Division of Plant Industry and Division of Water and Land Resources, Commonwealth Scientific and Industrial Research Organisation, Canberra, A.C.T. 2601, Australia.
Appl Environ Microbiol. 1988 Jul;54(7):1825-30. doi: 10.1128/aem.54.7.1825-1830.1988.
Antigenic relationships among seven strains of Bradyrhizobium japonicum were examined by immunodiffusion reactions, in which cells of each strain were reacted against each of the seven corresponding antisera. Similar analyses were performed with Rhizobium trifolii (28 strains), Rhizobium meliloti (9 strains), and rhizobia of the cowpea miscellany (13 strains). Antigens and antisera were reacted within each species only; serological interspecies cross-reactions were not performed. The results, scored qualitatively as reactions of identity, cross-reactions, or no reaction, were formed into datum matrices and used to analyze the relationships between strains by applying the association measure of Bray and Curtis (J. R. Bray and J. T. Curtis, Ecol. Monogr. 27:325-349, 1957) and the UPGMA clustering algorithm (P. H. A. Sneath and R. R. Sokal, Numerical Taxonomy, 1973). No two strains were regarded as being serologically identical unless each gave the same results as the other in each immunodiffusion reaction against every antiserum. Despite the high level of cross-reactions and reactions of identity (totalling 93% of all cell-antiserum combinations) among strains of R. trifolii and R. meliloti, no strains were identical by the criterion described above; however, the strains of these species clustered rapidly and fused at the 70% similarity level. The B. japonicum strains and the rhizobia of the cowpea miscellany were much less cross-reactive (67 and 86% of all combinations were negative, respectively), and they clustered more slowly. The strains of B. japonicum fused completely only at the 4% similarity level, whereas of the 13 cowpea-nodulating strains, 4 reacted as two pairs of identical strains and 6 remained unfused.
通过免疫扩散反应研究了 7 株日本慢生根瘤菌之间的抗原关系，其中每一菌株的细胞都与 7 种相应的抗血清反应。用三叶草根瘤菌（28 株）、苜蓿根瘤菌（9 株）和豇豆根瘤菌属的混合种（13 株）进行了类似的分析。抗原和抗血清只在各自的种内反应；没有进行种间血清交叉反应。定性评分的结果为同反应、交叉反应或无反应，将这些结果形成数据矩阵，并应用 Bray 和 Curtis 的关联度量（J. R. Bray 和 J. T. Curtis，Ecol. Monogr. 27:325-349, 1957）和 UPGMA 聚类算法（P. H. A. Sneath 和 R. R. Sokal，Numerical Taxonomy, 1973）分析菌株之间的关系。除非每株菌在与每种抗血清的每一次免疫扩散反应中都给出与其他株菌相同的结果，否则不认为两株菌在血清学上是相同的。尽管三叶草根瘤菌和苜蓿根瘤菌的菌株之间存在高度的交叉反应和同反应（占所有细胞-抗血清组合的 93%），但根据上述标准，没有任何菌株是相同的；然而，这些种的菌株迅速聚类，并在 70%相似性水平融合。日本慢生根瘤菌菌株和豇豆根瘤菌属的根瘤菌交叉反应性较低（分别为 67%和 86%的组合为阴性），聚类速度较慢。日本慢生根瘤菌的菌株只有在 4%的相似性水平下才能完全融合，而在 13 株豇豆结瘤菌株中，有 4 株反应为两对相同的菌株，有 6 株仍未融合。
