H2-oxidizing, plant growth promoting rhizobacteria as seed inoculants for barley

Abstract

The persistence of allegedly inefficient hydrogenase uptake negative (HUP⁻) legume-rhizobia associations may be accounted for by the beneficial effects of hydrogen release to soil, including the stimulation of H₂-oxidizing, plant growth promoting rhizobacteria (PGPR). Two such previously isolated strains were tested as seed inoculants for barley; there were significant differences between treatments and controls in tiller and grain head production, supported by data from greenhouse trials. TRFLP analysis of barley soil samples, supported by DNA sequencing data, successfully distinguished both species of PGPR and successful re-isolation shows that these isolates can reproduce themselves in soils and so can be used as effective inoculants with peat as the standard carrier. The development of PGPR as seed inoculants is an important step towards sustainable agriculture.