大豆连作的过氧化氢酶活性与根系分泌物

Hydrogen Peroxide Enzyme Activity and Roots Exudations in Soybean Contiuous Cropping

摘要:

本文通过试验对大豆连作胁迫下土壤中过氧化氢酶活性进行了研究，结果表明，过氧化氢酶活性下降幅度很大，连作3年酶活性下降21.4%。过氧化氢酶活性的明显下降，使其解毒能力减弱，从而导致土壤中过氧化氢的积累，对大豆根系毒害作用加重。由于根系受毒害作用，使根系吸收养分受阻，在营养胁迫下，又使根系分泌物的种类和数量都发生改变。反过来，又抑制了土壤中酶活性。为此，我们认为这是连作胁迫条件下产生的生化互作效应（Allelopathy），也是连作下产生生物障碍的主要原因。

Abstract:

Hydrogen Peroxide enzyme activity of soil under soybean continuous cropping stress was investigated by experiments. The results showed that hydrogen peroxide enzyme activity trooped significantly and it was reduced by 21.4% in soybean following soybean cropping for three years. Hydrogen peroxide accumulate in soil and aggravate poison to soybean roots as hydrogen peroxide enzyme activity drop obviously. The varinties and amount of roots exudations will change because nutrient elements uptake is obstructed by hydrogen peroxide poison to roots. In turn, it will inhibit soil enzyme activities.Therefore we think this is a kind of allelopathy under monocropping stress and a main reason of biological barriers caused by soybean continuous cropping.