THE DIVERSITY OF DOMINANT SOYBEAN RHIZOBIUM TYPE IN CHINESE SOILS AND ITS SYMBIOTIC CHARACTERISTIC WTIH HOST

The applying of soybean rhizobium inoculation were usually not success in Chinese soybean field. Our results indicated that serogroup 2048, USDA217. DE1611, 2120. 2077 and DH444, USDA110, LL120, 005, C224 were dominant rhizobium population in the South, North and Yellow River Valley of China. These dominant indigenous isolates accounted for 60.3-81.6% of total isolates of per site tested. Each of soil tested in soybean production region contained 104 cell of soybean rhizobium per gram. Several pot-culture experiments showed the diversity of nodulating. N2-fixing effectiveness of strain with soybean cultivar. Most of indigenous strains were relatively low or medium-efficiency fixer in contrast with B.Japonicum 113-2. Therefore, it will be our subsequent object to select and breed soybean genotype that can resist nodulation of indigenous strains and rhizobium that can compete nodulation against indigenous strains.