Abstract: 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.

Key words: rice, seed, microbial diversity, nonpathogenic bacteria, Pseudomonas spp., non Pseudomonas spp., biological control

摘要： 1997～1999年，分别从中国长江三角洲稻区的276份和日本稻区30份水稻种子样本中分离出3 200余个及303个非致病菌株。经细菌学、菌落形态及致病性测定后，对386个格兰氏阴性菌及30个阳性菌进行Biolog鉴定，并用3个水稻病原菌进行了拮抗性筛选。从中国的水稻种子中测得假单胞杆菌属的10个种及5个非假单胞杆菌属中的14个种；从日本的水稻种子中测得假单胞杆菌属的6个种及5个非假单胞杆菌属中的10个种。这5个非假单胞菌属中的14个种尚未有从中国稻谷上分离出来的记录。从中国的14个细菌种及日本的10个细菌种中测得拮抗菌，其中占拮抗细菌种总数64%的种来自假单胞杆菌属和芽孢杆菌属。

关键词: 水稻, 种子, 细菌多样性, 非致病细菌, 假单胞杆菌种, 非假单胞杆菌种, 生物防治