Characterization of indole acetic acid endophyte producers in authoctonus Lemna gibba plants from Xochimilco Lake

Abstract

Xochimilco’s lacustrine zone is a network of channels that, along with the chinampas, conform a unique ecosystem which has served as source of aquatic resources. Duckweeds are small free-floating monocotyledon aquatic plants classified as macrophytes that serve as nutrient pumps and reduce eutrophication effects. Recently, there are number of new studies related to the aquatic plant-microbial interaction focused on the direct functional analysis that investigate plant microbe interactions at full biological hierarchy. The aim of this study was to compare the auxin in vitro production efficiency of the endophyte phytobacteria isolated from Lemna gibba L. plants collected nearby the Xochimilco aquatic agrosystem. There were 17 isolates obtained from the L. gibba plants collected in the dry season and 14 isolates for the rainy season. The environmental conditions and seasonal characteristics determined the number and identity of the isolated endophyte phytobacteria in L. gibba plants according to the several apparent differences in the water quality. This work contributes to the knowledge of the phytobacteria diversity in aquatic plants, particularly in Lemnaceae species; here the majority of the isolates have been characterized as higher indole acetic acid producers, recommended as candidates for their use as biofertilizers.

Key words: Plant growth-promoting bacteria, biofertilizers, Lemna gibba, Xochimilco.