煤基腐殖酸对外源砷胁迫下玉米生长及生理性状的影响简

为了筛选用于砷污染土壤治理的煤基腐殖酸，采用盆栽实验研究了施用不同种类和浓度的煤基腐殖酸及EDTA对外源砷胁迫下玉米株高、株鲜重、株干重、根干重、砷积累量、叶片抗氧化酶（POD，SOD和CAT）活性和脯氨酸含量的影响。结果表明，11种供试煤基腐殖酸均促进了玉米生长，提高了叶片POD、SOD和CAT活性。其中6和10号腐殖酸可降低土壤砷活性和显著抑制玉米吸收和积累砷，而8和9号腐殖酸增加了土壤活性砷和显著促进了玉米对砷的吸收和累积，且不同程度地强于EDTA。除8和9号外，其余腐殖酸均可明显降低玉米叶片脯氨酸的含量。EDTA可显著促进玉米吸收和积累砷，且加剧了砷对玉米的危害。因此，8和9号供试煤基腐殖酸可以替代EDTA活化土壤砷，与植物配合以提高砷污染土壤的植物修复速度和效果，而6和10号供试煤基腐殖酸则可用于土壤砷钝化剂，以保证作物产品的安全。

Effects of coal-based humic acids on growth and some physiological characters of maize stressed by exogenous arsenic

In order to select coal-based humic acids for strengthening the phytoremediation of As-polluted soil, a pot experiment was conducted to study the effects of different kinds and concentrations of coal based humic acids and EDTA on the plant height, shoot fresh weight, shoot dry weight, root dry weight, arsenic accumulation, antioxidant enzymes (POD, SOD and CAT) activities, proline contents of maize (Zea Mays) stressed by exogenous arsenic. The results showed that 11 kinds of experimental coal-based humic acids all promoted the growth of maize and increased the POD, SOD, and CAT activities in leaves at various degrees. The No. 6 and 10 humic acids decreased the As activity of soil and significantly inhibited the absorption and accumulation of maize to arsenic, but the No. 8 and 9 humic acids increased the As activity of soil and significantly promoted the absorption and accumulation of maize to arsenic and stronger than EDTA at various degrees. All experimental hunic acids significantly reduced the contents of proline in leaves of maize except No. 8 and 9 hunic acids. EDTA significantly increased the absorption and accumulation of maize to arsenic and aggravated the damage of arsenic stress to maize. Therefore, the No.8 and 9 coal-based humic acids may replace EDTA as activators for increasing the activity of arsenic in soils and increase the speed and effect of phytoremediation of As-contaminated soils coordinating with plants, while the No. 6 and 10 coal-based humic acids may be used as inhibitors of soil arsenic for ensuring the safety of crop products.