, Volume 14, Issue 3, pp 185–192 | Cite as

Impact of two fluorescent pseudomonads and an arbuscular mycorrhizal fungus on tomato plant growth, root architecture and P acquisition

  • Elisa GamaleroEmail author
  • Antonio Trotta
  • Nadia Massa
  • Andrea Copetta
  • Maria Giovanna Martinotti
  • Graziella Berta
Original Paper


The ability of fluorescent pseudomonads and arbuscular mycorrhizal fungi (AMF) to promote plant growth is well documented but knowledge of the impact of pseudomonad-mycorrhiza mixed inocula on root architecture is scanty. In the present work, growth and root architecture of tomato plants (Lycopersicon esculentum Mill. cv. Guadalete), inoculated or not with Pseudomonas fluorescens 92rk and P190r and/or the AMF Glomus mosseae BEG12, were evaluated by measuring shoot and root fresh weight and by analysing morphometric parameters of the root system. The influence of the microorganisms on phosphorus (P) acquisition was assayed as total P accumulated in leaves of plants inoculated or not with the three microorganisms. The two bacterial strains and the AMF, alone or in combination, promoted plant growth. P. fluorescens 92rk and G. mosseae BEG12 when co-inoculated had a synergistic effect on root fresh weight. Moreover, co-inoculation of the three microorganisms synergistically increased plant growth compared with singly inoculated plants. Both the fluorescent pseudomonads and the myco-symbiont, depending on the inoculum combination, strongly affected root architecture. P. fluorescens 92rk increased mycorrhizal colonization, suggesting that this strain is a mycorrhization helper bacterium. Finally, the bacterial strains and the AMF, alone or in combination, improved plant mineral nutrition by increasing leaf P content. These results support the potential use of fluorescent pseudomonads and AMF as mixed inoculants for tomato and suggest that improved tomato growth could be related to the increase in P acquisition.


Pseudomonas fluorescens Glomus mosseae Mixed inoculum Root architecture Phosphorus acquisition 



We wish to thank Dr. Guido Lingua for critical reading of the paper, and Dr. Lorena Avidano and Dr. Barbara Pivato for technical support and stimulating discussions. We are grateful to Dr. Alberto Escande (Instituto Nacional de Tecnologia Agropecuaria, Balcarce, Argentina) for providing the P. fluorescens strain P190. This work was supported by MIUR.


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Copyright information

© Springer-Verlag 2003

Authors and Affiliations

  • Elisa Gamalero
    • 1
    Email author
  • Antonio Trotta
    • 2
  • Nadia Massa
    • 1
  • Andrea Copetta
    • 1
  • Maria Giovanna Martinotti
    • 3
  • Graziella Berta
    • 1
  1. 1.University of Eastern Piedmont "Amedeo Avogadro"Department of Science and Advanced Technology AlessandriaItaly
  2. 2.Department of Plant BiologyUniversity of Turin TurinItaly
  3. 3.Department of Chemical Alimentary Pharmaceutical and Pharmacological ScienceUniversity of Eastern PiedmontNovaraItaly

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