Evaluation of multi-trait plant growth promoting Pseudomonas fluorescens isolated from Constantine Wheat rhizosphere Soil (Algeria) and screening there antifungal activity against two species of Fusarium
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Date
2016-06-12
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Advances in Environmental Biology
Abstract
ABSTRACT
Fluorescent pseudomonas can suppress various soilborne diseases, and their efficacy related both; to their antagonistic activities and
rhizosphere competitiveness. This study was designed to isolate antagonistic Pseudomonas fluorescens from Wheat rhizosphere and
evaluate their Plant promoting traits. Fifty-five antagonistic strainswere isolated from wheat soil, cultivated in Constantine region
(Algeria),characterized morphologically, biochemically and molecularly, and screened for their Plant growth promoting traits. These PGP
traits were analyzed by phosphate solubilization, indol acetic acid (IAA), the production of siderophore, ammonia, hydrogen cyanide
(HCN), and the production of enzyme involved in the suppression of the pathogen like cellulase, pectinase, chitinase, and protease.At the
end, the biocontrol capacity ofthese strainsagainst two speciesof Fusarium: F. culmorum and F. pseudograminearumwas evaluatedin planta.
All the isolates showing a biochemical and morphological of Pseudomonas fluorescens. Under in-vitro conditions,all isolates produced
cellulase and pectinase, 90.9% produced siderophore; hydroxamates type, 96.43% produced IAA.A 96.36% of isolatesproduceda clear
zonearound the colony, exhibiting different sorts of phosphate solubilizing index (PSI) and 76.36% solubilizedthephosphate in liquid
medium, 51.78% produced protease, 48.21% produced lipase, 16.36% produced chitinase, and only 10.9% produced HCN. The selected
strains inhibited Fusariumsp growth when tested in pot experiments. Nine bacterial strains, which showed a maximum plant growth
promoting traits using the molecular identification (16S r DNA gene sequence), were identified as Pseudomonas fluorescens.This study
concludes that strains of Pseudomonas fluorescens, isolated from wheat rhizospheric soil from the region of Constantine (Algeria), showed
variation in their plant promoting characteristics production that can contribute to the ability of these isolates to suppress fungal diseases.
Based on the positive results of the antagonistic effect of selected strains, it is interesting to use the PGPR Pseudomonas fluorescens as
inoculants biofertilizers to replace chemical fertilizers and pesticides for Wheat.