高氯酸盐与铅复合污染对8种空心菜幼苗生长的影响

通过室内滤纸法试验研究发现,Cl O-4、Pb及其复合污染对8个品种空心菜(Ipomoea aquatica Forsskal)幼苗根长、芽长以及鲜重的影响总体呈现出低浓度促进、高浓度抑制的规律,对空心菜幼苗根部的抑制效果最为明显,其中泰国空心菜和香港纯白大叶空心菜在Cl O-4和Pb复合污染下的根长分别仅为对照组的31.66%和38.64%。Cl O-4和Pb复合污染对空心菜的抑制效果因空心菜品种、污染物的类型、浓度及其组合的不同而不同,且呈现出复杂的交互作用,多数空心菜品种在低浓度(1 mg·L-1的Cl O-4+5 mg·L-1的Pb)和中浓度(20 mg·L-1的Cl O-4+50 mg·L-1的Pb)的复合条件下的交互作用类型表现为协同作用,而在高浓度(200 mg·L-1的Cl O-4+500 mg·L-1的Pb)的复合条件下则主要表现为拮抗作用。空心菜对Cl O-4、Pb及其复合污染的耐性都存在明显的品种差异,其中耐性较强的品种是泰国柳叶空心菜、港种青绿梗竹叶空心菜和金龙白骨柳叶空心菜,耐性较差的品种是泰国空心菜和香港纯白大叶空心菜。

Combined Effects of Perchlorate and Lead on Seedling Growth of Eight Ipomoea aquatica Forsskal Varieties

Perchloratte(ClO₄^-) and lead(Pb) are both inorganic contaminants in soils. However, their interactive effects on plants have not been well investigated. Here the root length, shoot length and biomass of 8 Ipomoea aquatica Forsskal varieties were examined under different rates of ClO₄^- and Pb and their combinations. Results showed that increasing ClO₄^-, Pb, and ClO₄^- +Pb concentrations increased inhibitory effects on the root length, shoot length and fresh weight of I. aquatica seedlings, with the most obvious inhibition found in the root length, in which a significant dose-effect relationship(P<0.05) was present. Different varieties of I. aquatica responded differently to ClO₄^- and Pb. The root lengths of Thailand and wide-leaf white skin(Hong Kong) I. aquatica were only 31.66% and 38.64% of that of the controls. The interaction of ClO₄^- and Pb showed synergism for most varieties of I. aquatica at low concentrations, but antagonism at higher concentrations. The narrow-leaf(Thailand), narrow-leaf green-skin(Hong Kong) and narrow-leaf white-skin I. aquatica were relatively tolerant to, whereas the Thailand and wide-leaf white-skin(Hong Kong) varieties were susceptible to perchlorate and lead stresses.