The results of rice inoculation experiment in a spermosphere model system with various nitrogen - fixing bacteria suspensions showed that the strain w12 represent highest ara amongst all the strains tested , the differences between it and the other 44 strains were highly significant . moreover , the high ara of the strain w12 associated with different rice genotypes were less varied 通过比较多个菌株与同一水稻基因型的联合固氮效率及w12与不同基因型的水稻的联合固氮效率,发现供试菌株中w12与水稻的联合固氮效率最高,且远远高于其它菌株;同时这种高的固氮效率在不同的水稻基因型之间没有表现出显著差异。