IDENTIFICATION AND QUANTIFICATION OF WHEAT ROOTS FLAVONOIDS INOCULATED WITH NATIVE RHIZOBACTERIA

Abstract

In this study, we identified the presence and quantity of flavonoids produced in wheat roots inoculated with rhizobacteria. Our goal is to confirm the efficiency of standard isolates and show new strains with biotechnological potential to promote plant growth. The experiment was carried out with different isolates under inoculation in the following situations: T1-Azospirillum brasiliense; T2-Herbaspirillum seropedicae; T3-Azospirillum brasiliense and Herbaspirillum seropedicae co-inoculation; T4-native Enterobacter sp. nº 203; T5- native Enterobacter sp. nº 208; T6-native Enterobacter sp. nº 493; T7-Control only under nitrogen fertilization (N+); T8-Control without nitrogen (N-) and bacterial inoculation. Agronomic characteristics were assessed after 42 days of inoculation. Identification and quantification of flavonoids were carried out through HPLC, using an analytical curve with four standards based on Coumarin, Quercetin, Isoflavone and Rutin. Regarding the production of total flavonoids, two (203 and 493) out of the three native strains we tested were statistically significant, exceeding the values obtained from the inoculation of standard strains, which presented association with grasses (Azopirilum e Herbaspirillum). Standard bacteria, when inoculated in isolation, presented, along with those that received N+ treatment, the highest values for length and root and aerial part dry mass. New studies need to be carried out in order to confirm the technological use of these native strains as inoculant, as these bacteria may contribute to Biological Nitrogen Fixation (BNF) in wheat culture, either by competition or synergism.