A total of 87 FPs have been isolated from tomato (Lycopersicon esculentum) rhizosphere and evaluated by dual plate assay method for the antimicrobial activity of Ralstonia solanacearum. Of which, 30 FPs showed antagonistic activity against R. solanacearum with the zone of inhibitions (ZOI) ranging from 19 mm to 28 mm. Similarly, antagonistic FPs significantly controlled various fungal phytopathogens such as Rhizoctonia solani (6.3 mm−20 mm), Macrophomina phaseolina (8.7 mm−19.3 mm), Fusarium oxysporum (7.3 mm−30.7 mm), and Sclerotium rolfsii (5.3 mm−21 mm). The cell-free culture filtrate of Pseudomonas sp VSMKU3054 significantly suppressed the fungal pathogens and increased the root and shoot length of the tomato seedlings compared to the control. Furthermore, the antagonistic FPs effectively produced lytic enzymes and antimicrobial traits such as amylase (6), protease (30), cellulase (28), pectinase (12), chitinase (22), gelatinase (27), siderophore (28), hydrogen cyanide (25), phosphate solubilization (30), and Indole acetic acid (IAA) (23). Genetic diversity of FPs was assessed by BOX-PCR with specific primers revealed that two distinct clusters were observed, whereas, RFLP analyses were showed that 5 to 16 bands ranged from 75 bp to 1.2 bp with two major clusters using restriction enzyme HaeIII. The antibiotic encoding genes were detected from FPs, of which 10 FPs were positive for 2,4-diacetylphloroglucinol (DAPG), 9 FPs were positive for pyoleuterin (PLT), 10 FPs were positive for hydrogen cyanide (HCN) and none of them obtained pyrrolnitrin (PRN) with respective primers. Based on the superior antagonistic isolates against R. solanacearum and phytofungal pathogens and other antimicrobial traits, the isolate VSMKU3054 was selected for further studies. Based on the morphological, physiological and 98% of 16 s rDNA sequence similarity, the selected isolate VSMKU3054 was identified as Pseudomonas fluorescens. Further, the potential isolate P. fluorescens VSMKU3054 and cell free culture filtrate remarkably enhance tomato seedling growth such as root and shoot length, fresh and dry weight and vigor index compared to control. This study indicated that rhizospheric isolates of FPs have more potential for plant growth promotion and plant protection from plant pathogenic microbes.

从番茄（Lycopersicon esculentum）根际分离到87种FPs，并用双平板法评估了青枯菌的抑菌活性。其中30个FP表现出对青枯菌的拮抗活性，其抑菌圈（ZOI）范围在19毫米至28毫米之间。类似地，拮抗FPs可以显着控制各种真菌性植物病原体，例如茄红枯萎病菌（6.3 mm-20 mm），菜豆大红霉菌（8.7 mm-19.3 mm），尖孢镰刀菌（7.3 mm-30.7 mm）和罗氏菌菌（5.3 mm-21mm） ）。假单胞菌的无细胞培养滤液与对照相比，sp VSMKU3054显着抑制了真菌病原体，并增加了番茄幼苗的根和茎长。此外，拮抗FPs有效产生裂解酶和抗菌特性，例如淀粉酶（6），蛋白酶（30），纤维素酶（28），果胶酶（12），几丁质酶（22），明胶酶（27），铁载体（28），氢氰化物（25），磷酸盐溶解（30）和吲哚乙酸（IAA）（23）。通过BOX-PCR特异性引物评估FPs的遗传多样性，发现观察到两个不同的簇，而RFLP分析显示，使用限制性内切酶Hae在5个至16个条带范围从75 bp到1.2 bp不等，其中两个主要簇三，从FPs中检测到抗生素编码基因，其中10个FPs对2,4-二乙酰基间苯三酚（DAPG）呈阳性，9个FPs对肾上腺素（PLT）呈阳性，10个FPs对氰化氢（HCN）呈阳性，但均未获得吡咯硝菌素（PRN）和相应的引物。基于针对青枯菌和植物真菌病原体及其他抗菌特性的优良拮抗菌株，选择了分离株VSMKU3054进行进一步研究。根据形态，生理学和16 s rDNA序列的98％相似性，选定的分离株VSMKU3054被鉴定为荧光假单胞菌。此外，潜在分离物荧光假单胞菌与对照相比，VSMKU3054和无细胞培养滤液显着增强了番茄幼苗的生长，例如根和茎长，鲜重和干重以及活力指数。这项研究表明，FPs的根际分离株具有更多的促进植物生长和植物免受植物病原微生物侵害的潜力。