不同浓度汞对3种水生植物根系构型的影响

Effects of HgCl_2 on Root System Architecture of Three Types Hydrophyte

采用液培法研究不同浓度的HgCl_2(0,1.0,2.5,5.0,10.0,20.0,40.0,80.0 mg·L-1)对水慈姑等3种水生植物幼苗根系构型的影响。结果显示:随着营养液中HgCl_2浓度的升高,水慈姑和大花美人蕉根系总长呈先增加后降低的趋势,在2.5 mg·L-1(HgCl_2)时达最大值;水生鸢尾根系总长则随着HgCl_2浓度的增加呈持续下降;水慈姑的根系总体积、根系总表面积和根系直径随着营养液中HgCl_2浓度的升高呈先增加后下降的趋势,且均在2.5 mg·L^(-1)(HgCl_2)时达最大值,而大花美人蕉和水生鸢尾的则持续减小。由此可见,大花美人蕉、水生鸢尾对溶液中HgCl_2胁迫敏感,水慈姑在低浓度的HgCl_2胁迫下钝感,在较高浓度的HgCl_2胁迫下敏感。

The influence of various concentrations(0,1.0,2.5,5.0,10.0,20.0,40.0,80.0mg·L-1)on the root system architecture of three types hydrophyte was investigated.The result showed that with the increasing of HgCl2concentrations in nutrient solutions,the total length of Sagittaria sagittifolia L.and Canna generalis Bailey roots increased,and the highest values were observed at2.5mg·L-1HgCl2in nutrient solutions,while with the further increasing of HgCl2concentrations in nutrient solutions,the total length of roots continued to decrease.However,with the increasing of HgCl2concentrations in nutrient solutions,the total length of Iris pseudacorus L.roots continued to decrease.With the increasing of HgCl2concentrations in nutrient solutions,the average diameter,total volume of roots and surface area of Sagittaria sagittifolia L.presented increasing first and then decreasing tendency.While,with the increasing of HgCl2concentrations in nutrient solutions,these characters of Canna generalis Bailey and Iris pseudacorus L.continued to decrease.The results of this research could provide a theoretical basis for exploring the adaptation of hydrophyte under HgCl2stress.