Role of Phosphate and Silicate Solubilizing Bacteria from Saline Soils in Promoting Seed Germination

Abstract

Soil salinity lowers nutrient availability and has a detrimental influence on seed germination and
crop growth. Phosphate-solubilizing bacteria (PSB) and silicate-solubilizing bacteria (SSB) play
an essential role in turning insoluble phosphorus and silicon into bio-available forms, which
improves plant development and stress tolerance. Soil samples were taken from salty and semi-
arid parts of Sangli and Kolhapur districts in Maharashtra, India, to isolate and characterize PSB
and SSB. A total of ten PSB and nine SSB isolates were biochemically analyzed. Under
controlled laboratory conditions, selected isolates were evaluated for their ability to enhance
germination and seedling vigor of Sorghum bicolor. Seeds were infected with individual isolates
and a mixed inoculum, and germination parameters were monitored for up to six days. Microbial
inoculation significantly increased the germination percentage, root and shoot elongation, and
seedling vigor compared to uninoculated controls. PSSB8 consistently outperformed the other
isolates, with the most significant germination percentage (96%), shoot length (9.2 cm), root
length (11.5 cm), and seedling vigour index values. These data suggest that PSSB8 is a suitable
bioinoculant for enhancing seed germination and early crop establishment in saline soils. The
study emphasizes the potential use of PSB and SSB in sustainable agriculture to reduce reliance
on chemical fertilizers while increasing crop output under abiotic stress conditions.