In Vitro Antagonistic Potential Of Endophytic Bacteria Against Burkholderia Glumae

Abstract

Burkholderia glumae is the etiological agent of the disease called bacterial blast of the rice panicle, which causes great economic losses in the agricultural sector. The objective of this research was to evaluate the antagonistic activity in vitro of endophytic bacteria isolated from rice varieties against Burkholderia glumae. A completely randomized design was applied for in vitro antagonistic activity between endophytic bacteria against B. glumae and to differentiate between the population density present in rice varieties and type of colonized tissue. Likewise, the Duncan range multiple test was used to establish statistically significant differences (p-value < 0.05) between colonized tissues and percentage of inhibition of endophytic bacteria. We isolated 148 morphotypes of endophytic bacteria of the varieties F2000, FMocarí and F473. The variety F2000 had a higher population density (p-value < 0.05). The root was the tissue that presented the highest population density of endophytic bacteria (p-value < 0.05) when compared to the rest of the tissues. The morphotypes

H2M1LIM and P4M2LIM identified molecularly by the 16S rRNA gene as Burkholderia cepacia, R1M2LIM and R3M3LIM as Bacillus subtilis and T5M7 as B. cereus which presented in vitro inhibition against B. glumae. These species are characterized by producing volatile and non-volatile secondary metabolites that have the ability to control growth in vitro against pathogens. The application of endophytic bacteria with antagonistic potential can become in the future a great alternative to replace the application of agrochemicals and chemical fertilizers.