不同镉处理对两种生态型水蜈蚣镉富集特性的影响

采用室内盆栽试验，研究了在不同浓度cd处理下，两种生态型水蜈蚣的生长和对cd的吸收和富集特性。结果表明：（1）在2mg·kg^-1Cd处理时，Cd对两种生态型水蜈蚣生物量的影响较小。之后随着cd处理浓度的增加，两种生态型水蜈蚣生物量均呈降低的趋势，且差异显著。在200mg·kg^-1Cd处理时，矿山生态型水蜈蚣死亡，而非矿山生态型仍能维持一定生长，表现出较强的cd耐性。（2）在高浓度cd处理下，非矿山生态型水蜈蚣比矿山生态型具有更强的Cd富集能力。在2、10、50mg·kg^-1Cd处理时，两种生态型水蜈蚣Cd含量和积累量均呈增加的趋势。在200mg·kg^-1Cd处理时，非矿山生态型水蜈蚣地上部和地下部Cd含量分别达到498．66mg·kg^-1和1016．09mg·kg^-1，积累量分别为86．00μg·pot^-1和123．82μg·pot^-1，具有较强的cd富集能力。（3）在不同浓度Cd处理下，两种生态型水蜈蚣地上部富集系数均大于1，表现出较强的cd富集能力；矿山生态型水蜈蚣转移系数最大值为0．55，非矿山生态型为0．53。两种生态型水蜈蚣对cd均有一定的富集特性，而在高浓度Cd处理时非矿山生态型水蜈蚣的cd富集能力更强。

Effect of Cadmium on Accumulation Characteristics of Cadmium in the Two Ecotypes of Kyllinga brevifolia Rottb

Kyllinga brevifolia Rottb, a perennial herb, is reported to accumulate Pb from soil. However, little is known about its ability to accumulate cadmium（Cd ） from soil. Here we examined the plant growth and Cd accumulation of two ecotypes of K. brevifolia Rottb（mining ecotype-ME and non-mining ecotype-NME） grown at different levels of Cd for 60 days using a pot experiment. The biomass of two eeotypes was not affected by 2 mg·kg^-1 Cd treatment, while it decreased significantly at higher Cd concentrations. At 200 mg·kg^-1, the ME plants died, whereas the NME still grew, showing a higher Cd tolerance than ME. The Cd concentrations and accumulation of K. brevifolia Rottb increased with soil Cd. Exposed to 200mg·kg^-1, the NME contained 498.66mg·kg^-1 and 1 016.09mg·kg^-1 Cd, and accumulated 80.00μg·pot^-1 and 123.82 μg·pot^-1 Cd in the shoots and roots, respectively. The Cd bioaccumulation coefficient of two ecotypes of K. brevifolia Rottb was greater than 1, indicating their Cd enrichment ability. The maximum translocation factor was 0.55 and 0.53 for the ME and NME, respectively. The results show that two ecotypes ofK. brevifolia Rottb have ability to tolerate and accumulate Cd, with the NME showing better performance in higher Cd soils.