土壤与大气Cu处理下迎春的耐性和富集特征研究

Tolerance and enrichment characteristics of Jasminum nudiflorum under copper treatment from soil and atmosphere

关键词:  Cu处理, 迎春, 土壤和大气沉降处理, 耐性, 富集

Key words:  copper(Cu)treatment, Jasminum nudiflorum, soil and atmospheric deposition treatment, tolerance, enrichment

摘要:

作为北京市常见园林灌木树种之一,迎春(Jasminum nudiflorum)因其在早春独特的观赏性而深受市民喜爱。Cu污染是北京市较为严重的重金属污染类型之一。为探讨迎春对城市Cu污染的修复作用,该文通过模拟北京市土壤和大气Cu污染条件,采用盆栽试验,设置9种不同浓度的土壤和大气Cu处理,以验证迎春Cu富集能力及生理生长特性。结果表明:(1)土壤和大气沉降处理均能显著增加迎春根、茎、叶中的Cu含量,其中土壤贡献率为63.48%～96.99%。各处理中Cu含量均表现为根>茎>叶。(2)大气处理下光化学转化效率(F_v/F_m)和相对叶绿素含量(SPAD值)提高,初始荧光(F0)降低,光合能力增强,而土壤处理及土壤和大气双重处理则对迎春的光合作用产生抑制影响。(3)与大气处理相比,土壤处理及土壤和大气双重处理导致活性氧(ROS)积累增多,膜脂过氧化作用加剧,丙二醛(MDA)含量大幅升高,抗氧化酶活性与脯氨酸(PRO)含量逐渐下降,造成生物膜系统损伤。(4)低浓度Cu处理对迎春生长有促进作用,而高浓度Cu处理(SHAL、SHAH)则抑制迎春生长,迎春根系耐性指数(TI)最小值为69.19%,属于高耐受型植物。综上认为,在模拟北京市Cu污染处理下,迎春可以在维持自身正常生理生长活动的同时,有效吸收土壤和大气中的Cu。该研究结果为北京市Cu污染防治、生态环境修复提供一定的理论依据。

Abstract:

As one of the common garden shrub species in Beijing, Jasminum nudiflorum is very popular among citizens for its unique ornamental properties in early spring. Copper(Cu)pollution is one of the most serious heavy metal pollution types in Beijing. To explore the remediation effect of J. nudiflorum on urban copper pollution. By simulating the soil and atmospheric copper pollution conditions in Beijing, pot experiments were conducted to set up nine different concentrations of soil and atmosphere Cu treatments to verify the Cu enrichment ability and physiological growth characteristics of J. nudiflorum. The results were as follows:(1)Soil treatment and atmospheric deposition treatment and were able to significantly increase Cu content in root, stem and leaf of J. nudiflorum, among them, the contribution of soil ranged from 63.48% to 96.99%. The Cu content in each treatment showed the order of root>stem>leaf.(2)Under atmospheric treatment, photochemical conversion efficiency(F_v/F_m)and relative chlorophyll content(SPAD value)were increased, initial fluorescence(F0)was decreased, and photosynthetic capacity was promoted. The photosynthesis of J. nudiflorum was inhibited by soil treatment and co-treatment with soil and atmosphere.(3)Compared with atmospheric single factor treatment, soil single factor treatment and co-treatment with soil and atmosphere resulted in increased accumulation of reactive oxygen species(ROS), increased membrane lipid peroxidation, increased malondialdehyde(MDA)content, and decreased antioxidant enzyme activity and proline(PRO)content, and finally led to damage of the biofilm system.(4)The low-concentration Cu treatment promoted the growth of J. nudiflorum, while the high-concentration copper treatments(SHAL, SHAH)inhibited the growth of J. nudiflorum. The minimum value of the root tolerance index(TI)of J. nudiflorum was 69.19%, which indicated that J. nudiflorum belonged to a highly tolerant plant. In conclusion, under the simulated treatment of soil and atmosphere Cu pollution in Beijing, J. nudiflorum can effectively absorb and enrich Cu in soil and atmosphere while maintaining its own normal physiological and growth activities. This conclusion provides a certain theoretical basis for the prevention and control of Cu pollution and the maintenance and restoration of the ecological environment in Beijing.