水体消落带重金属Cu和Cd在双穗雀稗与狗牙根植株中的迁移富集

Migration and Enrichment of Cu and Cd in Cynodon dactylon and Paspalum distichum Plants in Hydro-Fluctuation Belt

为了解水体消落带重金属胁迫处理下双穗雀稗和狗牙根的生长情况以及重金属在植株地上部和地下部的迁移富集情况,进行了不同浓度的外源重金属Cu2+和Cd2+的动态模拟试验。结果表明:狗牙根和双穗雀稗均能承受较高浓度的Cu胁迫,双穗雀稗比狗牙根能承受更高浓度的Cd胁迫;Cu在狗牙根中迁移富集量大于双穗雀稗,而Cd在双穗雀稗中的迁移富集量大于狗牙根;Cu和Cd胁迫时,两植物在不出现中毒现象的浓度范围内,富集量与胁迫离子浓度呈线性正相关,富集量均表现为地下部远大于地上部;Cu和Cd在狗牙根、双穗雀稗中的转运系数(TF)均小于1,不是Cu和Cd的超富集植物,但均能较好地修复铜、镉污染,是三峡库区消落带植被重建和Cu、Cd污染修复的优良物种。

The dynamic simulation test of exogenous Cu2＋ and Cd2＋ with different concentrations was conducted to study growth of C.dactylon and P .distichum under Cu2＋ and Cd2＋ stress,and migration and enrichment of Cu and Cd in over-ground and underground parts of C.dactylon and P .distichum. C.dactylon and P .distichum both have tolerance to Cu with higher concentration and Cu tolerant capacity of P .distichum is higher than C.dactylon.Cu migration and enrichment of C.dactylon is higher than P .distichum but Cd migration and enrichment of P .distichum is higher than C.dactylon.There is a linear positive correlation between Cu and Cd enrichment in two plants and their concentration under Cu and Cd concentration without intoxicating phenomenon in two plants, and their enrichment in the underground is higher than the over-ground.The transfer coefficient of Cu and Cd in C.dactylon and P .distichum is less than 1,which indicates that two plants are not Cu and Cd super-enrichment plants but two plants have the good repair capacity of Cu and Cd pollution.Therefore,C.dactylon and P .distichum are good species for revegetation of water hydro-fluctuation belt and restoration of Cu and Cd pollution in Three Gorges Reservoir.