Abstract

In the framework of the comprehensive research of Far Eastern natural populations of soybean nodule bacteria, laboratory experiments have been conducted at the All-Russia Scientific Research Institute of Soybean (Blagoveshchensk) with the purpose to identify distinctive features of rhizobia species Sinorhizobium fredii (Scholla and Elkan, 1984) and Bradyrhizobium japonicum (Jordan, 1982) whose pure cultures were isolated from soils of Far Eastern regions practicing soybean cultivation. It is established that B. japonicum strains start growing in Petri dishes on the seventh to tenth and even on the 20th day after the inoculation, assimilate a limited number of carbon nutrition sources, release mostly alkaline metabolic products, and feature a relatively low osmotic resistance. Representatives of this species are susceptible to extreme environmental conditions; their growth sharply slows down on acidic and alkaline nutrient media and stops at high (37–42°C) temperatures. However, under the optimal conditions, this rhizobia species dominates in the nodulation of soybean plants due to its high and persistent virulence. The restriction analysis of the studied B. japonicum strains confirmed their identity. S. fredii strains start growing in Petri dishes on the second to fourth day after the inoculation, assimilate well a broad spectrum of carbon nutrition sources, and release acidic metabolic products. Most strains of this species feature high osmotic resistance. Cultures retaining universal growth capacity under extreme environmental conditions (high temperatures and low and high pH values) have been identified in the group of S. fredii strains. This rhizobia species can predominate in the formation of symbiotic mechanisms in years featuring extreme weather conditions. Enzymatic fermentation of gene 16S rRNA in the studied S. fredii strains was performed using restriction enzyme HaeIII; the analysis of the fermentation results confirmed the identity of these strains. The RAPD-PCR analysis has demonstrated the intraspecific specificity of the studied B. japonicum and S. fredii strains: these species feature high degrees of polymorphism reflecting their population heterogeneity.

中文翻译：

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栖于俄罗斯远东土壤上的根瘤菌种Sfrindhizobium fredii和Bradyrhizobium japonicum的独特特征

摘要

在远东大豆根瘤菌自然种群的综合研究框架内，已在全俄罗斯大豆科学研究所（布拉戈维申斯克）进行了实验室实验，目的是鉴定根瘤菌种Sinorhizobium fredii（Scholla and Elkan（1984）和Bradyrhizobium japonicum（Jordan，1982）的纯培养物是从远东地区进行大豆种植的土壤中分离出来的。确定日本血吸虫菌株在接种后的第七至第十天甚至第二十天开始在陪替氏培养皿中生长，吸收有限数量的碳营养源，释放大部分碱性代谢产物，并且具有较低的渗透阻力。该物种的代表易受极端环境条件的影响。它们在酸性和碱性营养培养基上的生长会急剧减慢，并在高温（37–42°C）下停止。然而，在最佳条件下，这种根瘤菌由于其高而持久的毒力而在大豆植株的根瘤形成中占主导地位。对所研究的日本血吸虫菌株的限制性酶切分析证实了它们的身份。弗雷德氏菌接种后第二到第四天，菌株在培养皿中开始生长，可以很好地吸收各种碳营养源，并释放出酸性代谢产物。该种类的大多数菌株具有高的抗渗透性。在S. fredii菌株组中已鉴定出在极端环境条件（高温，低pH和高pH值）下具有通用生长能力的培养物。在具有极端天气条件的年份中，这种根瘤菌物种可能在共生机制的形成中占主导地位。使用限制酶Hae对16. rRNA基因在所研究的S. fredii菌株中进行酶促发酵III; 发酵结果的分析证实了这些菌株的身份。的RAPD-PCR分析证明所研究的种内特异性B.血吸虫和S.根瘤菌菌株：这些物种具有高度多态性反映了他们在人口异质性。