云南松华坝流域3种本土野生植物镉富集特性比较与应用

Comparison and application of cadmium enrichment characteristics of threenative wild plants in Songhuaba Basin,Yunnan Province

在镉(Cd)污染区域筛选富集能力强的本土野生植物是Cd污染土壤植物修复的路径之一。在云南松华坝流域土壤Cd含量超风险筛选值地块生长的杂草中,初步筛查表明牛膝菊、艾蒿和灰藜具有Cd富集潜力。为进一步探明其修复能力,通过盆栽和田间实验比较了这3种野生植物的Cd富集特性和修复能力。结果表明,牛膝菊和艾蒿Cd富集系数与转运系数均大于1,灰藜小于1。施肥措施不仅能显著提高3种本土野生植物的株高和地上部生物量,而且能显著提高牛膝菊地上部和根系的Cd含量、Cd转运系数和Cd富集系数。牛膝菊地上部和根系的Cd含量以及艾蒿的根系Cd含量均随土壤Cd含量的增加而增加。与艾蒿相比,牛膝菊具有更强的Cd转运和富集能力。在100 mg·kg^(-1)外源Cd添加的土壤中,牛膝菊的地上部和根系Cd含量分别为165.5 mg·kg^(-1)和147.5 mg·kg^(-1)。田间实验表明,每茬牛膝菊和艾蒿的鲜重分别为26.0 t·hm^(−2)和32.0 t·hm^(−2),可分别带走Cd3.29 g·hm^(−2)和3.35 g·hm^(−2),均可用作当地土壤修复的备选植物。该结果可为相似环境下的土壤镉污染植物修复材料的选择提供参考。

It is one way of phytoremediation of Cd-contaminated soils by selecting native wild plants with cadmium(Cd)enrichment ability in Cd-contaminated soils.Preliminary screening showed that Galinsoga parviflora Cav.,Artemisia argyi Levl.et Van,and Chenopodium glaucum L had the potential for Cd enrichment among weeds growing on the field with soil Cd content exceeding risk screening value in the Songhuaba region of Kunming.In order to further explore their remediation capabilities,the enrichment characteristics and remediation capabilities of these three native wild plants were compared in pot and field experiments in this study.The results showed that the Cd translocation factor and bioaccumulation factor of G.parviflora and A.argyi were greater than 1,and that of C.glaucum was less than 1.Fertilization could not only significantly increase the plant height and shoot biomass of these three native wild plants,but also significantly increase the Cd contents,translocation factor,and bioaccumulation factor of the shoots and roots of G.parviflora.The Cd contents in the shoots and roots of G.parviflora and roots of A.argyi were increased with the increase of soil Cd contents.Compared with A.argyi,G.parviflora had stronger Cd transport and enrichment capabilities.In the soil applied with 100mg·kg^(-1)Cd,the Cd contents in the shoots and roots of G.parviflora were 165.5mg·kg^(-1)and 147.5mg·kg^(-1),respectively.The field application experiment showed that G.parviflora had stronger Cd enrichment ability and A.argyi had higher biomass.The field experiment showed that the fresh weights of G.parviflora and A.argyi in each crop were 26.0 t·hm^(−2)and 32.0 t·hm^(−2),respectively.G.parviflora and A.argyi could transfer 3.29 g hm−2 and 3.35 g hm−2 of Cd,respectively,and they are potential phytoremediators for local soil Cd contamination.