Impact of Flyash on Plant Growth Promoting Activity of Cyanobacteria

Abstract

Anabaena variabilis (ARM441), Aulosira fertilissima (ARM444), Nostoc muscorum (ARM442), Tolypothrix tenuis (ARM443) procured from IARI, New Delhi were studied for plant growth promoting activity such as Indole acetic acid production, Nitrate reductase assay and phosphate solubilization. Among four cyanobacterial strains Aulosira fertilissima (ARM 444) showed maximum Indole acetic acid (0.050µg/ml) in the presence of tryptophan (1mgml), Nitrate reductase activity (0.543mg/g), biomass production (2.12mg/ml), solubilisation of tricalcium phosphate (5.86ppm) and chlorophyll content (0.35mg/ml ), whereas Nostoc muscorum (ARM 442) showed least plant growth promoting activities. Effect of fly ash at different concentration (0, 1, 2, 5, 10 and 20%) on growth and PGP activity was studied on Anabaena variabilis (ARM441) and Aulosira fertilissima (ARM 444) and it was revealed that 10% fly ash (w/v) in BG-11 medium showed maximum plant growth promoting activity, Nitrate reductase activity, Indole acetic acid production and solubilization of phosphorous and dry biomass production. At higher concentration (20%) of fly ash there was decline plant growth promoting activity.