2种生态型三叶鬼针草的不同株数混种比例对其镉累积的影响

Effects of Interplantation Ratio of Two Ecotypes of Bidens pilosa on Cadmium Accumulation

为研究不同混种比例对2种生态型三叶鬼针草(Bidens pilosa)镉积累的影响,通过盆栽试验研究了镉污染条件下(w为10 mg·kg-1)农田生态型与矿山生态型三叶鬼针草在混种株数比例为1∶4、2∶3、3∶2、4∶1以及单种时2种生态型三叶鬼针草对镉的积累效果。结果表明,混种提高了农田生态型三叶鬼针草单株生物量,但降低了矿山生态型三叶鬼针草单株生物量。混种也提高了2种生态型三叶鬼针草的叶绿素a、叶绿素b及类胡萝卜素含量。此外,混种显著提高了2种生态型三叶鬼针草各器官的镉含量(P<0.05)。当农田生态型与矿山生态型混种株数比例为2∶3时,2种生态型三叶鬼针草各器官镉含量均最大,且单盆三叶鬼针草地上部分及整株镉积累量也最大,分别为422.08和477.91μg·盆-1。因此,农田生态型与矿山生态型三叶鬼针草混种株数比例为2∶3时能有效提高2种生态型三叶鬼针草对镉的积累能力,增强对镉污染土壤的修复效果。

To study effects of interplantation ratio on cadmium accumulation of two ecotypes ( farmland and mining) of Bi?dens pilosa, a pot experiment, designed to have six treatments in ratio, i.e. 1 ∶ 4, 2 ∶ 3, 3 ∶ 2, 4 ∶ 1, farmland ecotype only and mining ecotype only, and the soil spiked with 10 mg·kg-1 cadmium, was conducted. Results demonstrate that as compared with their respective treatments of monoculture interplantation increased the farmland ecotype of B. pilosa bio?mass, but decreased the mining ecotype of B. pilosa in biomass per plant, and significantly increased the contents of chlo?rophyll a, chlorophyll b and carotenoid in the two ecotypes of B. pilosa, and the concentration of cadmium in various or?gans of the two ecotypes of B. pilosa. When the interplantation ratio was 2 ∶ 3 (farmland ecotype ∶ mining ecotype),the content of cadmium was the highest in all organs of the two ecotypes of B. pilosa, and the cadmium accumulation in the shoots and the whole plant in one pot were also the highest, reaching up to 422?08 and 477?91 μg·pot-1 , respectively. To sum up, the interplantation of the two ecotypes of B. pilosa at a ratio of 2 ∶ 3 ( farmland ecotype ∶ mining ecotype) may effectively improve the plants′cadmium accumulation capacity, and consequently the effect of the two ecotypes of B. pilosa remedying cadmium contaminated soils.