Nidhi Srivastava
H.N.B. Garhwal University, Srinagar, Uttarakhand
Title: Diversity and function of rhizobacteria isolated from Zanthoxylum armatum Dc.
Biography
Biography: Nidhi Srivastava
Abstract
Zanthoxylum armatum DC is an endangered medicinal plant, used in toothache, stomachache, diarrhea etc. Rhizosphere is a rich niche of microbes and should be explored for obtaining plant growth promoting rhizobacteria (PGPR), which enhance the growth of the plant either directly or indirectly. A total of 144 rhizobacteria were isolated from rhizospheric soil of Z. armatum DC. A total of 12 different genera were identified. A total of 29.17% were Bacillus followed by Pseudomonas (21.53%), Klebsiella, Micrococcus (6.25%) each, Staphylococcus, Azotobacter, Flavobacterium and Serratia being 4.86% each, Xanthomonas (3.47%), Alcaligenes and Enterobacter (2.78%) each and Azospirillium (0.69%). Bacillus was dominant in rhizosphere of Z. armatum followed by Pseudomonas sp. All isolates were tested for PGPR properties. A Total of 67.36% isolates were found to be positive for IAA production. These isolates produced IAA ranged between 0.693±0.83µg/ml to 73.41±1.95µg/ml. Highest IAA was produced by Pseudomonas sp. (S3KS8) from Site-3 while lowest IAA was produced by Micrococcus sp. (S3UW3) from Site-3. A total of 46.53% isolates were found to be positive for phosphate solubilization. These isolates solubilized phosphate ranging from 21.4±1.02% to 309.1±1.63%. Highest phosphate was solubilized by Bacillus sp. (S2DS7) from Site-2 and lowest by Serratia sp. (S3UR1) from Site-3. Another important trait of PGPR, that may indirectly influence the plant growth, is the production of ammonia. A total of 63.19% isolates were found to be positive for ammonia production. Among them 32.61% rhizobacteria produced high amount of ammonia followed by 42.39% moderate and 25.0% generated low amount of ammonia.