孔雀草 (Tagetes patula L.) 為臺灣常見的觀賞花卉植物，且為新發現的鎘超累積植物，具有環境適應力強、生質量大、和鎘累積量高的特性。本試驗建立孔雀草的水耕栽培系統，以探討氯化鎘處理下孔雀草的生理反應。試驗結果顯示孔雀草葉片在5 μM及10 μM氯化鎘處理14天後，鎘累積量可分別達到250和400 mg Cd kg-1，同時鮮重和乾重、葉綠素含量、根長與對照組都無顯著差異。若處理50 μM氯化鎘，則根部累積高達5363 mg Cd kg-1，同時孔雀草生長受到抑制，植株顯著矮小、鮮重乾重減少、葉綠素含量降低、malondialdehyde (MDA) 含量上升、根長縮短及根部細胞死亡。由切片結果可發現氯化鎘也會使孔雀草根部細胞產生皺縮、失水的現象。這些結果顯示在水耕系統中孔雀草至少能耐受10 μM氯化鎘逆境，同時地上部鎘累積量也超過鎘超累積植物之標準。

Tagetes patula, a popular garden species, is a newly discovered Cd
hyperaccumulator with the advantages of broad environmental adaptablilty, high biomass and high accumulating capability to Cd. To investigate the physiological changes to Cd, hydroponic culture system was developed. Expose of plants to 5 and 10 μM CdCl2 for 14 days results in accumulation of 250 and 400 mg Cd kg-1 Cd in leaves, respectively. Both 5 and 10 μM CdCl2 treatments did not show toxic effects on fresh weight, dry weight, chlorophyll content, and root length. In contrast, plants dramatically accumulated Cd with a maximum of 5363 mg Cd kg-1 after 14 days exposure at 50 μM CdCl2. The toxic effect caused by Cd was evident by the growth inhibition of root, chlorosis, increase of malondialdehyde (MDA) and root cell death. Moreover, cross sections of the root tissues revealed that Cd toxicity led to shrink and dehydrate phenotype of root tissues when plants were treated with 50 μM CdCl2. Taken together, T. patula is
tolerant to low concentration of Cd (10 μM) in the hydroponic system, and its accumulation of Cd is higher than the standard of hyperaccumulator in shoot tissue.