6种植物对Pb的吸收与耐性研究

RESEARCH ON LEAD UPTAKE AND TOLERANCE IN SIX PLANTS

为了选择和筛选重金属Pb的耐性与富集植物 ,在温室砂培盆栽条件下对铅锌尾矿区附近生长的 6种植物 (山野豌豆 (ViciaamoenaFisch)、草木樨 (MelilotussuavenaLedeb)、披碱草 (ElymusdahuricusTurca)、酸模 (Rumexace tosa)、紫苜蓿 (Medicagosativa)和羽叶鬼针草 (BidensmaximowiczianaOett) )体内Pb的含量与分布、重金属Pb的迁移总量、根系的耐性指数做了研究 ;拟定了 6种植物对Pb的耐性临界值。Pb设了 6个浓度梯度 (10 0、2 0 0、40 0、80 0、10 0 0、15 0 0mg·L-1) ,研究结果表明 :1)随着Pb离子浓度的增高 ,羽叶鬼针草、酸模茎叶和根系含Pb量也增高 ,在 15 0 0mg·L-1浓度下含Pb量达最大值 ,而其它 4种植物体内Pb的含量先增加后降低 ;2 )随着Pb处理浓度的增加 ,羽叶鬼针草地上部迁移总量在Pb处理浓度为 5时高达 11.2 9mg ,酸模在Pb处理浓度为 6时地上部迁移总量为 9.17mg;3)羽叶鬼针草和酸模的根系耐性指数较高 ,分别为 1.6 3(Pb处理浓度为 1时 )、1.42 (Pb处理浓度为 2时 ) ,其它 4种植物的根系耐性指数在 1.0左右。结论 :羽叶鬼针草和酸模能够富集重金属Pb ,对Pb有很好的耐性 。

To identify plants hypertolerant to heavy metal lead (Pb), the content and distribution of lead, total heavy metal translocation of lead, and the index of root tolerance of six dominant species established in the vicinity of a Pb/Zn mine tailings pond were researched in this study. The six plants studied were Vicia amoena, Melilotus suaveolens, Rumex acetosa, Elymus dahuricus, Medicago sativa, and Bidens maximowicziana. The six set concentrations of lead were 100, 200, 400, 800, 1000, and 1500 mg·L -1. The major results are as follows:1) The lead content in above-ground parts and roots of Bidens maximowicziana and Rumex acetosa increased linearly with Pb concentration. The lead content trends for the other four species increased with increased Pb concentration to a certain point and then declined. 2) The total heavy metal translocation of Bidens maximowicziana and Rumex acetosa, (10.5 mg and 9.9 mg, respectively) are higher than the other four plants. 3) The index of root tolerance of Bidens maximowicziana and Rumex acetosa are dramatically higher than for the other plants. We conclude that Bidens maximowicziana and Rumex acetosa, which are tolerant to Pb, could translocate lead from the root to the stems and leaves, and so they should be preferred agents for phytoremediation of lead polluted areas. Physiological activities of the other four plants are destroyed with Pb treatment of 1500 mg·L -1.