Screening and Characterization of Multi-Trait Plant Growth Promoting Bacteria Associated with Sugarcane for Their Prospects as Bioinoculants

Abstract

Plant growth promoting bacteria has become of great interest to promote the crop growth and protect from phytopathogens. Total of 100 bacterial isolates were obtained form 45 different samples of rhizosphere soil as well as sugarcane parts. After extensive screening, eight isolates found as potential for multiple PGP traits were further investigated for cellulase, chitinase, HCN production potential and antifungal activity. Isolates F271 and F373were found to produce chitinase. HCN production was found in only F323 isolate. Secondary screening was carried based on quantitative abilities to select the most efficient multiple PGP isolates. IAA production was found higher in F271 isolate (93.69 mg L-1) followed by F181 and F373 isolates. Phosphate solubilization was found higher in F373 isolate (15 mg L-1) followed by FF271, ESB4 and F181. More than 90 % unit of siderophore activity was found in all isolates under study except the ESB4. Protease production was found higher in F181 isolate (19.5 IU), while other three isolate FF271, ESB4 and F7373. Chitinase activity was found 0.35 IU in F271 isolate while F373 was also found to produce 0.2 IU chitinase. Based on these results of screening three isolates F181, FF271 and F373 which shows multi-trait PGP activity isolated from the different agro condition and popular varieties of sugarcane are selected for further study. Characterization of these selected isolates identifiesF271 and F373 isolates as species of Pseudomonas. While, isolate F181 was tentatively identified as Bacillus spp.