Tomato genotype and Azospirillum inoculation modulate the changes in bacterial communities associated with roots and leaves.
OBJECTIVE
To evaluate the effect of plant variety and Azospirillum brasilense inoculation on the microbial communities colonizing roots and leaves of tomato (Lycopersicon esculentum Mill.) plants.


RESULTS
Seeds of cherry and fresh-market tomato were inoculated with A. brasilense BNM65. Sixty days after planting, plants were harvested and the microbial communities of the rhizoplane and phyllosphere were analysed by community-level physiological profiles (CLPP) using BIOLOG EcoPlates and denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S rRNA genes. Differences on the rhizoplane and phyllosphere bacterial communities between the two tomato types were detected by principal component analysis of the CLPP; DGGE fingerprints also showed differences at the phyllosphere level. Fresh-market tomato had a more complex phyllosphere bacterial community than cherry tomato, as determined by DGGE profiles. Physiological and genetic changes on phyllosphere and rhizoplane bacterial communities by Azospirillum seed inoculation were evident only on cherry tomato.


CONCLUSIONS
Tomato genotype affects the response of native bacterial communities associated with the roots and leaves to A. brasilense seed inoculation.


CONCLUSIONS
The successful implementation of Azospirillum inoculation requires not only the consideration of the interactions between A. brasilense strains and plant genotypes, but also the plant-associated microflora.
Correa
O S
OS
Cátedras de Microbiología Agrícola, Universidad de Buenos Aires, Av. San Martín 4453, Ciudad Autónoma de Buenos Aires, Argentina. correa@agro.uba.ar
Romero
A M
AM
Montecchia
M S
MS
Soria
M A
MA
D015806:Azospirillum brasilense / Q000502:physiology*; D016172:DNA Fingerprinting / Q000379:methods; D018744:DNA, Plant / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D005516:Food Microbiology; D005838:Genotype; D018551:Solanum lycopersicum / Q000235:genetics / Q000382:microbiology*; D018515:Plant Leaves / Q000382:microbiology; D018517:Plant Roots / Q000382:microbiology; D016133:Polymerase Chain Reaction / Q000379:methods; D025341:Principal Component Analysis; D018749:RNA, Plant / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics
D018744:DNA, Plant; D018749:RNA, Plant; D012336:RNA, Ribosomal, 16S