Influence of Nickel and Cadmium Resistant PGPB on Metal Accumulation and Growth Responses of Lycopersicon esculentum Plants Grown in Fly Ash Amended Soil

摘要

Two cadmium- and nickel-resistant plant growth-promoting bacteria, Pseudomonas sp. ASSP 5 and ASSP 29, were isolated from fly ash-contaminated sites, and their plant growth promotion ability was tested by inoculating Lycopersicon esculentum plants grown in fly ash-amended soil. Parameters that were monitored included plant height, wet and dry weights, protein and chlorophyll content in leaves, and concentration of metals in plant root and shoot systems. Although both the bacterial isolates were effective, in most cases, ASSP 29 Pseudomonas sp. exerted a more pronounced effect on plant growth than did ASSP 5. The present observations also showed that both the strains ASSP 5 and ASSP 29 protect the plants against the inhibitory effect of nickel and cadmium, probably due to the production of indole acetic acid and siderophore, and solubilization of phosphate.