Abstract

PCR based DNA finger printings were performed by ISSR primers, gene specific primers (Plt) and primers derived from 16S ribosomal RNA. Fifteen primers pairs were used to detect the polymorphism between 45 isolates of Pseudomonas spp. Results revealed that clear polymorphism and similarity coefficient ranged from 0.00 to 0.44 with ISSR primers, 0.01 to 0.83 with gene specific primers and 0.22 to 1.00 in with 16S ribosomal RNA specific primers. No correspondence was observed between the ISSR based clustering and pyocinin and fluorescine expression. Individual cluster grouped different types of isolates irrespective of their expression for pyocyanin, fluorescein or siderophore production. Dendrogram generated by Plt (gene specific primer) based DNA finger printing revealed that four set of gene specific primer were screened on 45 isolates to identify the primer that produce the polymorphic fragment. The isolates shows clearly scorable polymorphism and similarity coefficient ranged from 0.01 to 0.83. DNA amplicons from all isolates differences in the molecular weight of the amplified product only formed similarity groups in subsequent sub-sub- clustering. Dendrogram generated by primers from 16S ribosomal RNA revealed that two set of 16S ribosomal RNA specific primer were screened on 45 isolates to identify the primer that produce the polymorphic fragment. The isolates show clearly scorable polymorphism and similarity coefficient ranging from 0.22 to 1.00. The isolates (P6, P76, P113, P82, P195, P136, P196, P20, P224, P133, P223, P14, P155 and P98); (P9, P16, P85, P70, P109, P217 and P144); (P16, P57, P98, P59, P138, P85, P179 and P184) formed different clusters but had no correspondence with the pigment production or biochemical tests.

Key words: Pseudomonas spp., genotyping fingerprinting.