Ye Z H, Baker A J M, Wong M H, Willis A J
Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S. Yorks, S10 2TN, UK.
Department of Biology, Hong Kong Baptist University, 224 Waterloo Rd, Kowloon Tong, Hong Kong.
New Phytol. 1997 Jul;136(3):469-480. doi: 10.1046/j.1469-8137.1997.00759.x.
Zinc, lead and cadmium tolerance in four populations of Typha latifolia raised from seed collected from metal-contaminated and uncontaminated sites were investigated. Metal concentrations in natural plant populations showed that Zn, Pb and Cd in the leaves were maintained at low levels (Zn: 22-122, Pb: 4.7-40 and Cd: 0.2-0.8 μg g d. wt), although concentrations of these metals in the associated soil-sediments (total concentrations of Zn: 86-3009, Pb: 26-18894 and Cd: 1.4-26 μg d. wt) and in the roots (Zn: 46-946, Pb: 25-3628 and Cd: 1.0-17 μg g d. wt) varied widely. Some differences were found between metal-contaminated and uncontaminated populations in terms of metal uptake under controlled conditions. Seedlings from metal-contaminated populations accumulated considerably more metals (up to nearly twice as much Zn and Pb and three times as much Cd) in roots than the uncontaminated population in a pot trial. In general, however, different populations of T. latifolia showed similar growth responses (the longest leaf elongation, the longest root elongation, shoot and root d. wt), metal uptake and indices of metal tolerance when seedlings were grown in the same metal treatment solutions or in the same metal-contaminated media under laboratory conditions. The data do not support the hypothesis that populations from metal-contaminated sites have evolved tolerance to Zn, Pb and Cd, but rather that T. latifolia shows constitutional tolerance.
对从受金属污染和未受污染地点采集的种子培育出的四个宽叶香蒲种群的锌、铅和镉耐受性进行了研究。天然植物种群中的金属浓度表明，叶片中的锌、铅和镉含量维持在较低水平（锌：22 - 122、铅：4.7 - 40、镉：0.2 - 0.8 μg g干重），尽管这些金属在相关土壤沉积物（锌的总浓度：86 - 3009、铅：26 - 18894、镉：1.4 - 26 μg干重）和根部（锌：46 - 946、铅：25 - 3628、镉：1.0 - 17 μg g干重）中的浓度差异很大。在受控条件下，发现受金属污染和未受污染种群在金属吸收方面存在一些差异。在盆栽试验中，来自受金属污染种群的幼苗根部积累的金属（锌和铅最多几乎是未受污染种群的两倍，镉是三倍）比未受污染种群多得多。然而，总体而言，当幼苗在实验室条件下的相同金属处理溶液或相同金属污染介质中生长时，不同的宽叶香蒲种群表现出相似的生长反应（最长叶伸长、最长根伸长、地上部和根部干重）、金属吸收和金属耐受性指数。这些数据不支持来自受金属污染地点的种群已进化出对锌、铅和镉耐受性的假设，而是表明宽叶香蒲具有固有耐受性。
