Isolation and molecular characterization of endophytic bacteria from peppermint, chamomile, asparagus and antagonistic effect of isolates on fungal plant pathogens

The endophytic bacteria are non-pathogenic organisms residing plant tissues which produced growth factors to increase metabolism, growth and resistance of plants to the pathogens and environmental tensions. The present study was aimed (i) to isolate and molecular characterization of endophytic bacteria from peppermint, chamomile, and asparagus (ii) to investigate antagonistic effect of isolates on fungal pathogens including Aspergillus niger, Alternaria alternata, Fusarium oxysporum and Mucor hiemalis (iii) to survey of isolates effect on plant growth characters.
The endophytic bacteria were isolated from root tissue of peppermint, chamomile, and asparagus. The antagonistic effect of endophytic isolates were investigated on fungal pathogens including Alternaria alternata, Fusarium oxysporum and Mucor hiemalis using agar well diffusion assay testing on Mueller-Hinton agar. The seeds of plants inoculated to the bacterial suspension and then were cultured in vases containing 300 g soil. The isolates effect was studied on plant growth parameters and analyzed by statistical software SAS 9.2.
A total of 6 endophytic bacteria (E1-E6) belonging Bacillus sp. were isolated from the plant root. The statistical and variance analysis indicated significance effect of isolates on fungal pathogens inhibition and plant growth improvement. The growth of peppermint, chamomile, and asparagus were showed high length of the plants which had been treated with the endophytic bacteria rather than the non-treatment of plants.
Discussion and In this study, the endophytic bacteria were isolated from peppermint, chamomile, and asparagus, then verified antagonistic effect of isolates on current fungal pathogens, also on plant growth improvement. Regarding the potential of endophytic bacteria, the organisms can be used as biocontrols in agriculture, increasing resistance of plants against fungal pathogens, environmental stresses and improving growth of plants.