通过水培实验,研究了不同水平亚硫酸钠、腐植酸对李氏禾植株生长、铬吸收积累和营养液中铬含量的影响。亚硫酸钠和腐植酸能明显提高李氏禾对铬的吸收和富集能力。与对照相比,50 mg/L亚硫酸钠处理能显著提高李氏禾根、茎、叶中铬含量和积累量;10 mg/L腐植酸处理能显著提高李氏禾根、茎、叶中铬含量和积累量。亚硫酸钠和腐植酸能明显提高转运系数,促进铬从李氏禾根向地上部分的转移。50 mg/L亚硫酸钠和5 mg/L腐植酸处理下,转运系数大于1,地上部铬含量显著高于根中铬含量。亚硫酸钠显著提高营养液中Eh值,对pH值的影响不明显,李氏禾对铬的吸收以Cr(III)为主。
A hydroponic experiment was conducted to study the effect of sodium sulfite and humic acid on the growth and Cr accumulation of Leersia hexandra Swartz,as well as the Cr concnetration in the nutrient solution. Sodium sulfite and humic acid could improve the Cr accumulation ability of L. hexandra. Compared to the control,the treatments of 50 mg/L sodium sulfite and 10 mg/L humic acid significantly improved the Cr extraction amounts and accumulation in the root,stem and leaf of L. hexandra. Sodium sulfite and humic acid could obviously increase the translocation factor,and promote the translocation of Cr from plant root to shoot. The translocation factor of L. hexandra in the treatments of 50 mg/L sodium sulfite and 5 mg/L humic acid were greater than 1,and the concentration of Cr in plant shoot was higher than root. Sodium sulfite significantly increased the Eh value,while had no influence on the pH value in the nutrient solution. Meanwhile,Cr( III) was the main asortption form in L. hexandra.