Rajkumar K, Sivakumar S, Senthilkumar P, Prabha D, Subbhuraam C V, Song Y C
Department of Environmental Sciences, Bharathiar University, Coimbatore, 641046, Tamilnadu, India.
Ecotoxicology. 2009 Oct;18(7):952-60. doi: 10.1007/s10646-009-0371-9. Epub 2009 Jul 10.
The heavy metal (Cu, Pb, Ni, and Cd) accumulation capacity of the stem cuttings of the terrestrial, ornamental plant, Talinum triangulare was assessed in hydroponic medium. The stem cuttings of T. triangulare, grew well in distilled water regenerating roots and aerial parts. On exposure to various concentrations of Cu, Pb, Ni, and Cd, a concentration dependent decrease was observed in the number of leaves produced and roots regenerated and an increase in the number of days required for the initiation of roots. The number of leaves produced showed an increasing trend in almost all treatment concentrations of Cu, Pb, Ni, and Cd with an increase in the duration of experiment, whereas, with an increase in the treatment concentration of metals a significant (P < 0.05) decrease was observed in the number of leaves produced. The number of days required for root initiation in metal solutions, however, increased with increasing concentration of Cu, Pb, Ni, and Cd. The root development was completely arrested from 10 mg l(-1) of Ni and 4 mg l(-1) of Cd. Compared to the control, a significant decrease was recorded in the number of roots produced in all treatment concentrations of Cu, Pb, Ni, and Cd. Pink colouration of metal solution consequent to leaching of plant pigment from T. triangulare was observed which was not persistent and disappeared after a few days. Decaying of stem was observed when exposed to Ni and Cd but not to Cu and Pb. Although, copper accumulation by T. triangulare at treatment concentration of 15 and 20 mg l(-1) exceeded 1,000 mg kg(-1) dry matter, necessary pot culture experiment is required before "T. triangulare" can be definitely classified as a Cu hyperaccumulator.
在水培介质中评估了陆生观赏植物三角叶土人参茎插条对重金属（铜、铅、镍和镉）的积累能力。三角叶土人参的茎插条在蒸馏水中生长良好，能再生根和地上部分。在接触不同浓度的铜、铅、镍和镉后，观察到叶片产生数量和根再生数量呈浓度依赖性下降，且生根所需天数增加。在几乎所有铜、铅、镍和镉处理浓度下，随着实验持续时间的增加，叶片产生数量呈增加趋势，然而，随着金属处理浓度的增加，叶片产生数量显著（P<0.05）下降。在金属溶液中生根所需天数随铜、铅、镍和镉浓度的增加而增加。当镍浓度达到10 mg l(-1)和镉浓度达到4 mg l(-1)时，根的发育完全停止。与对照相比，在所有铜、铅、镍和镉处理浓度下，根的产生数量均显著下降。观察到由于三角叶土人参植物色素的浸出导致金属溶液呈现粉红色，但这种现象并不持久，几天后就消失了。当暴露于镍和镉时观察到茎腐烂，但暴露于铜和铅时未出现这种情况。尽管在15和20 mg l(-1)的处理浓度下，三角叶土人参对铜的积累超过了1000 mg kg(-1)干物质，但在将“三角叶土人参”明确归类为铜超积累植物之前，还需要进行必要的盆栽实验。
