PCR-DGGE Analysis of Nematode Diversity in Cu-Contaminated Soil*1

A wheat pot experiment was conducted under greenhouse conditions to assess the effect of copper contamination on soil nematode diversity by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) method and morphological analysis. The soil was treated with CuSO4·5H2O at the following concentrations: 0, 50, 100, 200, 400, and 800 mg kg−1 dry soil, and the soil samples were collected at wheat jointing and ripening stages. Nematode diversity index (H′) from morphological analysis showed no difference between the control and the treated samples in either of the sampling dates. At the wheat ripening stage, nematode diversity obtained by the PCR-DGGE method decreased noticeably in the Cu800 treatment in comparison with the control. With optimization of the method of nematode DNA extraction, PCR-DGGE could give more information on nematode genera, and the intensity of the bands could reflect the abundance of nematode genera in the assemblage. The PCR-DGGE method proved promising in distinguishing nematode diversity in heavy metal contaminated soil.