重金属胁迫对天竺葵生长及生理特性的影响

Effect of heavy metal stress on the growth and physiological characteristics of Pelargonium hortorum

为探讨天竺葵(Pelargonium hortorum)对不同重金属的抗性,通过温室盆栽方式,研究了不同浓度的Pb2+、Cd2+、Cu2+、Zn2+对天竺葵生长和生理特性的影响。结果表明,天竺葵植株在4种重金属胁迫下,生长均受抑制,但抑制表现程度有所不同。其中对根长的抑制最明显,但植株依然能保持生长。随着重金属浓度的升高,植株生物量均呈下降趋势,叶片相对电导率均显著上升(P <0.05),叶绿素、可溶性蛋白和游离脯氨酸含量以及过氧化氢酶(CAT)、超氧化物歧化酶(SOD)、过氧化物酶(POD)活性均显著(P <0.05)高于对照。在浓度低于1 000 mg·kg–1的Pb2+和浓度低于800 mg·kg–1的Zn2+胁迫下植株没有出现明显萎黄,其余处理下基部2～3片叶出现萎黄脱落情况。综上所述,天竺葵对4种重金属均有一定的耐性,是利用重金属污染土壤的潜力花卉。

The effects of different concentrations of Pb^2+, Cd^2+, Cu^2+, and Zn^2+ on the growth and physiological characteristics of Pelargonium hortorum were studied. Results showed that the growth of P. hortorum stressed by four types of heavy metals was inhibited by different degrees, with root length being the most significantly inhibited. However, despite this inhibitory effect, the plants continued to grow. With increasing concentrations of heavy metals, the plant biomass decreased, whereas leaf relative conductivity was significantly increased (P < 0.05). Chlorophyll, soluble protein, and free proline contents and catalase(CAT), superoxide dismutase(SOD), and peroxidase(POD) activities were significantly (P < 0.05) higher intreated plants than in the control plants. Plants did not show obvious withering when Pb^2+ concentrations were less than 1 000 mg·kg–1 and Zn^2+ concentrations were less than 800 mg·kg–1, whereas under other treatments, two or three basal leaves had withered and abscised. Therefore, P. hortorumshows some tolerance to four different heavy metals, and was fix potential of the types for using the heavy metal contaminated soil.