超富集植物短毛蓼对锰的富集特征

Accumulating characteristics of manganese by Polygonum pubescens Blume

通过野外调查和营养液培养试验,研究了锰在短毛蓼体内的富集特征和对其生长的影响。在锰含量高达2.5×105mg/kg的锰矿废弃地上短毛蓼生长良好,叶锰含量高达1.66×104mg/kg。营养液培养条件下,随着生长介质中Mn浓度的升高,短毛蓼根、茎、叶中的Mn含量逐渐增加,当锰供应水平为1.000mmol/L时,叶锰含量超过10000mg/kg;当锰供应水平为20.000mmol/L时,短毛蓼仍能生长,根、茎和叶3部分的锰含量均达到最大值,分别为9923,18112mg/kg和55750mg/kg。在所有锰供应水平下,短毛蓼茎和叶中的锰含量都比根部的高。结果表明,短毛蓼是一种锰超富集植物,这一发现为锰污染土壤的植物修复和探讨锰在植物体内的超富集机理提供了一种新的种质资源。

Field surveys and hydroponic experiments were conducted to investigate growth responses of Polygonum pubescens Blume to Mn and its ability to accumulate this metal.A maximum Mn concentration in leaf dry matter was found to be 16649mg/kg.The plant grows well on Mn mine wasteland in Guangxi with a Mn concentration as high as 250000 mg/kg.Under hydroponic conditions,the Mn concentration in the tissues of the plants increased with increasing solution concentrations.At 1 mmol/L Mn the Mn concentration in the leaves exceeded 10000mg/kg.At 20mmol/L,the plant still survived with maximum Mn concentration in the roots,stems and leaves reaching 9923,18112 and 55750mg/kg respectively.The Mn concentrations in the stems and leaves of the plants were greater than in the roots in all the Mn treatments.Our results suggest that P.pubescens is a Mn hyperaccumulator.This species may provide a potential new resource for use in the phytoremediation of Mn-contaminated soils and as a tool for exploring the mechanisms of Mn hyperaccumulation in plants.