砷在超富集植物蜈蚣草羽片中的分布规律
王学礼1，2*，韦燕燕1*，何 冰1，雷 梅2，顾明华1**
【摘 要】摘要：【目的】探明砷在超富集植物蜈蚣草不同叶位羽片中的分布，为优化采样方法进而准确评估植物修复效率提供依据。【方法】采用大田取样与室内分析相结合的方法，研究不同叶位的蜈蚣草羽片中砷分布的规律。【结果】蜈蚣草不同叶位羽片中砷浓度差异较明显：中部羽片砷浓度分别是基部羽片和顶部羽片的35%和37%，由基部羽片到顶部羽片砷浓度变化现先降低后升高的变化趋势，随着羽片叶位增加呈“U”型分布。蜈蚣草羽叶中部羽片砷富集量是基部羽片的3.1倍，是顶部羽片的2.8倍，蜈蚣草羽叶砷富集量中部羽片较高，基部羽片和顶部羽片较低，呈倒“U”型分布。【结论】中部羽片砷浓度较低，但砷累积量较大，因此通过采集羽片样品来评估蜈蚣草修复效率时要兼顾底部羽片、中部羽片和顶部羽片。 【期刊名称】南方农业学报 【年(卷),期】2015(046)005 【总页数】5
【关键词】蜈蚣草；砷；羽片；富集；分布
0 Introduction
【Research significance】P.vittata L.，the firstknown arsenic （As） hyperaccumulator （Ma et al.，2001； Chen et al.，2002），is a relatively fast-growing perennial fern.It can accumulate a huge biomass and high concentrations of As in its above ground parts，containing up to 5070 mg/kg As on a dry weight basis（Chen et al.，2002）.The
information on accumulation of As and its distribution in pinnae of P.vittata L.was limited.Research on this topic will further our understanding of the process of As absorption and transport in P.vittata，and will provide information that will optimize collection of plant samples for phytoremediation projects.Appropriate sample collection techniques will allow accurate evaluation of phytoremediation efficiency，and will help to determine the best planting density for phytoremediation of As-contaminated soil.Therefore，the aim of this study is to reveal accumulation of As and its distribution in pinnae of P.vittata L.【Research progress】P.vittata had been proven to successfully remediate As-contaminated soils （Chen et al.，2007）.Previous studies reported that most amount of As accumulated in the pinnae of P.vittata（Lombi et al.，2002；Zhou et al.，2014； Ye et al.，2014）.Synchrotron radiation-X-ray fluorescence spectrometry analysis showed that the P.vittata root is able to transport As from the cortex to the vascular tissues，from which it was quickly transported from the xylem of the frond rachis to the cortex and epidermis cells（Huang et al.，2004a； Huang et al.，2011； Wan et al.，2014）.Studies on chloroplast ultrastructure showed that addition of high concentrations of As did not damage chloroplast structure in new fronds，but had severe negative effects on chloroplast membrane structure in mature secondary pinnae （Li et al.， 2005； Shen et al.，
2014a，2014b）.The variation in As concentration among P.vittata pinnae of different ages could be up to 36% （Ma et al.，2007），with the maximum As concentrations in older fronds，and the minimum in younger fronds （Tu and Ma，2005； Zhang et al.，2012）. 【Research breakthrough point】There is no report about the relationship between pinna phyllotaxy of hyperaccumulator P.vittata L.and As distribution，which is directly related to the representation of the samples and then affect
the
accuracy
of
the
evaluation
of
phytoremediation
efficiency.P.vittata plants were collected from an As-phytoremediation field in Hunan province in this study，and the differences in As distribution in pinnae between fronds with low and high As concentrations were studied. 【Solving problems】Field sampling and laboratory analysis were used to research As accumulation and distribution in pinnae of hyperaccumulator P.vittata L.，which will provide the basis for reasonable collecting plant samples and then evaluate the phytoremediation efficiency in phytoremediation projects accurately.
1 Materials and methods
1.1 Sampling area
P.vittata plants were collected from an As-phytoremediation field in Hunan Province in December 2013，in central southern China.The As concentration in the soil ranged from 36 to 98 mg/kg.The sample
砷在超富集植物蜈蚣草羽片中的分布规律
