【摘要】 以旱柳(Salix matsudana Koidz)为研究对象,采用水培方法,研究富营养化条件下重金属污染对旱柳的生长特性、生理指标以及重金属富集的影响.结果表明:50μmol/L铜(Cu)处理会显著抑制旱柳生长并引起相应的生理活动,表现为干重、相对生长速率(RGR)、耐性指数(TI)及光合色素含量降低,丙二醛(MDA)含量和过氧化物酶(POD)活性升高,且50μmol/L Cu对旱柳的毒害远大于50μmol/L锌(Zn).随着氮(N)、磷(P)浓度提高,旱柳生物量提高,MDA含量和POD活性降低,重金属对旱柳的毒害得到缓解.Cu和Zn主要富集在旱柳根部(插条新生根,下同),但随着N、P浓度的提高,旱柳根部富集Cu和Zn的量显著减少. Cu会增加旱柳根部对Zn的富集,显著降低Zn的转运系数,抑制Zn向新生枝条转运. 3种N、P组合(N0+P0、N1.5+P0.18和N15+P1.8,下同)下,与Zn50处理相比,Zn50+Cu50处理下Zn转运系数分别显著降低了62.8%、57.0%和77.9%(P <0.05);Zn会减少旱柳根部对Cu的富集,显著提高Cu的转运系数,促使Cu向新生枝条部转运.3种N、P组合下,与添加Cu50的处理相比,Zn50+Cu50处理下Cu的转运系数分别显著提高了26.0%、62.9%和42.9%(P <0.05). N、P浓度的提高会促使Zn向新生枝条部转运,与N0+P0+Zn50相比,N1.5+P0.18+Zn50和N15+P1.8+Zn50处理下Zn的转运系数分别显著提高了45.6%和247.3%(P <0.05),而对Cu的转运无显著影响.综上,旱柳插条对Cu和Zn具有很强的富集能力,N、P浓度的提高可在一定程度上缓解重金属对旱柳的毒害,减少新生根对Cu和Zn的富集并促使Zn向新生枝条转运.(图9表2参38)更多还原

【Abstract】 The effect of heavy metal pollution on growth characteristics, physiological indexes, and heavy metal accumulation was explored under eutrophication conditions using hydroponically growing Salix matsudana cuttings. The results showed that under the 50 μmol/L Cu treatment condition, cutting growth was significantly inhibited and the physiological response to stunted growth was induced, with decreasing dry weight, RGR, tolerance index(TI), and amount of photosynthetic pigment,as well as increasing MDA content and POD activity. The damage, as a result of 50 μmol/L Cu treatment in S. matsudana was more serious than that with 50 μmol/L Zn treatment. With the increase in N and P concentration, biomass increased while MDA content and POD activity decreased. Eutrophication could alleviate the damage caused by heavy metals on S. matsudana.Cu and Zn were mainly accumulated in the roots of S. matsudana cuttings. With the increase in N and P concentrations, the amount of Cu and Zn that accumulates in the root of S. matsudana cuttings decreased significantly. Accumulation of Zn in the root of S. matsudana cuttings increased when translocation factors(TF) and the transport of Zn to the shoot decreased as a result of Cu treatment. Using a combination of N and P treatments(N0 + P0, N1.5 + P0.18 and N15 + P1.8, the same below),the TF of Zn under Zn50 + Cu50 treatments significantly decreased by 62.8%, 57.0%, and 77.9%, respectively,(P < 0.05)compared with that with Zn50 only. However, the accumulation of Cu in the root of S. matsudana cuttings reduced while TF and the transport of Cu to the shoot was promoted by Zn. Using the three combinations of N and P, the TF of Cu under Zn50 +Cu50 treatments significantly increased by 26.0%, 62.9%, and 42.9%(P < 0.05) compared with treatment with Cu50 only. The transport of Zn to the shoot significantly increased with the increase in N and P concentration, but the transport of Cu did not change significantly. Compared with treatment with N0 + P0 + Zn50, the TF of Zn increased by 45.6% and 247.3%(P < 0.05)under N1.5 + P0.18 + Zn50 and N15 + P1.8 + Zn50 treatment conditions, respectively. In summary, S. matsudana has a strong ability to accumulate Cu and Zn. With the increase in N and P concentration, the toxicity of heavy metals on S. matsudana could be alleviated, and the accumulation of Cu and Zn in the root decreased as the transport of Zn to shoot increased.更多还原