Abstract

The global jasmine flower market has grown significantly over the decades, often relying heavily on synthetic agrochemicals to meet the increasing demand. However, growing concerns about the environmental impact of chemical-based floriculture have shifted attention towards green alternatives. Microbial plant growth promoters (PGP) offer promising bio-based and safe solutions. The present study focused on six PGP isolates belonging to the genus Pseudomonas, isolated from the rhizosphere soils of the geographical indication tagged Udupi Jasmine cultivated in Karnataka, India. This study involved isolation and functional characterization, followed by evaluation using bioassays and pot culture experiments. The isolates exhibited multiple beneficial traits. The green gram seeds treated with strains NPS-18 and NPS-6 exhibited 100% germination compared to only 6.66 ± 0.28% in the untreated control after 17 h. All isolates produced key phytohormones, including indole acetic acid and gibberellic acid, improving plant growth indices. The pot culture experiment showed that isolate NPS-18 was the most promising strain in terms of growth enhancement. This strain was identified as Pseudomonas aeruginosa using 16S rRNA gene sequencing. Overall, the versatile functional properties of the native PGP strains demonstrate their potential for use in sustainable jasmine cultivation.

Key words: Floriculture, Bioinoculant, Phytohormones, Siderophores, Seed germination, Eco-friendly