradually increased,positively correlated with the treatment concentration.However,considering their morphological characteristics and physiological indexes,the tolerance levels were tall fescue>Mixed grass>bermudagrass,mixed grasses and bermudagrass could not grow under strong alkali stress.In summary,tall fescue can be cultivated as a lawn plant in saline land.The growth status of the three turfgrass species under different cadmium stress treatments was better.Under the stress treatment of lead,the growth state under high lead concentration was not ideal,and some leaves appeared yellow,but not Affect its normal growth.The chlorophyll content and root vigor of the three grasses decreased with increasing treatment concentration after being exposed to lead and cadmium,and the malondialdehyde content,peroxidase activity,and catalase activity of the three plants affected the plant metabolism.With the increase of heavy metal ion concentration,it showed an upward trend.In the turfgrass,the absorption of lead and cadmium by heavy metals is high.The less is the bermudagrass,and the mixed grass is in the middle.Therefore,tall fescue is suitable for the cultivation of heavy metal accumulation plants,and the absorption of heavy metals is For the underground part and the above ground part,the lead and cadmium treatment was integrated.The tolerance was in the order of mixed grass>tall fescue>bermudagrass.