Combined Antimicrobial Activity of Chromolaena odorata, Azadirachta indica Leaf Extract, against Streptomyces scabiei (Plant pathogen) and Paenibacillus polymyxa, and their interaction
FTIR analysis; GC-MS analysis; MBC; MIC; Phytochemical analysis; Well diffusion
Streptomyces scabiei is a gram-positive soil dwelling actinobacteria, that causes the scab disease in many plants, especially in potatoes. This causes black blotches on the tuber that negatively impacts the economic and market worth of potatoes. Plant species like Chromolaena odorata and neem are known for their antibacterial potential against common human microflora and agricultural pathogens. Aiming to find natural solutions to plant pathogens, the current study analyzes, the antimicrobial effect of these plant extracts at different concentrations using well diffusion, MIC and MBC. Combination study was also performed to test the synergistic antimicrobial effect against Streptomyces scabiei. In addition, another soil dwelling bacteria, Paenibacillus polymyxa, known for its plant growth promoting potential was also tested against the plant pathogen to understand microbe-microbe interactions through cross streak assay. Both plant extracts showed promising antimicrobial effect against Streptomyces scabiei, however, they showed very less antimicrobial potential against the plant growth promoting bacterium. Moreover, cross streak assay showed that both the bacterium coexisted together. Hence, further studies can be conducted to formulate a biofertilizer containing the two-plant extract in optimum concentrations and Paenibacillus polymyxa to prevent scab disease and also enhance plant growth. 2025, Crop Protection Research Centre. All rights reserved.
Journal of Biopesticides;Volume;18;Issue;2;pp.167-176
https://doi.org/10.57182/jbiopestic.18.2.167-176 https://www.scopus.com/pages/publications/105031653087?origin=resultslist
Lijo H.L., Christ University, Bangalore Central Campus, Hosur Road, Near Dairy Circle, Karnataka, Bangalore, 560029, India; Sandheep P.N., Christ University, Bangalore Central Campus, Hosur Road, Near Dairy Circle, Karnataka, Bangalore, 560029, India