续断菊与玉米间作对作物吸收积累镉的影响

Absorption and Accumulation of Cd by Sonchus asper L.Hill.and Maize in Intercropping Systems

通过盆栽试验,研究了不同镉浓度(0、50、100、200mg·kg-1)对续断菊(SonchusasperL.Hill)和玉米间作条件下两种植物镉吸收积累的影响。结果表明:与单作续断菊和玉米相比,间作使续断菊生物量提高了4.8%～64.9%,玉米生物量提高了4%～33%,间作续断菊体内镉含量较单作提高了31.4%～79.7%(100mg·kg-1镉处理除外)。与单作相比,在土壤镉含量为50～200mg·kg-1内,间作使玉米体内镉含量降低了18.9%～49.6%。单作时,续断菊地上部和根部镉含量都与土壤可溶态镉含量显著正相关(P<0.05),相关系数分别为0.962和0.976;间作条件下,玉米根、茎、叶中镉含量均与土壤可溶态镉含量显著正相关(P<0.05),相关系数分别为0.991、0.959和0.977。除对照外,间作使玉米镉有效转运系数降低,三个镉浓度下分别比单作降低了21%、71%和25%。不论是单作还是间作,续断菊镉转运系数都高于玉米。研究结果表明,续断菊和玉米间作促进了续断菊对土壤中镉的吸收和积累,同时抑制了玉米体内镉的积累量。

Pot experiments were carried out to study the effects of cadmium levels（0,50,100 and 200 mg·kg-1）on the Cd absorption and accumulation of Sonchus asper L.Hill and maize（Zea mays L.）under intercropping system.The results showed that biomass of S.asper and maize increased by 4.8%～64.9% and 4%～33% under intercropping system comparing with monoculture system,respectively.Cd contents of S.asper increased by 31.4%～79.7% under intercropping,except for decreased by 5.6% when soil Cd content was 100 mg·kg-1.Cd content in maize decreased by 18.9%～49.6% under intercropping system when Cd content in the soil ranged from 50 to 200 mg·kg-1.Significantly positive correlations between Cd contents in shoot and root and soil available Cd content were observed with correlation coefficients 0.962（P0.05）and 0.976（P0.05）under monoculture system,respectively.Significantly positive correlations between Cd contents in root,stem and leaf and soil available Cd were observed with correlation coefficients 0.991（P0.01）,0.959（P0.05）and 0.977（P0.05）under intercropping system,respectively.The effective transfer coefficient of Cd in maize was reduced by 21%～71% under intercropping system when soil Cd content ranging from 50 to 200 mg·kg-1.Under both monoculture and intercropping systems,Cd effective transfer coefficient of S.asper was higher than that of maize.The results indicate that uptake and accumulation of Cd in S.asper under intercropping system could be promoted and content of Cd in maize could be reduced.