Standardization of the Protocol for Screening and Evaluating Phosphorous Solubilizing Activity of Native Trichoderma and Other Microbial Strains

Abstract

Thesis Title: "Standardization of the protocol for screening and evaluating phosphorous solubilizing activity of native Trichoderma and other microbial strains." Advisor: Dr. Akash Tomar The applied phosphorus in the soil is not available directly to the plants, it has to be solubiJ ized by the various microorganisms present in the soil. Only then it mixes with the soil water and grabbed by the plant as the solution. Various isolates of Trichoderma, Aspergillus and Pseudomonas are ubiquitous and are relatively easy to isolate and culture. Trichoderma and Pseudomonas, genus of fungi and bacteria, respectively are widely present in soil and have the ability to act as biocontrol agents against plant pathogens and to solubilize the micronutrients present also in the soil. In the present investigation phosphate solubilizing capability of native Trichoderma spp. and other microbial strains has been studied on optimized medium. A total of 02 Trichoderma strains (TPI and SPTI), (J 1 Aspergillus (A 1) and 03 Pseudomonas bacterial strains designated as P2, P4 and PI 0, were isolated from six soil samples which were belongs to Viii. Siwaya Central Potato Research Institute (CPRI) and Viii. Bafawat, Meerut respectively. Morphological study showed that these strains are similar to that of Trichoderma harzianum. Growth kinetics study showed that the stra in SPTI fast growing isolate as compare to isolate TPI. The strains of Pseudomonas produced fluorescence under transilluminator on King'B medium and identified on the basis of their fluorescence. Gram staining sho\ved that these are Gram negative bacterial strains. Growth kinetics study showed that the Pseudomonas bacterial strain P4 was fast growing as compare to other two strains. Genomic DNA was isolated from the isolates of Trichodern1a and Pseudomonas for molecular characterization on the basis of ITS I and ITS4 marker for their I 8S region and 16S region of the rONA respectively. The ITS sequencing of 07 Trichoderma strains showed 06 of them to be harzianum and phylogenetic analysis classified them in three clades. The PVK medium supplemented with Methyl red was best for visualization of pH reduction and halo zone produced by PSM. A total of 67 microbial strain, 61 different Trichoderma isolates which were collected from Department of Recombination Techniques & Pl. Pathology, 01 Aspergillus strain, 01 Yeast, 0 1 Fusariun1 moniliforme and 03 Pseudomonas strains were used to evaluate their phosphate solubilization activit) on optimized PVK media. A total of 19 strains showed phosphate solubilization activity and formed clear halo zone around the inoculum that indicate phosphorus solubilization in PVK mediurn. The efficiency of strain in solubilizing Index and Efficiency (SI/ SE) was in following order (Pseudo1nonas P2>P4>P 1 0> Aspergillu AspA 1> Trichoderma Sug-6>S-4l>S-47>S30). A total of 10 of these strains were evaluated for P solubilization in PVK broth culture and estimation of P solubilization was done by Chlorostannous Method. The best strain .. solubilizing phosphorus on basis of Solublization at 4 day are (Pseudomonas P2>P4>P 1 0> Trichodenna SJ2>S27>S 11> Aspergillus AspAI> S47>S30>Si-16) and at 8 Day as (Pseudornonas P2>P4>P.I?~ Asp~r~ill~t · AspA 1> Trichoderma s27>S 11>S32>S47>s30 and Si-16). The results showed differing P solubtltztng abdtt) tn Solid and Liquid medium condition by microbial strains. These microorganisms may ha~e an inlportant a~ld differing role in phosphate solubilization in soil and these studies may be conducted 10. futur~. Also With optimization of screening and soluble P estimation more microorganisms may be tested for thetr effictency.