Sedum alfredii : A New Lead-Accumulating Ecotype

一种新的铅富集植物——富集生态型东南景天(英文)

hi a survey of plant population, Sedum alfredii Hance, a new lead (Pb)-tolerant and lead (Pb)accumulating ecotype, was found in an old Pb/Zn mining area in Zhejiang Province of China. The growth and Pb content of plant ecotypes being able to and unable to accumulate Pb were studied by hydroponic culture with different concentrations of Pb(NO3)(2). Growth of shoots of accumulating ecotype was not affected by Ph treatments up to 320 mg/L, whereas that of non-accumulating ecotype was inhibited in all Ph treatments. The Ph concentrations in the roots and shoots of accumulating ecotype increased with increasing of Pb level in the nutrient solution. The maximum Ph concentrations in the shoots and roots of accumulating ecotype were 514 mg/kg and 13 922 mg/kg, 2.27 times and 2.62 times as much as that of non-accumulating ecotype, respectively. The highest rate of Pb accumulation of accumulating ecotype was 8.62 mug/plant/d, 7.16 times as much as that of non-accumulating ecotype. Due to its fast growth rate and high Pb-accumulating ability, from a phytoremediation perspective, accumulating ecotype of S. alfredii is a potential plant species for Pb removal from contaminated soils.

对浙江一古老铅锌矿区的土壤和植物种群进行调查后发现一种新的具有耐铅特性和铅富集能力的植物———景天科景天属东南景天 (SedumalfrediiHance) ,称为铅富集生态型植物。进一步比较和分析了不同浓度硝酸铅处理对富集和非富集生态型东南景天的生长及其对铅的吸收特性的影响。结果表明 ,32 0mgPb/L处理对富集生态型的地上部分生长无显著影响 ,而非富集生态型在 2 0mgPb/L时即出现受害症状。富集和非富集生态型的地上部分铅含量、根系铅含量以及单株铅积累速率均随处理浓度的增加而表现出先升后降的变化趋势。其中富集生态型的地上部分铅含量、根系铅含量以及单株铅积累速率最高可达到 5 14mg/kg、1392 2mg/kg和 8.6 2 μg/plant/d ,分别是非富集生态型的 2 .2 7、2 .6 2和 7.16倍。由于具有生长速度快和高积累铅的能力 ,从植物修复的观点来说 ,东南景天铅富集生态型在铅污染土壤的修复方面具有巨大的潜力。