Efficacy of Burkholderia cepacia MCI 7 in disease suppression and growth promotion of maize

Abstract

Repeated greenhouse experiments were performed to evaluate the ability of a maize-rhizosphere isolate of Burkholderia cepacia, applied as a seed coating, to promote maize growth in both uninfested soil and soil infested with a maize pathogenic strain of Fusarium moniliforme, and to displace or negatively affect the population of F. moniliforme throughout plant growth. Results demonstrated that the B. cepacia strain MCI 7 is a promising plant-growth-promoting inoculant for maize. In repeated greenhouse trials, bacterization of maize seeds with B. cepacia MCI 7 resulted in a significant (P<0.05) increase of maize plant growth in both uninfested soil and soil infested with F. moniliforme ITEM-504, as compared to uninoculated plants. Moreover, B. cepacia MCI 7 was able to negatively affect the rhizoplane colonization of F. moniliforme that showed significantly (P<0.05) lower values of population density throughout plant growth, as compared with respective values observed in the root system of uninoculated plants. The effect on plant growth following introduction of B. cepacia MCI 7 into the maize rhizosphere has also been investigated using two corn cultivars differing in their degree of resistance to Fusarium. Results showed that B. cepacia MCI 7 was able to determine an increased growth response (P<0.05) of the two corn cultivars in both uninfested soil and soil infested with F. moniliforme.