Centre de Biotechnologies Végétale Et Microbienne, Biodiversité Et Environnement, Faculté Des Sciences, Université Mohammed V de Rabat, 4, Avenue Ibn Battouta, Agdal, BP 1014 RP, Rabat, Morocco.
Centre de Recherche Forestière, Département Des Eaux Et Forêts, Avenue Omar Ibn El KhattabAgdal, BP 763, 10050, Rabat, Morocco.
Microb Ecol. 2022 Oct;84(3):794-807. doi: 10.1007/s00248-021-01888-4. Epub 2021 Oct 9.
In this work, we analyzed the symbiotic performance and diversity of rhizobial strains isolated from the endemic shrubby legume Chamaecytisus albidus grown in soils of three different agroforestry ecosystems representing arid and semi-arid forest areas in Morocco. The analysis of the rrs gene sequences from twenty-four representative strains selected after REP-PCR fingerprinting showed that all the strains belong to the genus Bradyrhizobium. Following multi-locus sequence analysis (MLSA) using the rrs, gyrB, recA, glnII, and rpoB housekeeping genes, five representative strains, CA20, CA61, CJ2, CB10, and CB61 were selected for further molecular studies. Phylogenetic analysis of the concatenated glnII, gyrB, recA, and rpoB genes showed that the strain CJ2 isolated from Sahel Doukkala soil is close to Bradyrhizobium canariense BTA-1 (96.95%); that strains CA20 and CA61 isolated from the Amhach site are more related to Bradyrhizobium valentinum LmjM3, with 96.40 and 94.57% similarity values; and that the strains CB10 and CB60 isolated from soil in the Bounaga site are more related to Bradyrhizobium murdochi CNPSo 4020 and Bradyrhizobium. retamae Ro19, with which they showed 95.45 and 97.34% similarity values, respectively. The phylogenetic analysis of the symbiotic genes showed that the strains belong to symbiovars lupini, genistearum, and retamae. All the five strains are able to nodulate Lupinus luteus, Retama monosperma, and Cytisus monspessilanus, but they do not nodulate Glycine max and Phaseolus vulgaris. The inoculation tests showed that the strains isolated from the 3 regions improve significantly the plant yield as compared to uninoculated plants. However, the strains of Bradyrhizobium sp. sv. retamae isolated from the site of Amhach were the most performing. The phenotypic analysis showed that the strains are able to use a wide range of carbohydrates and amino acids as sole carbon and nitrogen source. The strains isolated from the arid areas of Bounaga and Amhach were more tolerant to salinity and drought stress than strains isolated in the semi-arid area of Sahel Doukkala.
在这项工作中，我们分析了从摩洛哥干旱和半干旱森林地区三种不同农林生态系统中生长的特有灌木豆科植物 Chamaecytisus albidus 中分离出的根瘤菌菌株的共生性能和多样性。对 24 株经 REP-PCR 指纹图谱分析后选定的代表性菌株的 rrs 基因序列分析表明，所有菌株均属于慢生根瘤菌属。通过使用 rrs、gyrB、recA、glnII 和 rpoB 看家基因的多位点序列分析 (MLSA)，选择了 5 株代表性菌株 CA20、CA61、CJ2、CB10 和 CB61 进行进一步的分子研究。glnII、gyrB、recA 和 rpoB 基因的系统发育分析表明，从 Sahel Doukkala 土壤中分离出的菌株 CJ2 与 Canariense BTA-1 （96.95%）密切相关；从 Amhach 地点分离出的菌株 CA20 和 CA61 与 Valentinum LmjM3 具有更高的相似性，相似度值分别为 96.40%和 94.57%；而从 Bounaga 地点土壤中分离出的菌株 CB10 和 CB60 与 Bradyrhizobium murdochi CNPSo 4020 和 Bradyrhizobium retamae 具有更高的相似性，相似度值分别为 95.45%和 97.34%。共生基因的系统发育分析表明，这些菌株属于共生体 lupini、genistearum 和 retamae。所有 5 株菌都能结瘤 Lupinus luteus、Retama monosperma 和 Cytisus monspessilanus，但不能结瘤 Glycine max 和 Phaseolus vulgaris。接种试验表明，与未接种植物相比，从 3 个地区分离出的菌株显著提高了植物的产量。然而，从 Amhach 地区分离出的 Bradyrhizobium sp. sv. retamae 菌株表现最为出色。表型分析表明，这些菌株能够利用广泛的碳水化合物和氨基酸作为唯一的碳氮源。从 Bounaga 和 Amhach 干旱地区分离出的菌株比从 Sahel Doukkala 半干旱地区分离出的菌株对盐度和干旱胁迫更具耐受性。
