IN INOCULANTS Nodulaid - 17th International Nitrogen Fixation ...

17 th International Congress on Nitrogen Fixation
Fremantle, Western Australia
27 November – 1 December 2011
Title Protection of plant health by Micromonospora isolated from alfalfa root nodules.
Authors Pilar Martínez-Hidalgo 1,3 , Pablo García-Benavides 2 ,José Maria Díaz-
Mínguez 1 , Ernesto Pérez Benito 1 , Martha E. Trujillo 1, and Eustoquio
Martínez-Molina 1 .
Poster Board Number 39
1 Departamento de Microbiología y Genética, Universidad de Salamanca
2 Departmento de Construcción y Agronomía, Universidad de Salamanca
3 GIR "Interacciones mutualistas planta microorganismo", Unidad
Asociada al IRNASA. CSIC,
The studies of new interactions that allow us to design efficient biofertilizers, to reduce the use of pesticides and
chemical fertilizers are very important nowadays. The endophytic actinobacteria have a very high
biotechnological potential in agriculture and environment. The activity of endophytic actinobacteria can affect (A)
the development of plants in a direct way (B) their nutrition, making it easier to get essential elements like
nitrogen, iron or phosphore (C) the health of the plants by means of direct mechanisms, like antibiotic or
siderophore synthesis or inducing plant defence responses and (D) improving adverse environmental factors
tolerance.
In this work we study the PGPR effect of actinobacteria from Micromonospora genus that were isolated from
alfalfa nodules. Strains that promote plant growth, improve nutrient uptake and nodulation were selected. The
selected strains were used, in this work, for studies focused on the protection of plants from pathogens.
Protection of plant health by means of direct mechanisms,
In vitro studies of growth inhibition of plant pathogens: The following plant pathogens were used for this study:
Fusarium circinatum, Sclerotinia sclerotionum, Botrytis cinerea, Rhizoctonia solani, Clavivacter miichiganensis,
Erwinia amylovora, Pectobacterium chrisanthemi, Pseudomonas syringae pv. pisi, Pseudomonas syringae pv.
syringae, Ralstonia solanacearum, Xanthomonas vesicatoria
Micromonospora strains were tested for siderophore production on CAS medium.
Protection of plant health by induction of plant defence responses: These studies have been performed on tomato
plants using two Micromonospora strains (ALFb5 and ALFpr18c) and two plant pathogens: Botrytis cinerea and
Fusarium oxysporum
The results obtained point out that the selected strains of Micromonospora may be used to protect plants from
pathogens. (i) Some of the tested strains inhibit fungal growth in vitro. (ii) No effect was detected against the
tested bacteria. (iii) Many of the strains tested produce siderophores. (iv) Micromonospora induces plant defence
response.
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2011