| Three warm-season turfgrasses[Zoysiagrass(Zoysia japonica), Bahiagrass(Paspalum notatum), Bermudagrass(Cynodon dactylon)] were fumigated by SOj stress with five different levels(natural state,1.5ppm,2.25ppm,3ppm,3.75ppm) in a artificial designed fumigation box. The injured symptoms,content of chlorophyll, soluble sugar,soluble protein,MDA,activites of POD,CAT,SOD and content of sulfur in leaves were tested. Based on the use of correlation analysis, subordination function method and mathematical methods to analyze data, comparison of the three turfgrasses resistant and purify ability to SO2.The results show that:After SO2treatment,the three thurfgrass represent injured symptoms,and And with the stress concentration to increase the damage suffered heavier. After SO2treatment.,the blade of Zoysiagrass began wilting,the color became celadon, lose original luster and water shortage; the leaves of bahiagrass become yellow,and the grass density declines; bermudagrass veins show the different size of point or surface form like injury spot,the leaves interveinal chlorosis show yellow. In the highest concentration of SO2, damage rate is Zoysiagrass, Bahiagrass, Bermudagrass:35%,50%,40%.After SO2treatment, the chlorophyll of three turfgrasses content become low. Chlorophyll a, chlorophyll b, total chlorophyll contents increased with the stress concentration and reduce the value of a/b down then up the trend.SO2stress, the soluble sugar content of the three kinds of turfgrass overall upward trend. Zoysia and bahia grass soluble sugar gradually increased with the increase in concentration of SO2, bermudagrass first decreased and then increased.Under S4, compared with CK, the increase quantity of the soluble sugar Zoysiagrass, Bahiagrass, Bermudagrass are29.61%,74.52%,22.58%.Among them, Bahiagrass is biggest.After SO2treatment, the soluble protein content in the film of the three kinds of lawn grass inconsistent:Zoysia soluble protein first decreased and then increased; the Bahiagrass soluble protein first increased and then dropped; soluble protein in the treatment of bermudagrass are lower than the control. With SO2increasing, MDA and Soluble protein about Zoysia japonica, Paspalum notatum and Cynodon dactylon had be increased, then on the S4all were maximum. Compared with CK, MDA increasing by41.90%,66.04%,47.26%,and Soluble protein increasing by323.83%,698.32%,272.93%, noteworthily The largest change was Paspalum notatum.Still with SO2increasing, POD, SOD and CAT activity about Zoysia japonica and Cynodon dactylon had be increased, then on the S4all were maximum. But Paspalum notatum was different, POD activity was always under CK, CAT activity had First increased and then dropped, SOD activity was same as CAT, but all was always under CK.The sulfur content about Zoysia japonica, Paspalum notatum and Cynodon dactylon had increased with SO2increasing. On the S4, increased by10.86%,71.52%,67.87%. Through the increasing, the best absorbed dose was Paspalum notatum, and the worst was Zoysia japonica. According to sulfur content, from strong to weak they were Paspalum notatum, Cynodon dactylon, Zoysia japonica.According to subordination function method, all index was through the comprehens-Ive evaluation. finally from strong to weak the resistance were Cynodon dactylon, Zoysia japonica, Paspalum notatum.The best turf grass was Cynodon dactylon on the basis of the resistance, the suffer symptoms and the purify ability.From now on, it was applied to landscaping, and then would be designed to improve and enhance the quality of air. |
