Abstract: The communities (quantity effects) of endophytic prokaryotes in transgenic and wild-type rice were investigated in the present study. At first, the optimal sterilizing methods for the surface of leaves, stems and roots of rice were investigated and determined as follows: rice roots and the other tissues (stems and leaves) could be sterilized through soaking in 70% ethanol for 7 min and 2 min, respectively; both ethanol-soaking were followed by washing with distilled water twice. Thereafter, the number of endophytic prokaryotes in the roots, stems and leaves of rice was examined, and the results showed that the number of endophytic prokaryotes in all parts of transgenic rice was less than that of wild-type rice at the seedling stage; the similar results were also observed at the stooling stage, except that in the leaves of transgenic rice TT51-1. The number of endophytic prokaryotes in all parts of rice at stooling stage was higher than that at seedling stage for both transgenic and wild\|type rice. Our data showed that Bt gene insertion could significantly affect on the number of endophytic prokaryotes of rices in both of seedling and stooling stages．

Key words: endophytic microorganisms, surface sterilization, transgenic, prokaryotes