Effect of plant growth promoting rhizobacteria on seed germination and growth of wheat plants

Abstract

Abstract : Plant growth promoting rhizobacteria (PGPR) are recognized as important agents for stimulating growth of various plants. The present study was undertaken to explore the potential of two PGPR strains, namely Pseudomonas stutzeri PPB1 and Bacillus subtilis PPB2 to promote seed germination, plant growth, and leaf nitrogen content in four wheat varieties, namely Kanchan, Shatabdi, BARI Gom-27, and BARI Gom- 29. Both the strains significantly increased (18.20 to 21.28%) seed germination in var. Shatabdi compared to un-inoculated control, while in var. BARI Gom-27 and BARI Gom-29, the significant increase in seed germination was observed in treatment with B. subtilis. Treatment with both the strains resulted in significant increase in shoot length (16.54% to 44.11%), shoot fresh weight (21.17% to 85.48%), shoot dry weight (29.54% to 110.22%), root length (16.71 to 58.81%), root fresh weight (17.79% to 93.06%-) and root dry weight (21.42% to 77.78%) of wheat plants compared to un-inoculated control. Both the PGPR significantly enhanced leaf nitrogen content (27.17% to 73.78%) in wheat plants of four varieties. The two tested rhizobacteria colonized the wheat roots successfully accounting a population with a range of 73.50x 107 to 233.60 x 107 cfii/g root tissue. Two PGPR strains varied in effectiveness in stimulating plant growth traits. Higher plant growth promotion was obtained in plants pretreated with B. subtilis than with P. stutzeri. Application of selected PGPR inoculants, thus, could be an obvious approach to reduce the use of chemical fertilizers in wheat field.