Abstract

The objective of this study was to evaluate the relationship of nutrients in Ora-pro-nobis to the physical-chemical attributes and the communities of N₂-fixing bacteria and arbuscular mycorrhizal fungi of the soils in the southern part of the state of Minas Gerais, Brazil. Rhizospheric soil, root, and leaf samples were collected from 12 sampling points in four neighboring municipalities. N₂-fixing bacteria from rhizospheric soil, roots, and washed roots macerated in water were isolated using a N-free semi-solid medium, and the 16S rRNA gene was sequenced. Arbuscular mycorrhizal fungi spores were extracted from the soil by the wet-sieving method, followed by sucrose-gradient centrifugation. The collected roots were cleared and analyzed according to the traditional methods for the evaluation of mycorrhizal colonization. The soil samples and leaves were analyzed for physical-chemical and chemical attributes, respectively. There was no relationship between the total nitrogen in the soil and the protein content (based on N content) in the leaf of Ora-pro-nobis as well as between the concentration of the other nutrients in the leaf and their corresponding concentration in the soil, except for potassium and magnesium. Of the 86 isolates obtained, 70 were identified in the genus of the N₂-fixing bacteria Azospirillum. There was a variation in spore density and mycorrhizal colonization. The families Ambisporaceae, Archaeosporaceae, Claroideogloraceae, Glomeraceae, Acaulosporaceae, Diversisporaceae, and Gigasporaceae were identified. Associative N₂-fixing bacteria and arbuscular mycorrhizal fungi were abundantly found in close relationship with Ora-pro-nobis, which may explain the ability of this plant to sustain high protein content in its leaves even in soils with relatively low nitrogen concentration.

中文翻译：

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营养原与土壤化学和物理特性以及促进植物生长的微生物相关，而原先的Ora-pro-nobis（Pereskia aculeata Mill。）营养

摘要

这项研究的目的是评价营养物质ORA-亲诺比斯物理化学属性和N的社区关系₂ -定影细菌和土壤的丛枝菌根真菌在米纳斯吉拉斯州的南部地区， 巴西。从四个邻近城市的12个采样点采集了根际土壤，根和叶样品。N ₂使用无氮的半固体培养基分离根际土壤中固定的细菌，根和浸在水中的根，然后使用16N rRNA基因进行测序。通过湿筛法从土壤中提取丛枝菌根真菌孢子，然后进行蔗糖梯度离心。根据传统方法对菌根定殖进行评估，清理并分析收集的根。对土壤样品和叶片分别进行了理化和化学分析。土壤中的总氮与Ora-no-nobis叶片中的蛋白质含量（基于N含量）之间以及叶片中其他养分的浓度与其在土壤中的相应浓度之间没有关系，钾和镁除外。₂固定细菌固氮螺菌。孢子密度和菌根定植存在差异。确定了双足纲科，古纲科，腕足纲科，glomeraceae，棘皮纲科，Diverssisporaceae和Gigasporaceae科。大量发现了与N ₂固定的缔合细菌和丛枝菌根真菌与Ora-pro-nobis密切相关，这也许可以解释这种植物即使在氮含量相对较低的土壤中也能维持其叶片中高蛋白质含量的能力。