Abstract:

Phytoremediation is a method of clearing up pollutants from environment by plants. It has the advantages of low cost, saving land resources and no secondary pollution. More importantly, it does not destroy the ecological environment. So it has a bright future for apply phytoremediation in cleaning the contaminated soil. Atrazine is a herbicide that is widely used in China. Poplar (Populus deltoids cv. I 69-55) and transgenic poplar (Populus deltoides × nigra, DN34) in pots were used to test if they remediate atrazine contaminated soil in a greenhouse in this study. The degradation dynamic of atrazine was studied in different rhizosphere environment with GC method; the dynamic variation of microbe was investigated to elucidate the rhizosphere effects and mechanism of phytoremediation of Atrazine contaminated soil by transgenic poplar, in the process of phytoremediation. The main results were summarized as follows: 1) There was no significant difference in atrazine (the applied concentration was 10 mg·kg^-1 in the soil of pots) between the ordinary poplar rhizosphere soil and the nonrhizosphere soil. However transgenic poplar was able to clean up atrazine. There was significant difference in atrazine between the transgenic poplar rhizosphere soil and the nonrhizosphere soil. 2) The bacteria in nonrhizosphere soil were significantly inhibited by 10 mg·kg^-1 atrazine. The number of bacteria, fungi and actinomycosis in rhizosphere soil was more than that in nonrhizosphere soil. The number of bacteria in transgenic poplar rhizosphere soil remained stable, and was generally more than that in other rhizosphere soil. The number of actinomycosis was in an order: noncontaminated soil ＞rhizosphere soil contaminated with atrazine＞nonrhizosphere soil contaminated with atrazine.

Key words: atrazine, phytoremediation, poplar, degradation, microbe