Peanut and maize growth stage affects the rhizobacterial community structure

ANZUAY, MARIA S.; PIN VISO, N; LUDUENA, L.; MORLA, F. ; ANGELINI, J.; TAURIAN, TANIA

Simposio; XVI Symposium on Biological Nitrogen Fixation with Non- Legumes, together with the IV Latin-American workshop on PGPR and the XIX RELARE; 2018

Peanut (Arachis hypogaea L.) is an economically important leguminous crop in Argentina. The rotationof peanut with other crops, especially cereal crops is crucial to obtain a good yield. In the agricultural areaof Argentina, maize (Zea mays L.) is the main cropused in rotation with peanuts. Rizosphere bacteriacan exert beneficial effects on plant growth grow and development by releasing nutrients into the rizosphere. This soil area is a versatile and dynamic ecological environment of intense microbe plant interactions andthe rhizobacterial communities can be affected by awide range of factors including environmental factors such us soil type and plant species. Considering the importance of peanut and maize crops, in the objective of this study was to analyze bacterial community structure associated with the phenological stages of these plants. For this, a microcosm assay was performed using soil from the peanut growing area of Argentina as plant growth support. Unsterile soil was placed in plasticpots and previously peanut and maize disinfected seeds were sown. Plants were maintained under controlled environmental conditions during 120 and 100 days for peanut and maize respectively. For bacterial rizhosphere analysis, soil samples were taken at the beginning ofthe assay for both plants and at 60 and 120 days for peanut and at 40 and 100 for maize. Soil DNA from these samples was extracted using a commercial kit. Bacterial community structure of soil rizosphere was analyzed by high-throughput sequencing of 16S rRNA gene (Illumina MiSeq platform). Results obtained indicated that the most abundant phyla, in both peanut and maize rizosphere were Proteobacteria, Acidobacteria, Actinobacteria and Bacteroidetes. Rhizobacterial community structures were different depending on plant species and significant changes were observed through plant growth stages at diverse taxonomic levels (phylum, family and genus).The most significant differences were observed on the rizosphere of late plant growth stages. In conclusion,the structure of the rhizospheric bacterial community is dynamic and is influenced by phenological plant growth stage.