Senecio conrathii NEBr. (Asteraceae), a new hyperaccumulator of nickel from serpentinite outcrops of the Barberton Greenstone Belt, South Africa
Senecio conrathii NEBr. (Asteraceae), a new hyperaccumulator of nickel from serpentinite outcrops of the Barberton Greenstone Belt, South Africa
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DOI：
10.1007/s11284-017-1541-5
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发表时间：
2018-05-01
影响因子：
2
通讯作者：
Rajakaruna, Nishanta
中科院分区：
文献类型：
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作者：
Siebert, Stefan John;Schutte, Nadine Carol;Rajakaruna, Nishanta
在南非的超镁铁质露头中已知有五种属于菊科的镍超富集植物。已知的菊科超积累植物（例如本土的 Berkheya coddii Roessler）的植物修复应用已得到充分报道，需要进一步探索以找到具有此类特征的其他物种。这项研究针对的是巴伯顿绿岩带的八个随机选择的蛇纹岩露头中最常见的菊科物种。对 20 个物种进行了采样，其中 12 个物种是首次进行镍积累测试。尽管大多数物种都是排除者，但已知的超积累者 Berkheya nivea N.E.Br.和 B. zeyheri (Sond. & Harv.) Oliv。 ＆希恩亚种。地黄 (Thell.) Roessler var. rogersiana (Thell.) Roessler 在叶子中超积累了预期水平的镍。发现了一种新的镍超富集植物千里光（Senecio conrathii N.E.Br.），它在土壤中的叶子中积累了1695+/-637 A mu g g(-1)的元素，总镍含量和可交换镍含量分别为503 mg kg(-1)和0.095 A mu g g(-1)。这使其成为继千里光异色千里光 (Senecio anomalochrous Hilliard) 和千里光 (Thunb.) Harv. 之后，南非千里光科中第三种已知的超积累镍的物种，尽管与后者相比，它的蓄积能力较弱。目前，南非已对菊科的七个部落进行了超积累情况筛查，其中仅记录了 Arctoteae 和千里光科的超积累情况。这表明对超富集植物的进一步探索应集中在这些族群上，因为它们包含所有六种超富集镍的物种（迄今为止筛选的 68 个菊科类群）。
Five nickel hyperaccumulators belonging to the Asteraceae are known from ultramafic outcrops in South Africa. Phytoremediation applications of the known hyperaccumulators in the Asteraceae, such as the indigenous Berkheya coddii Roessler, are well reported and necessitate further exploration to find additional species with such traits. This study targeted the most frequently occurring species of the Asteraceae on eight randomly selected serpentinite outcrops of the Barberton Greenstone Belt. Twenty species were sampled, including 12 that were tested for nickel accumulation for the first time. Although the majority of the species were excluders, the known hyperaccumulators Berkheya nivea N.E.Br. and B. zeyheri (Sond. & Harv.) Oliv. & Hiern subsp. rehmannii (Thell.) Roessler var. rogersiana (Thell.) Roessler hyperaccumulated nickel in the leaves at expected levels. A new hyperaccumulator of nickel was discovered, Senecio conrathii N.E.Br., which accumulated the element in its leaves at 1695 +/- 637 A mu g g(-1) on soil with a total and exchangeable nickel content of 503 mg kg(-1) and 0.095 A mu g g(-1), respectively. This makes it the third known species in the Senecioneae of South Africa to hyperaccumulate nickel after Senecio anomalochrous Hilliard and Senecio coronatus (Thunb.) Harv., albeit it being a weak accumulator compared with the latter. Seven tribes in the Asteraceae have now been screened for hyperaccumulation in South Africa, with hyperaccumulators only recorded for the Arctoteae and Senecioneae. This suggests that further exploration for hyperaccumulators should focus on these tribes as they comprise all six species (of 68 Asteraceae taxa screened thus far) to hyperaccumulate nickel.