Ecology, Environment and Conservation Paper

SCREENING FOR PLANT GROWTH PROMOTING PROPERTIES OF ORGANOPHOSPHOROUS PESTICIDE (CHLORPYRIPHOS AND PHORATE) DEGRADING BACTERIAL ISOLATES

R. Gireesh Kumar, A. Vijaya Gopal, R. Subhash Reddy and K. Damodara Chari

Abstract

In the present study sixteen bacterial isolates were isolated from crops like tomato, brinjal maize and Groundnut by the enriched Minimum Salt Medium broth with supplement of chlorpyrifos and phorate source. These isolates were characterized morphologically, cultural and biochemically. Among the eight chlorpyrifos bacterial isolates, CDB-1 showed the high population count at different incubation periods (1st day to 5th day) compared to all CDB inoculates. Similarly eight chlorpyrifos bacterial isolates, PDB-1 showed the high population count at different incubation periods (1st day to 5th day) compared to all PDB isolates. Further these isolates tested for functional plant growth promoting properties like P-solubilization, Indole Acetic acid production, Ammonia production and biocontrol activity (HCN production and Siderophore). The results revealed that among eight CDB Isolates five isolates were able to solubilize phosphate on Pikovskaya’s media containing Tri calcium phosphate in the range of 10 mm to17 mm. Among eight PDB Isolates six isolates were able to solubilize phosphate on Pikovskaya’s media containing Tri calcium phosphate in the range of 10 mm to 25 mm. Among sixteen isolates, CDB-1 is highly IAA producer (+++) followed by CDB-6, CDB-2, CDB-4, PDB-1 were moderate producers (++), CDB-7, PDB-2, PDB-4, PDB-5, PDB-8 were weak producers (+). Out of all sixteen isolates eleven isolates produced HCN. The isolates, CDB-1, PDB-1, isolates produced HCN moderately (++), PDB-2, PDB-4, PDB-3, PDB-6, PDB-8, CDB-2, CDB- 5, CDB-6, CDB-7, were weak HCN producers (+).