Abstract: The PCR-based RISA, DGGE, and 2D-PAGE were adopted to analyze the bacterial diversity in rhizosphere soil of soybean. Most abundant soil bacterial diversity was acquired by 2D-PAGE (gene spots), followed by DGGE (gene bands), and by RISA (gene bands). The RISA gave the fewest bands, but the result was more stable and the experimental operation was more easy; DGGE obtained more bands and showed good precision, but had more error  sources; while 2D-PAGE as a novel soil microbial research method could overcome the low-resolution problem of the other two methods, achieve abundant information of soil bacterial diversity, and play an important role in the research of soil microbial ecology. However, the operation of 2D-PAGE was more complicated and required strict conditions, compared with RISA and DGGE. In spite of these disadvantages, 2D-PAGE had shown pote ntial advantages in the research field of soil microbial ecology.

Key words: Alexandrium tamarense, Red tide, Nitrogen, Phosphorus, Specific growth rate