Phosphate-solubilizing peanut associated bacteria: screening for plant growth-promoting activities

Abstract

In the present study, attempts were made to identify the potential of bacterial strains for promoting Arachis hypogaea L. growth. Four hundred and thirty three bacteria were isolated from rhizosphere, phyllosphere and plant tissues from peanuts cultivated in the producing area of Cordoba, Argentina. From this collection, 37 epiphytic isolates and 73 endophytic isolates were selected on the basis of tricalcium phosphate solubilizing activity. These isolates were further tested for other plant growth-promoting attributes and some of them evaluated to examine the effect of inoculation on peanut growth. Siderophore production was observed in a high percentage of the isolates, especially in the root nodule endophytes. Antibiosis was evaluated against the phytopathogen fungus Sclerotinia minor and S. Sclerotiorum. Endophytes from nodules showed the highest levels of fungal growth inhibition. A low number of isolates was able to produce auxin like molecules and inoculation of peanut seedlings with these bacteria showed variability on seed germination enhancement. Isolate J49, identified to belong to genus Pantoea, was the most promising bacterium because it increases peanut plant biomass in inoculation experiments. Peanut soils in the province of Cordoba harbor bacteria with major plant growth promotion properties which represent a potential source of new strains that could be used as biological inoculants in agriculture.

Isolation and selection of plant growth-promoting bacteria associated with sugarcane

“…They are responsible for solubilizing insoluble phosphates into soluble orthophosphate (H 2 PO 4 -or HPO 4 -2 ). For phosphate solubilization, the bacteria must be close to the phosphorus source (Taurian et al 2010). Although rhizobacteria are the most promising as biofertilizers, phosphate solubilizing endophytic bacteria are also described.…”

Advances in plant growth-promoting bacterial inoculant technology: formulations and practical perspectives (1998–2013)

“…This improved performance of PSB for peanuts (Taurian et al 2010). Addition of glycerol to the culture medium preserved the viability of Pseudomonas fluorescens cells in liquid formulation for storage lasting 6 months (Taurian et al 2010).…”

“…This improved performance of PSB for peanuts (Taurian et al 2010). Addition of glycerol to the culture medium preserved the viability of Pseudomonas fluorescens cells in liquid formulation for storage lasting 6 months (Taurian et al 2010). This last finding matches the work of Singleton et al (2002), who developed a liquid formula for Rhizobium by incorporating additives to the media for improved growth performances.…”

Penapisan dan potensi bakteri endofit asal tanaman Arecaceae sebagai agens pengendali hayati cendawan Pestalotiopsis sp. penyebab penyakit bercak daun pada kelapa kopyor (Cocos nucifera) [Selection and potency of endophytic bacteria from Arecaceae as biocontrol agents of Pestalotiopsis sp. causing leaf spot diseae on kopyor coconut (Cocos nucifera)]

“…Tanaman memerlukan bantuan mikroorganisme untuk memproses fosfat sehingga tersedia bagi tanaman. Mikroorganisme tertentu mampu melarutkan fosfat yang tidak tersedia menjadi fosfat tersedia bagi tanaman (Chen et al 2006;Taurian et al, 2010). Bakteri endofit yang mampu melarutkan fosfat, mengeluarkan senyawa organik berberat molekul rendah dengan gugus hidroksil dan karboksil yang mampu mengkelat ion positif pada fosfat kemudian mengkonversinya menjadi bentuk fosfat yang lebih sederhana sehingga dapat digunakan oleh tanaman (Sarker et al, 2014).…”