Comparison of Microbial Diversity of Nonpathogenic Bacteria from Rice Seeds in Yangtze Delta Area, China and Japan

During 1997-1999, more than 3200 nonpathogenic bacterial isolates were isolated from 276 rice seed samples in Yangtze Delta area, China and 303 isolates from 30 samples in Japan. After basic bacteriology, colony morphology and pathogenicity test, 386 representative Gram negative and 30 Gram positive bacteria were selected for Biolog test and used for evaluation of antagonists against three major pathogens of rice. Ten species or types of Pseudomonas were detected from rice seeds in China and six species in Japan. Fifteen and 13 species of non Pseudomonas were found in China and Japan, respectively. All the species of the non Pseudomonas were first reported from rice seeds in China. Fourteen and ten bacterial species of five genera were involved in the antagonists in Yangtze Delta area, China and Japan, respectively. About 64% of the total bacterial species having antagonists were from genus Pseudomonas and Bacillus. 