Saikia , R and Sarma, R K and Yadav, A and Bora, T C (2011) Genetic and functional diversity among the antagonistic potential fluorescent Pseudomonada isolated from tea rhizosphere. Current Microbiology, 62 (2). pp. 434-444.

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Twenty-five fluorescent pseudomonads from rhizospheric soil of six tea gardens in four district of Upper Assam, India were isolated and screened for antagonistic activity against fungal pathogens such as Fusarium oxysporum f. sp. raphani (For), Fusarium oxysporum f. sp. ciceri (Foc), Fusarium semitectum (Fs), and Rhizoctonia solani (Rs); and bacterial pathogens 14Staphylococcus aureus (Sa), Escherichia coli (Ec), and Klebsiella pneumoniae (Kp). Most of the isolates exhibited strong antagonistic activity against the fungal pathogens and gram-positive bacterium i.e. Staphylococcus aureus. Productions of siderophore, salicylic acid (SA), hydrogen cyanide (HCN), and cell wall-degrading enzyme (chitinase) were studied to observe the possible mechanisms of antagonistic activity of the isolates. Correlation between the antagonistic potentiality of some isolates and their levels of production of siderophore, salicylic acid, and hydrogen cyanide was observed. Out of the 25 isolates, antibiotic-coding genes, 2,4-diacetylphloroglucinol (DAPG) and pyoluteorin (PLT) were detected in the isolates, Pf12 and Pf373, respectively. Genetic diversity of these fluorescent pseudomonads were analyzed with reference to four strains of Pseudomonas fluorescens NICM 2099T, P. aeruginosa MTCC 2582T, P. aureofaciens NICM 2026T, and P. syringae MTCC 673T. 16S rDNA-RFLP analysis of these isolates using three tetra cutter restriction enzymes (HaeIII, AluI and MspI) revealed two distinct clusters. Cluster A comprised only two isolates Pf141 and 24-PfM3, and cluster B comprised 23 isolates along with four reference strains.

Item Type: Article
Uncontrolled Keywords: Genetic and Functional Diversity, Antagonistic Potential Fluorescent Pseudomonads, Tea Rhizosphere
Subjects: Biology > Biotechnology
Depositing User: Dr. PK Barooah
Date Deposited: 22 Oct 2011 06:07
Last Modified: 22 Oct 2011 06:07

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