Efficacy of bacterial seed treatments for the control of Fusarium verticillioides in maize

PEREIRA, P.; NESCI, A.; ETCHEVERRY, M.

BIOCONTROL (DORDRECHT)

Springer

Lugar: Netherlands; Año: 2009 vol. 54 p. 103 - 111

1386-6141

Since maize colonization by the phytopathogenic fungi Fusarium verticillioides leads to economical and food quality losses and also implicates health potential risks, different strategies for the control of this fungal species are seriously being taken into account.  In the present work we investigated the in situ effects of the use of two in vitro proven bacterial biological control agents against Fusarium verticillioides, using maize seedlings grown in greenhouse conditions. The treatment of maize seeds with Fusarium verticillioides 107 sp ml-1 negatively affected some seedlings growth parameters and promoted a significant reduction in the non-rhizospheric numbers of organisms with ammonification and nitrification activities. The addition of Bacillus amyloliquefaciens Ba-S13 or Microbacterium oleovorans DSM 16091T, at a concentration of 109 colony forming units ml-1, to the seeds significantly reduced Fusarium verticillioides count at the root inner tissues of resultant seedlings. When testing the impact of bacterial treatments on soil populations, no alterations with respect to control numbers of organisms with nitrification, ammonification or cellulolytic potentials were observed. Culturable bacterial richness and diversity calculated at the rhizoplane and root inner tissues of maize seedlings neither changed in bacterized treatments when compared to control treatment. Our study showed that the Fusarium verticillioides in vitro  proven antagonists, Bacillus amyloliquefaciens Ba-S13 and Microbacterium oleovorans DSM 16091T (at 109 colony forming units ml-1), were also effective at greenhouse conditions with no negative impact on culturable maize rhizospheric and endophytic microbial richness and diversity.