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Evaluation of a new innovative method of increasing soybean yields through inoculating seeds or emergent plants with seed-dwelling cytokinin producing Methylobacterium

Principal Investigator

Neil Emery

Research Institution

Trent University

External Funding Partners

Trent University; Industry partners

Project Start

March 2013

Project End

October 2015


  • Screen plant endophyte Methylobacterium from international collections for the ability to synthesize high levels of cytokinins (CK; a class of plant growth regulators).
  • Inoculate soybeans at different developmental stages with selected endophytic strains.
  • Determine the most effective treatments of endophytes in greenhouse and field trials and observing effects on yield and important growth parameters.


  • The improvement of soybean yield through increased fruit setting.
  • The enhancement of the beneficial Methylobacterium population that naturally stimulate plant growth and can help limit the impact of pathogenic microbes.
  • The reduction of fertilizer use through the inoculation of soybean with the growth promoting Methylobacterium.
  • The identification of the most active Methylobacteria can facilitate development of effective biostimulators for use in the cultivation of diverse crop and vegetable species.

Scientific Summary

In legumes and cereals, cytokinins have been shown to play a role in improving yield. It has been recently discovered that certain seed dwelling bacteria, part of a group of symbiotic bacteria beneficial to plants called endophytes, could play a significant role in the production of cytokinins in plants and their seeds. Methylobacterium is an endophyte. Methylobacterium have a rare characteristic of producing plant growth hormones called cytokinins. Cytokinins (CKs) are a vital class of plant growth hormones responsible for regulation of growth and development of reproductive organs through stimulating flowering, fruit set and seed filling. While plants are considered to be self-efficient producers of plant growth hormones, plant endophytes have been show to produce plant growth hormones and influence the hormonal balance of their hosts.

To improve crop productivity and soybean yield through the manipulation of plant-associated microorganisms, it was important to identify effective strains of Methylobacterium. A diverse collection of Methylobacterium strains was analysed for CK production and the most active Methylobacteria were used for inoculating soybeans. The performance of the inoculated and control plants (not inoculated with Methylobacteria) was analysed on 3-week old seedlings in the greenhouse trials. The strain that enhanced plant performance most significantly was selected for use in field trials. Different techniques of bacterial treatments were tested to determine the most effective way of bacterial delivery to plants, including seed inoculation, soil application after planting, and spraying at early seed setting stage. To further validate the performance of Methylobacterium, trials included comparisons with commercially available rhizobial bioinoculants. The results pointed to a positive effect of Methylobacterium on soybean growth and the highest number of podded plants was observed for Methylobacterium-inoculated soybeans compared to the untreated controls and soybeans treated with existing commercial inoculants. The final outcomes of the project indicate good potential for the use of selectable, high performance Methylobacterium as a crop bioinoculant to improve yield and reduce fertilizer requirements.

Project Related Popular Publications

Harnessing the power of nature. Beneficial Bacteria Boosts Soybean Yields. Jeanine Moyer, Ontario Grain Farmer, February 2016 (Link)

Using good bacteria to grow more crops. Lilian Schaer, AgInnovation Ontario, May 2016 (Link)

How freak bacteria could help feed the world. Exceptional microbes are being harnessed in the development of new bio-fertilizers. Jonathan Forani, Toronto Star, May 2016 (Link no longer available)