Vigna is a genus of legumes cultivated in specific areas of tropical countries. Species in this genus are important crops worldwide. Vigna species are of great agronomic interest in Venezuela because Vigna beans are an excellent alternative to other legumes. However, this type of crop has some cultivation issues due to sensitivity to acidic soils, high temperatures, and salinity stress, which are common in Venezuela. Vigna species establish symbioses mainly with Bradyrhizobium and Ensifer, and Vigna-rhizobia interactions have been examined in Asia, Africa, and America. However, the identities of the rhizobia associated with V. radiata and V. unguiculata in Venezuela remain unknown. In the present study, we isolated Venezuelan symbiotic rhizobia associated with Vigna species from soils with contrasting agroecosystems or from fields in Venezuela. Several types of soils were used for bacterial isolation and nodules were sampled from environments characterized by abiotic stressors, such as high temperatures, high concentrations of NaCl, and acidic or alkaline pH. Venezuelan Vigna-rhizobia were mainly fast-growing. Sequencing of several housekeeping genes showed that in contrast to other continents, Venezuelan Vigna species were nodulated by rhizobia genus including Burkholderia, containing bacteria from several new phylogenetic lineages within the genus Bradyrhizobium. Some Rhizobium and Bradyrhizobium isolates were tolerant of high salinity and Al toxicity. The stress tolerance of strains was dependent on the type of rhizobia, soil origin, and cultivation history. An isolate classified as R. phaseoli showed the highest plant biomass, nitrogen fixation, and excellent abiotic stress response, suggesting a novel promising inoculant for Vigna cultivation in Venezuela.

中文翻译：

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委内瑞拉不同农业生态条件下与两种绿豆相关的共生细菌的系统发育分析


荠菜是在热带国家的特定地区种植的豆科植物的一个属。该属的物种是全世界重要的农作物。绿豆在委内瑞拉具有重大的农艺价值，因为绿豆是其他豆类的绝佳替代品。然而，由于对酸性土壤、高温和盐分胁迫的敏感性，这类作物存在一些种植问题，这些问题在委内瑞拉很常见。荠菜物种主要与慢生根瘤菌和 Ensifer 建立共生关系，荠菜-根瘤菌的相互作用已在亚洲、非洲和美洲进行了研究。然而，委内瑞拉与 V. radiata 和 V. unguiculata 相关的根瘤菌的身份仍然未知。在本研究中，我们从具有对比农业生态系统的土壤或委内瑞拉的田地中分离出了与 Vigna 物种相关的委内瑞拉共生根瘤菌。使用几种类型的土壤进行细菌分离，并从具有非生物应激源（例如高温、高浓度氯化钠以及酸性或碱性pH）的环境中取样。委内瑞拉的绿豆根瘤菌主要是快速生长的。对几个管家基因的测序表明，与其他大陆不同，委内瑞拉维尼亚物种是由包括伯克霍尔德氏菌在内的根瘤菌属结瘤的，其中含有来自慢生根瘤菌属内几个新系统发育谱系的细菌。一些根瘤菌和慢生根瘤菌分离株能够耐受高盐度和铝毒性。菌株的胁迫耐受性取决于根瘤菌的类型、土壤来源和栽培历史。被归类为 R. Phaseoli 的分离株表现出最高的植物生物量、固氮和出色的非生物胁迫响应，这表明它是一种有前途的委内瑞拉接种剂。