マメ科樹木由来の根粒形成細菌の多様性とその動態

对26株印尼豆科植物根瘤菌的表型、性状、共生特性和遗传变异进行了研究。根据它们的共生模式以及其他表型特征，我们发现这些根瘤菌群内存在着广泛的变异。随机选择的菌株的16S rDNA基因的近全长序列表明，这些菌株可分为三个主要组。第1组与参考菌株热带根瘤菌有较近的亲缘关系，第2组与参考菌株Elkanii有很高的相似性，其余的(第3组)与参考菌株日本慢根瘤菌和脱氮芽孢杆菌关系密切。这一发现也证明了豆科树种金莲花能与速生和慢生根瘤菌以及至少3种根瘤菌建立共生关系并形成根瘤。为了研究结瘤细菌的多样性，采集了冲绳25种植被的根瘤。从结节中分离出21株细菌，进行16S rDNA测序分析。确定了1个新属和一些新种。这表明，从冲绳豆科植物根瘤中分离到的细菌存在着广泛的分化，可能存在局部性和寄主专一性。

Twenty six rhizobial isolates nodulated Indonesian tree legume, Paraserianthes falcataria, were studied for phenotype.characters, symbiotic properties and genetic variation. On the basis of their symbiotic pattern as well as other phenotype characters, we found that there is a wide variation within those rhizobia group. Nearly full-length sequences of 16S rDNA genes of randomly selected isolates showed that the isolates could be divided into three main groups. Group1, which have a closely relationship with reference strains Rhizobium tropicii, group 2 contains isolates which high similarity with reference strain Bradyrhizobium elkanii, and the rest (group 3) were closely related to reference strains Bradyrhizobium japonicum and Blastobacter denitrificans. This present finding also demonstrated that the leguminous tree Paraserianthes falcataria could establish symbiotic relationship and form nodules with both fast growing as well as slow growing rhizobia, and at least with three species of rhizobia.To study for the diversity of the nodule forming bacteria we collected the nodule from 25 kinds of regume in Okinawa. Twenty first bacterial strains were isolates and from the nodules and performed to analysis of 16S rDNA sequencing. One new genus and some new species were determined. It was suggested that the bacteria isolated from nodules of leguminous plants in Okinawa have widely diverged and there is maybe localization and host specificity.