多金属硫化物矿区不同品种水稻根际土壤酶活的变化

选取酸性矿山废水污灌形成的多重金属污染水稻土，采用多格层根际箱模拟水稻根际环境，研究高镉积累水稻长香谷fOryzasativaL．cv．Choukoukoku）和低镉积累水稻金农丝苗（OryzasativaL．cv．Jinnongsimiao）2个品种水稻生育中后期（分蘖期、孕穗期、扬花期、蜡熟期）根际土壤脲酶、酸性磷酸酶和过氧化氢酶活性的变化特征。结果表明：高镉积累水稻比低镉积累水稻各时期根际土壤脲酶活性低，随着生育期的延长，2个品种水稻土壤脲酶活性先降低后升高（分蘖期酶活性最高），2种水稻土壤脲酶活性均在根际s0层达到最高，但其他各层土壤脲酶活性与根系距离无显著关系。随着水稻生育期的延长，高镉积累水稻根际土壤酸性磷酸酶活性先升高（在孕穗期酶活性达最高），随后降低；低镉积累水稻土壤酸性磷酸酶活性则在分蘖期最高，之后逐渐降低。除分蘖期高镉积累水稻土壤酸性磷酸酶活性低于低镉积累水稻酶活性外，其他2个时期前者酸性磷酸酶酶活性均高于后者的酶活。2个品种水稻土壤过氧化氢酶活性随生育期延长不断升高，在整个生育后期，高镉吸收水稻比低镉吸收水稻各时期土壤过氧化氢酶活性高，但在蜡熟期时两者无显著差异；在各时期2种水稻过氧化氢酶活性在根系S0层达到最大，随着与水稻根系距离的增加呈先降低后增加的趋势。可见，在多重金属污染矿区，土壤酶活性明显受水稻品种、水稻生长时期和水稻根系的影响。该结果可以为研究多重金属污染矿区分析土壤酶活性与不同重金属积累程度的水稻品种作物相关关系提供数据支持，给农业生产及土壤修复提供依据。

Rhizosphere effect of soil enzymes under different rice varieties grown in AMD polluted paddy soil

To compare the difference of soil biological characteristics between rice Oryza sativa L. cv. Choukoukoku （OSC） and Oryza sativa L. cv. Jinnongsimiao（OSJ） that has a high and low absorption capacity of cadmium, respectively, the changes of urease, acid phosphatase and hydrogen peroxidase activities in rhizosphere soil of two rice varieties at four growth stages （tillering stage, booting stage, flowering stage and milk ripe stage） were investigated by using multiple lattice layer rhizobox system. The soil samples were taken from the multi-metal contaminated paddy soils due to the irrigation of acid mine drainage for more than 40 years. The results showed that the urease activity of OSC was lower than that of OSJ in the whole growth period. The highest urease activity in rhizosphere soil of two rice varieties was at tillering stage and in the root compartment （SO）, then decreased with plant growth to reach the minimum at booting stage and increased thereafter till milk ripe stage. The soil urease activity of two rice varieties had no significant relationship with root distance in root compartments （S1, $2, $3, $4, $5, B）. The soil acid phosphatase activity of OSC increased with plant growth and was highest at booting stage and decreased till milk ripe stage, however, the soil acid phosphatase activity of OSJ reached the maximum at tillering stage and then decreased gradually. The acid phosphatase activity of OSC was higher than that of OSJ at flowering stage and milk ripe stage except tillering stage. The soil hydrogen peroxidase activity of two rice varieties increased with plant growth and the soil hydrogen peroxidase activity of OSC was higher than that of OSJ throughout the period except milk ripe stage. In addition, the soil hydrogen peroxidase activity of two rice varieties was higher in root compartments （SO and B） than in middle root compartments （S1, $2, $3, $4, $5）, which was highest in root compartment （SO） Our results indicated that enzyme activities of rhizophere soil were remarkably affected by rice varieties, rice growth period and rice root system in multi-metal contaminated mining area. The results provide not only basic data for analyzing the correlationship between soil enzymes in multi-metal contaminated mining area and rice varieties that have different heavy metal accumulating abilities, but also evidence for agricultural production and soil restoration.