根系互作对玉米与续断菊铅镉累积的影响及其效应分析

Analysis of the Effect of Root Interaction on Sonchus asper L.Hill. and Maize for Pb/Cd Accumulation

通过单作(PVC塑料隔板分隔)、隔根(尼龙网分隔)、间作(不分隔)3种处理方法研究玉米、续断菊不同互作方式对Pb、Cd吸收的影响,并对根系效应进行了分析。结果表明:(1)3个处理中玉米生物量隔根相比单作增加了74.32%,间作相比单作减少了15.57%;续断菊生物量间作比单作增加了78.29%,隔根比单作增加了16.45%。(2)玉米Pb含量间作比较单作降低了27.4%,隔根相比单作降低了15.10%;玉米Cd含量隔根显著高于单作和间作,分别高出16.62%和14.11%,单作与间作之间无显著性差异。(3)续断菊Pb含量间作显著低于单作与隔根,分别低29.73%和23.68%,隔根与单作之间差异性不显著;续断菊Cd含量间作显著高于单作和隔根,分别高出38.97%和38.65%,单作与隔根之间差异性不显著。(4)3种处理中,与单作玉米Pb累积量比较,间作降低了37.68%,隔根增加了53.27%;续断菊Pb累积量间作比单作增加了170.21%,隔根比单作增加了48.47%。3个处理中,玉米Cd累积量间作比单作降低了44.32%,隔根比单作增加了98.86%;续断菊Cd累积量间作比单作增加145.90%,隔根与单作之间没有显著性差异。(5)3个处理中玉米Pb有效转运系数间作<单作<隔根;玉米Cd有效转运系数间作<单作<隔根。3个处理中续断菊Pb有效转运系数间作>单作>隔根;续断菊Cd有效转运系数间作>单作>隔根。(6)根系互作总效应抑制了玉米对Pb、Cd的吸收,其中根系效应抑制了玉米对Pb、Cd的吸收,溶液菌根效应促进了玉米对Cd的吸收;根系互作总效应促进了续断菊对Pb、Cd的吸收,其中,根系效应抑制了续断菊对Pb的吸收累积,促进了续断菊对Cd的吸收累积,溶液和菌丝效应促进了续断菊对Pb的吸收累积,抑制了续断菊对Cd的吸收累积。结果表明,根系作用降低了玉米Pd、Cd累积量,提高了续断菊Pb、Cd累积量。

The influence of absorption accumulation of Pb and Cd as well as the rhizosphere effects between maize and compositae under different interactions by three different ways including monoculture（PVC board separated）, root separation（nylon net separated） and intercropping（no separated） was analyzed. Results indicated that： compared with monoculture, the biomass of maize′s root separation increased by 74.32% while there was an increase of 16.45% in compositae＇s;the intercropping of maize declined by 15.57% while the compositae′s droped by 15.10%. There was a decrease of Pb content and root separation of maize compared with monoculture, by 27.4% and 15.10% respectively. The Cd content in maize root separation was 16.62% up on monoculutre and 14.11% up on intercropping while there was no remarkable difference between monoculture and intercropping. The Pb content of compositae by the means of intercropping is significantly lower than that by the means of monoculture（29.73% lower） and root separation（23.68% lower）, while there is no remarkably difference between monoculture and root separation. The Cd content of compositae by the means of intercropping is noticeably higher than that by the means of monoculture（38.97% higher） and root separation（38.65% higher）, while there is no remarkably difference between monoculture and root separation. Among three treatments, compared with Pb cumulant of monoculture maize, the inter-cropping reduced by 37.68%, and the separating root increased by 53.27%. The intercropping of Pb cumulant of compositae increased by 170.21%than that of monoculture,and the separating root increased by 48.47%than monoculture.Among three treatments,the intercropping of maize Cd cumulant reduced by 44.32%than that of monoculture,and the separating root increased by 98.86%than that of monoculture.The intercropping of Pb cumulant of compositae increased by 145.90%than that of monoculture,and there is no significant difference between separating root and monoculture.Among three treatment,for the effective transfer coefficient of maize Pb,intercroppingmonocultureseparating root;for the effective transfer coefficient of maize Cd,intercroppingmonocultureseparating root.Among three treatments,for the effective transfer coefficient of compositae Pb,intercroppingmonocultureseparating root.For the effective transfer coefficient of compositae Cd,intercroppingmonocultureseparating root.The total effect of interspecific root interactions inhibited the corn from absorbing Pb and Cd,and among them,the root system effect inhibited the corn from absorbing Pb and Cd,and the mycorrhizal effect promoted the maize to absorb Cd.The total effect of interspecific root interactions promoted the compositae to absorb Pb and Cd,and among them,the effect of root system inhibited the compositae from absorbing and accumulating Pb,promoted the compositae to absorb and accumulate Cd,the solution and hyphae effect promoted the compositae to absorb and accumulate Pb,but inhibited the compositae from absorbing and accumulating Cd.Results indicate that the root system effect reduced the maize′s accumulation amount of Pd and Cd,but improve the compositae′s accumulation amount of Pb and Cd.