丛枝菌根真菌对旱稻根际Pb形态分布的影响

The Effects of Arbuscular Mycorrhizal Fungi(AMF) on Forms of Pb in the Upland Rice Rhizosphere under Different Pb Levels

为了研究丛枝菌根真菌对旱稻根际土壤中重金属铅(Pb)化学赋存形态的影响,采用盆栽实验的方法,研究了不同Pb处理水平(0、300、600mg/kg)下,接种丛枝菌根真菌(AMF)Glomus mosseae对旱稻(Oryzal sativa L.)根际Pb形态分布的影响。结果表明,接种处理下,旱稻根系侵染率以及根外菌丝量随着土壤Pb含量增加而显著降低(P<0.05)。与未接种处理相比,接种处理显著提高Pb处理下根际pH;300mg/kg Pb处理下,接种显著增加土壤球囊霉素含量,600mg/kg Pb处理下,接种处理显著降低土壤球囊霉素含量(P<0.05);在Pb处理下,与未接种处理相比,接种处理显著提高可交换态Pb含量,显著降低了碳酸盐结合态以及铁锰氧化物结合态Pb含量,却显著增加了土壤中有机质结合态Pb含量(P<0.05)。这说明接种丛枝菌根真菌可以改变旱稻根际土壤中Pb的形态分布。

In order to study the effects of arbuscular mycorrhizal fungi on the soil Pb distributional pattern in the upland rice（Oryzal sativa L.） rhizosphere,pot culture was conducted to investigate the effects of AMF-Glomus mosseae on the change of Pb forms under different Pb levels including 0,300,600 mg/kg soil.The results indicated that,the root colonization and hyphae length decreased by the root colonization of Glomus mosseae with increasing soil Pb concentration.Compared with non-mycorrhizal plants,the mycorrhizal colonization increased rhizospheric soil pH under both Pb treatments.The mycorrhizal colonization enhanced the soil gomalin concentration under 300 mg/kg soil Pb treatments,yet it decreased under 600 mg/kg soil Pb treatments.In rhizosphere of AM upland rice,exchangeable Pb and the amounts of Pb bound to organic matter increased significantly yet the amounts of Pb bound to carbonates and to iron and manganese oxides decreased significantly compared with that of non-mycorrhizal plants.It suggested that,the soil Pb distribution pattern in the upland rice rhizosphere could be changed by the colonization of Glomus mosseae.