Influence of Fertilizer Level on Establishment of LacZ Tagged Mutants of Pseudomonas Striata in Soybean Rhizoshpere

Abstract

The fates of Pseudomonas striata(P-27) and its mutant were compared in the rhizosphere of soybean at different fertilizer level. Three lacZ tagged mutant strains designated as superior, inferior and homologous to parent with respect to P-solubilization (T-80, T-128, T-125) and IAA production (T-49, T-57, T-87) wer e selec ted for establishment studies. The comparison of mutants for their ability to survive and establishin soybeanrhi zosphere revealed, a linear decline of the population with plant growth period. Individual potexperiments were onducted with superior strains to study the nfluence of level of fertilizer on phosphobacterial population in rhiz osphere and crop growth. It is concluded that inoculation of P. striata strain increases the population of phosphobacteria and growth parameters of soybean irrespective of the level of fertilizer.The application of fertilizer beyond 50% of the recommended dose was found to be relatively unresponsive.