Metabolic Profiling of Plant Growth Promoting Microorganisms (PGPMs) from Chickpea Rhizosphere and Their Antagonistic Activity against Dry Root Rot Pathogen Rhizoctonia bataticola

Dry root rot (DRR) caused by Rhizoctonia bataticola is the major threat to chickpea production globally. Recently, upsurge in disease incidence is observed due to unexpected increase in temperature and soil moisture stress resultant of changing climatic scenarios. To combat this necrotrophic phytopathogenic fungus, the present study was conducted with the aim of managing the disease by using potential rhizospheric PGPMs.

Twenty-six isolates of soil-borne fungal PGPMs were isolated from rhizosphere of chickpea in North Eastern Karnataka zone and screened for bio-active compounds production against Rhizoctonia bataticola by inverted plate technique. Using ITS genes BLAST analysis, the putative rhizospheric fungal PGPM was identified at the molecular level. Finally, chemical characterization of the bio-active compounds and metabolic profiling was carried out using Gas Chromatography Mass Spectrometry (GC-MS) technique.

All the isolates showed significant differences in radial growth of mycelium at five days after incubation. SFPGPM-13 isolate produced maximum concentration of bio-active compounds with per cent mycelial inhibition of 62.83 (52.43). Molecular identification and BLAST analysis showed the isolate SFPGPM-13 was identified as Trichoderma harzianum. GC-MS analysis resulted that 62 compounds were present in the extract of SFPGPM-13 at different retention time and mass to charge (m/z) ratio.