Vol. 11, Issue 7 (2022)

Author(s):
Kuldeep Singh, Rajesh Gera, Jagdish Parshad, Dinesh Kumar and Sushil Kumar Singh

Abstract:
A total of 50 Sesbania rhizobial isolates growing in different zones of India were used to investigate their intrinsic resistance to different concentrations of eight antibiotics viz., ampicillin, chloramphenicol, Gentamycin, Kanamycin, nalidixic acid, Tetracyclin streptomycin and neomycin. Most of the isolates were found to be resistant to five antibiotics viz., ampicillin, chloramphenicol, gentamycin, nalidixic acid and streptomycin up to a concentration of 100 µg ml^-1 after 4 days of incubation. However, most of the isolates were sensitive to kanamycin, neomycin and tetracycline antibiotics even at a concentration 20 µg ml^-1 indicating that different isolates have different antibiotic resistance pattern and can be used as tool to identify the inoculated rhizobia in soil under unsterilized conditions.