Background
Global food production has increased by historic amounts thanks to the Green Revolution of the 20th century. Chemical inputs (pesticides, herbicides, and chemical fertilisers) and better crop plants (achieved through selective breeding and sophisticated genetic engineering) made up the bulk of the Green Revolution. Gains from fertilizer inputs, however, come at a significant environmental cost. To meet the needs for food, fuel, and fiber of a growing global population and a changing environment during the 21st century, a new agricultural innovation revolution will be required. It is necessary for a "Fresh" Green Revolution—possibly the Bio-Revolution—to be built on fewer intensive inputs with less negative environmental impact. Some of the bacteria have evolved into facultative intracellular endophytes as a result of the co-evolution of plants and microbes. PGPR is one of these bacteria that may live freely and has both direct and indirect advantages for plants. In order to increase plant tolerance to biotic and abiotic stress, beneficial rhizobacteria have been used. The mechanism(s) through which soil bacteria display beneficial activities are frequently unclear, despite the fact that, several soil bacteria have been found to support plant growth and development.
Results
The PGPRs viz. RS03 Bacillus subtilis, RS07 Bacillus cereus, RS21 Bacillus mycoides and RS25 Pseudomonas fluorescens were isolated and screened independently and also in possible combinations for evaluation of growth promotion activities in wheat (Triticum aestivum). The growth promotion activity was determined after 50 days of treatment in terms of growth parameters like plant height, shoot dry mass and root dry mass, seedling length and vigor index. Effect of PGPR isolates [sole as well as consortium] shown enhanced effect on germination %, growth and vigor index of wheat plants in comparison to non-inoculated control plants. The consortium application of RS03 + RS07 + RS21 + RS25 showed maximum seedling vigor index followed by the RS03 + RS21 + RS25.
Conclusions
Effect of PGPR isolates [sole as well as consortium] shown enhanced effect on germination %, growth and vigor index of wheat plants in comparison to non-inoculated control plants. The consortium application of RS03 + RS07 + RS21 + RS25 showed maximum seedling vigor index followed by the RS03 + RS21 + RS25.