Biocontrol properties and functional characterization of rice rhizobacterium pseudomonas sp. VsMKU4036

Abstract

A total of 30 fluorescent pseudomonads (FPs) were showed significant antagonistic activity against different fungal phytopathogens with different level of the zone of inhibition (ZOI) for Rhizoctonia solani (5mm-34mm), Macrophomina phaseolina (9mm-37mm), Scleotium rolfsii (4mm-36mm), Helminthusporium solani (5mm-27mm), Fusarium oxysporum (2mm-25mm) and Fusarium oxysporum RACE (4mm-31mm) compared to control. The maximum growth of our selected isolate VSMKU4036 was observed in King’B Broth (KBB), pH 7.0 and at 37°C. The VSMKU4036 isolate has been recognized as Pseudomonas sp, based on the morphological, biological, and different functional characteristics. Antagonistic rhizobacterium Pseudomonas sp VSMKU4036 produced antimicrobial traits, such as plant growth promotion and various functional characters like siderophores, hydrogen cyanide (HCN), phosphate solubilization, indole acetic acid (IAA), biofilms formation, protease, gelatinase, amylase, and pectinase. Our superior biocontrol isolate VSMKU4036 was high resistance to tetracycline, streptomycin and nalidixic acid, however, it was sensitive to ampicillin and rifamycin. Pseudomonas sp VSMKU4036 showed maximum resistance to cadmium, nickel chloride, copper sulphate, magnesium sulphate, zinc chloride and ferric chloride where as highly sensitive to mercuric chloride, and selenium dioxide compared to control.