Effect of potassium and ammonium nitrate media on in vitro growth response of potato (Solanum tuberosun L.)

The Pseudomonas fluoruescens Migula is a well known soil borne and non pathogenic biological control agent. P. fluorescens has been found to show inhibition to the phytopathogens of Rhizoctonia solani Kuhn, Bipolaris oryzae Shoemaker, Cochliobolus lunatus Nelson, Alternaria brassica Berk, Aspergillus niger Van Tiegh, Fusarium oxysporum Schlechtendal and Trichothecium roseum Link. The antagonistic activity of the crude extract was studied by duel plate and poison plate assays. This results proved that the crude extract have antagonistic potential against fungal pathogens. The crude extract was purified by Thin Layer Chromatography (TLC) and showed the different coloured bands under Ultra Violet (UV). These crude antibiotic substance is also effective against the spores germination of phytopathogens that studied by spore germination assay. The strain improvement was also carried out on the nitrogen fixer Rhizobium species De Lajudie, using plasmid DNA transformation technique. The plasmid DNA from P .fluorescens was transformed to competent cells of Rhizobium species and the transformations was obtained and showed both biological control.