Abstract:

Effects of individual and combined pollution of Pb and Cd on the growth of forage sorghum and the accumulation abilities of Pb and Cd were measured and analyzed using the method of pot experiment. Results showed that plant height and biomass of sorghum decreased with the increase of Pb, Cd concentration, whereas the Pb and Cd content of sorghum increased. The Cd content and accumulation of stem were higher than that of leaf, whereas the Pb content and accumulation of leaf were higher than that of stem. Both low and middle concentrations of Pb and Cd could mutually promote the uptake and accumulation of Pb and Cd under Pb and Cd combined stress, while high concentrations of Pb and Cd could mutually inhibit the uptake and accumulation. The enrichment capacity of Cd in forage sorghum was higher than that of Pb. These results provide theoretical bases for repairing heavy metal polluted soil using forage sorghum.

Key words: Pb, Cd, Forage sorghum, Height, Biomass, Enrichment

摘要：

采用盆栽试验研究了不同浓度的土壤外源重金属Pb，Cd及其复合胁迫对饲用高粱（Sorghum vulgare）生长的影响及其对Pb和Cd的积累能力。结果表明：随着Pb和Cd单一及复合胁迫浓度的增加，饲用高粱株高、生物量呈降低趋势，Pb和Cd含量呈增加趋势，茎鞘Cd含量及Cd累积量高于叶片，叶片Pb含量及Pb累积量高于茎鞘。在复合胁迫下，低、中浓度的Pb和Cd处理表现出相互促进吸收累积，高浓度处理表现出相互抑制吸收累积的特性，饲用高粱对Cd的富集能力远大于Pb。研究结果将为利用饲用高粱修复重金属污染土壤提供理论依据。

关键词: 铅, 镉, 饲用高粱, 株高, 生物量, 富集