Journal of Pure and Applied MicrobiologyVol. 9 No. 1

Metabolites in Control of Rhizoctonia bataticola

Poonam Kumari1, Veena Khanna2, Palika Sharma1 and Suman Kumari1

1Department of Microbiology, 2Department of Plant Breeding and Genetics Punjab Agricultural University, Ludhiana 141004, Punjab, India.

Received on 10 September 2014 and accepted on 11 November 2014

 

ABSTRACT

Agrochemicals used for crop production adversely affect both human and environmental health. The search for bacterial antagonists is a step towards agricultural sustainability. The inhibition of?Rhizoctonia bataticola, causing dry root rot of chickpea was exhibited by 59 out of 174 rhizobacterial strains. Out of which, 35 strong inhibitors (16 belonging to Pseudomonas sp. and 19 representatives of Bacillus sp.) were characterized for inhibitory traits. Production of diffusible metabolites by 16 isolates (7 of Pseudomonas sp. and 9 of Bacillus sp.) reduced the radial proliferation of pathogen suggesting the role of antibiosis in antagonism. Culture filtrate of 28 antagonists @ 50% inhibited growth of test fungus in the range of 11.1-71.25%. Fungal growth inhibition in response to thermo-stable metabolites was observed with 22 rhizobacterial isolates in the range of 11.7-36.6 %. Extracts of antimetabolites in ethyl acetate inhibited the growth of fungus in the range of 28.7-42.5%. Role of volatile antimetabolites in antagonism was evaluated and found positive with 23 antagonistic isolates while all were amylase producers. SEM revealed scanty growth with distorted cell surface morphology of test fungus in response to antagonistic effect.

Keywords : Diffusible metabolites, Antibiosis, Amylase.