Isolation of Plant Growth Promoting fluorescent Pseudomonas from Mid-Himalayan Apple Orchards and their Similarity Analysis

Abstract

Ten fluorescent Pseudomonas species isolated from normal and replant rhizosphere soil samples of apple collected from different locations of Shimla and Kullu districts of Himachal Pradesh. These Pseudomonas species solubilized tri calcium phosphate and showed substantial amount of soluble phosphorus in Pikovskay’s broth, exhibited the production of siderophore and growth inhibition against Dematophora necatrix, white root rot causing fungi in apple orchards. Random Amplified Polymorphic DNA analysis was done using four arbitary decamer primers of OPA series to observe genetic homogeneity/polymorphism among 10 isolates of fluorescent Pseudomonas species. Total 25 bands were generated with 4 random decamer oligonuceleotide primers. All the bands generated through RAPD-PCR were polymorphic in nature. The dendrogram constructed using UPGMA method showed that all the ten Pseudomonas isolates were categorized into three distinct clusters. The isolate An-9-Mg and An-H showed maximum similarity (67%) with each other and An-G showed 53% similarity with An-9-Mg and An-H. The isolate Ar-1-Mg was totally different from all other nine strains. Out of the ten Pseudomonas isolates, An-G and An-H showed maximum production of P-solubilization, siderophore and antifungal activity. Therefore, the uniqueness of Pseudomonas isolates An-G and An-H suggested their potential use for developing a cost effective and eco friendly biofertilizers for apple, an important cash crop of Himachal Pradesh.