Abstract
Agricultural chemicals enter in the soil through various sources, which affect the microorganisms and microbial processes important for plant growth and soil health. Incorporation of resistance against agricultural chemicals in rhizobium specie is a simple and sustainable technique to identify inoculated strains. Seventeen strains grew well in herbicides (100-micro g g-1) and insecticides (100-micro g g-1). Bactericides and fungicides registered the lethal effect on Rhizobium legumiosarum phaseoli strains. The concentrations \ more concentrations (Bactericides 15 and 20 micro g g-1 and fungicides 60,70,80 and 90 micro g g-1 and their combinations (15+60 and 15+70 micro g g-1) proved to be lethal for growth of Rhizobium leguminosarum phaseoli, during intrinsic resistant study, were selected to incorporate marker strains. Different strains had different type of resistance against these agricultural chemicals. Symbiotic properties of the entire agricultural chemical resistant mutant were studied under controlled conditions. Three strains of Rhizobium legumiosarum phaseoli lost the capacity to infect its hosts after acquiring resistance against agricultural chemicals and the remaining seven formed nodules in their specific host. Four agricultural chemical resistant mutants isolated from namely F H PM-1, F H PM-2 F H PM-4, and F H PM-5 were found to be consistently superior to their wild type parents. While rest three of strains i.e. F H PM-3, F H PM-6 and F H PM-7 were consistently inferior to their wild type parents
