Plant growth-promoting bacteria (PGPB) can be used as a safe and sustainable agricultural measure to increase plant yield. In this study, cultivable rhizospheric, endophytic, and epiphytic bacteria associated with canola were isolated on nutrient agar medium. The SDS-PAGE method was used for grouping the bacterial strains. Bacterial strains with more than 80% similarity in their protein patterns were placed in the same species and selected as a representative for partial 16S rRNA encoding gene sequence analysis. It was found that the bacteria used in this study belonged to Pseudomonas, Frigoribacterium, Sphingomonas, Sphingobacterium, Microbacterium, Bacillus, and Rhodococcus genera. Three PGP bioactivities including siderophore production, nitrogen fixation ability, and phosphate solubilization were evaluated for 18 Pseudomonas representative strains. All tested strains were able to produce siderophore, although only 5 strains could fix nitrogen and none was able to solubilize phosphate. Greenhouse experiments showed that 4 bacterial strains (i.e., 8312, 642, 1313W, and 9421) significantly affected canola seed germination and seedling growth. Bacterial strain 8312, which was identified as Pseudomonas sp., showed the highest effect on the growth of the canola plant. These results indicated the potential of strain 8312 to be used as a biofertilizer in canola cultivation. The results of this research indicated that canola-related bacteria were diverse during the flowering stage. One isolate had a significant effect on all canola plant growth factors in the greenhouse. Hence, it is recommended to investigate this strain further in field infestation experiments.

中文翻译：

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伊朗西部油菜植物优势菌的遗传多样性和植物促生长活性

植物生长促进菌 (PGPB) 可作为一种安全且可持续的农业措施来提高植物产量。在这项研究中，在营养琼脂培养基上分离了与油菜相关的可培养的根际、内生和附生细菌。使用 SDS-PAGE 方法对细菌菌株进行分组。将蛋白质模式相似度超过80%的细菌菌株置于同一物种中，并选择作为部分16S rRNA编码基因序列分析的代表。发现本研究中使用的细菌属于假单胞菌属、冷菌属、鞘氨醇单胞菌属、鞘氨醇杆菌属、微杆菌属、芽孢杆菌属和红球菌属。三种 PGP 生物活性，包括铁载体产生、固氮能力、评估了 18 种假单胞菌代表性菌株的磷酸盐溶解性​​。所有测试的菌株都能够产生铁载体，尽管只有 5 个菌株可以固氮，没有一个能够溶解磷酸盐。温室试验表明，4 种菌株（即 8312、642、1313W 和 9421）显着影响油菜种子的萌发和幼苗生长。被鉴定为假单胞菌属的细菌菌株 8312 对油菜植物的生长表现出最高的影响。这些结果表明菌株 8312 在双低油菜籽栽培中用作生物肥料的潜力。这项研究的结果表明，油菜花相关细菌在开花期是多种多样的。一种分离物对温室中的所有油菜植物生长因子具有显着影响。因此，