Isolation of Phosphate Solubilizing Bacteria and their Use for Plant Growth Promotion in Tomato Seedling and Plant

Abstract

Phosphorous (P) is an essential macronutrient and most soils contain high levels of P. However, its availability to plant is limited by rapid immobilization of phosphorous compounds to insoluble forms and hence plant available forms of P in soils are found in low amounts. Phosphate solubilizing bacteria provide an eco-friendly alternative to convert insoluble phosphates into plant available forms. In the present study, three phosphate solubilizing bacterial isolates (PB-1, PB-4 and VC-01) with visually significant phosphate solubilizing abilities were isolated from tomato rhizosphere soil. In-vitro study in pikovskaya’s agar revealed that isolate PB-1 had the highest phosphate solubilizing ability with a phosphate solubilizing index of 2.08±0.07 followed by isolate VC-01 (1.31±0.09) and PB-4 (1.24±0.08). Isolates were used as bacterial inoculum to assess their ability to promote tomato (Lycopersicon esculentum var. Srijana) seedling and plant growth in in-vitro and greenhouse experiment respectively. Isolate PB-4 showed best growth promotion in seedling assay whereas isolate PB-1 and VC-01 also promoted seedling growth compared to control. In greenhouse experiment however, isolates VC-01 and PB-1 significantly enhanced all parameters (shoot length, root length, shoot and root dry weight) compared to uninoculated control whereas isolate PB-4 had a positive effect on all parameters except root length.Kathmandu University Journal of Science, Engineering and TechnologyVol. 13, No. 2, 2017, page: 61-70

Diversity and Phosphate Solubilization Efficiency of Phosphate Solubilizing Bacteria Isolated from Semi-Arid Agroecosystems of Eastern Kenya

“…Pure single colonies were streaked into the middle of the Pikovskaya’s agar plate and then incubated at 28°C for 7 days. The diameter of the bacteria and the cleared zone was measured on the fourth day and used to calculate the Phosphate Solubilization Index (PSI) using the equation below 36 :…”

Immobilization of Heavy Metals in Contaminated Soil using Calcium Phosphate Amendment and Phosphate-solubilizing Fungi (Penicillium sp) in Benin City, Edo state, Nigeria

“…ability to decrease pH creating an acidic environment which enhances the solubility of phosphate in soil. This increment in concentration is attributed to the chelation of heavy metals from their compounds by the action of the hydroxyl and carboxyl groups of the organic acids produced by phosphatesolubilizing organisms, as reported by several studies (Sharma et al, 2011;Pathak et al, 2017). Li et al (2016) agrees that compared to bacteria, PSF have ten times higher in their ability to secrete organic acids.…”

Isolation and Characterization of Plant Growth promoting Rhizobacteria from Bamboo Rhizosphere and Their Role in Plant Growth Promotion

“…Demand-supply gap of bamboo owing to the destruction of natural bamboo resources has become a pressing issue to explore appropriate methods for the mass propagation of bamboo (Ray & Ali 2017). Beneficial effects of PGPR have been reported in many economic-important crops like Brassica juncea (Asghar et al 2002), Vigna radiata (Patten & Glick 2002), Arachis hypogea (Day et al 2004), Triticum aestivum (Ali et al 2008;Hussain & Hasnain 2011;Emami et al 2019), Zea mays (Ruangsanka 2014), Cucumis sativus (Islam et al 2015) Lycopersicon esculentum (Pathak et al 2017;Qessaoui et al 2019) Coffea arabica (Kunwar et al 2018). To date, scanty work has been done regarding the effects of PGPR on the growth and development of bamboo seedlings.…”