Abstract

Sinorhizobium freddi R0132, which forms nitrogen fixing nodules in association with Vigna radatia L. and fix nitrogen symbiotically, was the bioinoculant used in this study. Drug resistant S. freddi R0132::Tn5 remained constant at 40°C higher levels temperature for about 35 days (5 weeks) from the date of inoculation in solarzied and autoclaved biomanure VC-MA. The Tn5 mutagenesis was carried by the random transposon mutagenesis. The population of drug resistant S. freddiR0132::Tn5 in these treatments was significantly higher as compared to control. The present study attempted to evaluate the role of the said bio-manure VC-MA as carrier for survival of improved drug resistant S. freddi R0132::Tn5 in all the carrier material tested as compared to sample at higher (37 - 40°C) temperature, and higher population of drug resistant S. freddi R0132::Tn5 were observed when stored at relatively lower temperature (28°C). It is therefore not recommended to store the mass culture of biofertilizers particularly at higher temperature.

Key words: Rhizobium, transposon Tn5 mutagenesis, biomanure.