Botany and Microbiology Department, Faculty of Science, Assiut University, Assiut, 71516, Egypt.
Botany and Microbiology Department, Faculty of Science, New Valley University, El-Kharga, 72511, Egypt.
BMC Microbiol. 2024 Nov 6;24(1):454. doi: 10.1186/s12866-024-03591-z.
This study investigates non-rhizobial endophytic bacteria in the root nodules of chickpea (Cicer arietinum L), faba bean (Vicia faba), and cowpea (Vigna unguiculata L. Walp), as well as arbuscular mycorrhizal fungi in the rhizospheric soil of chickpea and faba bean. Out of the 34 endophytic bacterial populations examined, 31 strains were identified as non-rhizobial based on nodulation tests. All strains were assessed for their plant growth-promoting (PGP) activities in vitro. The results revealed that most isolates exhibited multiple PGP activities, such as nitrogen fixation, indole-3-acetic acid (IAA) and ammonia (NH) production, phosphate solubilization, and exopolysaccharide production. The most effective PGP bacteria were selected for 16S rRNA analysis. Additionally, a total of 36 species of native arbuscular mycorrhizal fungi (AMF) were identified. Acaulospora (100%) and Scutellospora (91.66%) were the most prevalent genera in Cicer arietinum L. and Vicia faba L. plants, respectively. Acaulospora also exhibited the highest spore density and relative abundance in both plants. Moreover, the root colonization of Cicer arietinum L. and Vicia faba L. plants by hyphae, vesicles, and arbuscules (HVA) was significant. The findings of this study provide valuable insights into non-rhizobial endophytic bacteria associated with legume root nodules and the diversity of AMF. These organisms have great potential for PGP and can be manipulated by co-inoculation with rhizobia to enhance their biofertilizer effectiveness. This manipulation is crucial for promoting sustainable agriculture, improving crop growth, and advancing biofertilizer technology.
本研究调查了鹰嘴豆（Cicer arietinum L）、蚕豆（Vicia faba）和豇豆（Vigna unguiculata L. Walp）根瘤中的非根瘤内生细菌，以及鹰嘴豆和蚕豆根际土壤中的丛枝菌根真菌。在检查的 34 个内生细菌种群中，有 31 株根据结瘤试验被鉴定为非根瘤菌。所有菌株均在体外评估其植物促生（PGP）活性。结果表明，大多数分离株表现出多种 PGP 活性，如固氮、吲哚-3-乙酸（IAA）和氨（NH）产生、磷酸盐溶解和胞外多糖产生。选择最有效的 PGP 细菌进行 16S rRNA 分析。此外，共鉴定出 36 种本地丛枝菌根真菌（AMF）。无梗囊霉（Acaulospora）（100%）和盾巨孢囊霉（Scutellospora）（91.66%）分别是鹰嘴豆和蚕豆植物中最普遍的属。无梗囊霉在这两种植物中的孢子密度和相对丰度均最高。此外，鹰嘴豆和蚕豆植物的根系被菌丝、泡囊和丛枝（HVA）定殖的程度显著。本研究的结果为与豆科植物根瘤相关的非根瘤内生细菌和 AMF 的多样性提供了有价值的见解。这些生物体具有巨大的 PGP 潜力，可以通过与根瘤菌共接种来操纵，以提高其生物肥料的有效性。这种操纵对于促进可持续农业、改善作物生长和推进生物肥料技术至关重要。
