RAPD Analysis of Phosphate Solubilizing Fungi and rDNA Gene Sequence based Phylogeny of Talaromyces flavus

摘要

A large number of phosphate solubilizing fungal isolates (PSFs) were obtained from different areas of North Bengal. Out of this collection, four isolates of Talaromyces flavus, four each of Aspergillus niger and A. melleus as well as three of A. clavatus were found to solubilize phosphate to a greater extent when quantified for rock phosphate and tricalcium phosphate solubilization in vitro. Genetic relatedness among these phosphate solubilizing fungal isolates was determined using random decamer primers. UPGMA cluster analysis based on the RAPD banding partem showed similarity coefficient ranging from 0.17 to 1. The similarity coefficient was also represented by two and three dimensional plots which showed the genetic relatedness among the PSFs. Phylogenetic analysis of T. flavus (RHS/P-51)- a more efficient phosphate solubilizers was carried out by sequencing the internal transcribed spacer regions (ITS 1 and ITS 4) of the ribosomal DNA using universal primers. The sequences were aligned againstex-type strain sequences from NCBI GenBank for identification. The open reading frame (ORF) analysis of 565 residue sequence designated as 18S rRNA gene, partial sequence of T. flavus revealed that the sequence contains a total of two ORFs encoding 84 amino acids with an estimated molecular mass of 17.12 kDa.