Plant Growth Promoting Rhizobacteria: An Alternate Way to Improve Yield and Quality of Wheat (Triticum aestivum)

In this research 198 isolates were collected from native soils of Pakistan and in vitro testing was done for Zn mobilizing activity. Three promising Zn solubilizers namely FA-2, FA-3, FA-4 and their consortium were tested under field conditions with four commercial wheat (Triticum aestivum L.) cultivars viz. Inqlab 91, Chakwal-50, Lasani-08 and SH-2002. A significant increase of 54, 68, 57 and 46% in wheat Zn content over chemical Zn fertilizer was observed under all PGPR treatments. Low increase in grain Zn concentration of 6.5, 7.0, 15.2 and 12.5% was noticed over control by Zn fertilizer treatment with all four wheat genotypes. Various wheat genotypes showed different response with PGPR applications. Similarly, all three strains and their consortium increased wheat grain yield by 2.4, 0.7, 2.2 and 8.6% over chemical Zn fertilizer, respectively. The strains identified by 16S rRNA, gyrB and gyrA gene analysis were Serratia liquefaciens, S. marcescens and Bacillus thuringiensis. The present findings show that enhanced rate of PGPR colonization can improve grain yield and Zn content of wheat as compared to chemical Zn fertilizer. Co-inoculation of PGPR proved to have more potential of Zn mobilization towards grain. Maintaining suitable density of Zn mobilizers in the soil through field inoculation might be a promising strategy to enhance grain yield and Zn content of wheat. Commercial field application of this approach among farmers is recommended. (C) 2015 Friends Science Publishers