Impact of transgenic AFPCHI (Cucumis melo L. Silver Light) fungal resistance melon on soil microbial communities and enzyme activities

A greenhouse experiment was conducted for evaluation of ecological effects of transgenic melon plants in the rhizospheric soil in terms of soil properties, enzyme activities and microbial communities. Organic matter content of soil under transgenic melon plants was significantly higher than that of soil with non-transgenic melon plants. Significant variations were observed in organic matter, total P and K in soil cultivation with transgenic melon plants. There were also significant variations in the total numbers of colony forming units of fungi, actinomycetes and bacteria between soils treated with transgenic and non-transgenic melon plants. Transgenic and non-transgenic melon significantly enhanced several enzymes activities including urease, acid phosphatase, alkalin phosphatase, arysulphtase, β glucosidase, dehydrogenase, protease and catalase. Soil polyphenoloxidase activity of T1 transgenic melon was lower than that of T0 transgenic melon and a non-melon plant during the same period. The first generation transgenic melon plants (T0) showed significantly greater (p<0.05) effect on the activitiy of arylsulfatase, which increased from 2.540x106 CFU g-1 (control) to 19.860x106 CFU g-1 (T0). These results clearly indicated that transgenic melon might change microbial communities, enzyme activities and soil chemical properties.