Delaware Agricultural Experiment Station, Department of Plant Science, College of Agricultural Sciences, University of Delaware, Newark, Delaware 19717-1303.
Appl Environ Microbiol. 1990 Jan;56(1):224-9. doi: 10.1128/aem.56.1.224-229.1990.
A Collection of 360 isolates of Bradyrhizobium japonicum was developed from soybean (Glycine max [L.] Merrill) nodules taken from 18 locations in Delaware. The isolates were characterized serologically with an enzyme-linked immunosorbent assay, morphologically by colony type on yeast extract-mannitol agar, and for production of rhizobitoxine symptoms with soybean plants. These analyses revealed 12 and 3 groups based on serology and morphology, respectively. The more common identifiable isolates were in serogroups 94, 6, 122, and 76. Nearly 33% of the isolates were rated nonreactive with all of the antisera tested. Overall, 18% of the isolates produced rhizobitoxine symptoms, and these were associated with five known serogroups (31, 46, 76, 94, and 130) and the nonreactive grouping, but with only one colony type. A subsample of 92 isolates was rated for N(2)-fixing ability in the greenhouse and for hydrogenase phenotype in the laboratory. The nitrogen content of plant shoots was strongly and comparably related to both the serological and morphological groupings. Rhizobitoxine and hydrogenase phenotypes were relatively poor predictors of symbiotic effectiveness. Among the serologically reactive isolates, those in serogroups 38-115, 122, and 110 fixed the most N(2), whereas one colony type (that containing isolates producing rhizobitoxine) was clearly inferior to the remaining two morphological groupings. Isolates displaying hydrogenase activity (approximately 15% of the isolates tested) correlated with three serologically reactive groupings (serogroups 110 and 122 and a 122/123 cross-reactive group) and two colony types, none of which coincided with groupings containing bradyrhizobia rated positive for rhizobitoxine production.
从特拉华州 18 个地点采集的大豆（Glycine max [L.] Merrill）根瘤中，开发了 360 株日本慢生根瘤菌（Bradyrhizobium japonicum）分离株。这些分离株通过酶联免疫吸附测定法进行血清学特征分析，通过酵母提取物甘露醇琼脂上的菌落类型进行形态学分析，并用大豆植株产生根瘤菌毒素症状进行分析。这些分析分别基于血清学和形态学确定了 12 个和 3 个组。更常见的可识别分离株分别属于血清组 94、6、122 和 76。几乎 33%的分离株与所有测试的抗血清均无反应。总体而言，18%的分离株产生根瘤菌毒素症状，这些症状与 5 个已知血清组（31、46、76、94 和 130）和无反应组有关，但仅与一种菌落类型有关。92 个分离株的子样本在温室中被评定为固氮能力，并在实验室中评定产氢酶表型。植株地上部分的氮含量与血清学和形态学分组都有强烈的可比性。根瘤菌毒素和产氢酶表型是共生有效性的相对较差的预测因子。在血清学反应的分离株中，血清组 38-115、122 和 110 中的分离株固定氮的能力最强，而一种菌落类型（包含产生根瘤菌毒素的分离株）明显逊于其余两种形态分组。表现出氢酶活性的分离株（约占测试分离株的 15%）与三个血清学反应性分组（血清组 110 和 122 以及 122/123 交叉反应性分组）和两种菌落类型相关，其中没有一种与被认为产生根瘤菌毒素的分离株的分组相吻合。
