Plant growth promotion by four species of the genus Burkhoderia

Abstract

The genus Burkholderia is highly diverse and may mediate plant growth via several mechanisms. The current study evaluates the role of strains from four Burkholderia species in maize growth promotion. Twenty three strains of diazotrophic Burkholderia species were applied to two maize genotypes (SHS5050 and BRS4157) under greenhouse and field conditions. Strains were tested for growth promotion in greenhouse during 40 days. Strain 41 from B. silvatlantica was used under field conditions. Parameters evaluated: biomass accumulation, N and root measurements in pots and grain yield, N % and N in the grains under field conditions. Eleven strains were evaluated under soil substrate. The inoculation of the hybrid SHS5050 showed root biomass improvement using three strains, namely M130, M209 and PPe7. The highest acetylene reduction activity was observed in strain 41 from B. silvatlantica. Strain 41 from B. silvatlantica improved plant dry mass on both genotypes. This strain produced 31 % more aerial tissue and 7 % more root dry mass in the BRS4157 variety than it did in the control. Both genotypes planted at Seropedica, RJ, produced 7 % more grains under field conditions and the variety produced 10.9 % more grains in comparison to the non-inoculated control. Strain 41 from B. silvatlantica showed beneficial plant-growth promotion of maize under greenhouse and field experiments specially in a low fertility soil.