Symbiotic biological nitrogen fixation (BNF) is a complex process that involves rhizobia, a diverse group of α and β-proteobacteria bacteria, and legume species. Benefits provided by BNF associated with legume trees in tropical environments include improvements to efficiency of nitrogen (N) use, increase of soil carbon sequestration, stabilization of soil organic matter, decrease of soil penetration resistance, and improvement of soil fertility. All these benefits make BNF a crucial ecosystem service to the sustainability of tropical agriculture. Due to the importance of this ecological process and the high diversity of rhizobia, these bacteria have been extensively characterized worldwide. Currently, over 400 species of rhizobia are known, distributed into seven families. In the humid tropics, Leucaena leucocephala, Acacia mangium, Gliricidia sepium, and Clitoria fairchildiana are four of the most common species used by family farmers to create sustainable agricultural systems. These four legumes perform symbiosis with different groups of rhizobia. Exploring BNF could help to enable sustainable intensification of agriculture in the humid tropics, mainly because it can increase N use efficiency in an environment where N is a limiting factor to plant growth.

中文翻译：

---

根瘤菌的多样性及其与豆科植物的相互作用对热带农业系统的可行性和可持续性的重要性

共生生物固氮（BNF）是一个复杂的过程，涉及根瘤菌，各种α和β变形杆菌细菌以及豆类物种。BNF在热带环境中与豆类树相关的好处包括提高氮素利用效率，增加土壤固碳能力，稳定土壤有机质，降低土壤渗透阻力以及提高土壤肥力。所有这些好处使BNF成为热带农业可持续发展的关键生态系统服务。由于这种生态学过程的重要性以及根瘤菌的高度多样性，这些细菌已在全球范围内得到广泛表征。目前，已知有400多种根瘤菌，分布在七个科中。在潮湿的热带地区银合欢，马占相思，南洋樱， 和Clitoria fairchildiana是使用农民家庭，以建立可持续的农业系统中最常见的物种中的四个。这四种豆科植物与不同种类的根瘤菌共生。探索BNF有助于在潮湿的热带地区实现农业可持续集约化，主要是因为它可以在N限制植物生长的环境中提高N的利用效率。