European Journal of Plant Pathology

, Volume 117, Issue 2, pp 109–122

Induction of a defense response in strawberry mediated by an avirulent strain of Colletotrichum

Article

DOI: 10.1007/s10658-006-9075-7

Cite this article as:
Salazar, S.M., Castagnaro, A.P., Arias, M.E. et al. Eur J Plant Pathol (2007) 117: 109. doi:10.1007/s10658-006-9075-7

Abstract

In the strawberry crop area of Tucumán (north-west Argentina) the three species of Colletotrichum causing anthracnose disease (C. acutatum, C. fragariae and C. gloeosporioides) were detected. Among all isolates characterized, one of them identified as C. acutatum (M11) and another as C. fragariae (F7) were selected due to their conspicuous interaction with the strawberry cultivar Pájaro. Whereas isolate M11 produced a strong compatible interaction in cv. Pájaro with clear disease symptoms (DSR = 5.0), the isolate F7 brought about a typical incompatible interaction (DSR = 1.0). When plants of cv. Pájaro were inoculated with F7 prior to the inoculation with M11, the former avirulent strain prevented the growth of the latter virulent pathogen. Experimental evidence indicated that the time elapsed between the first inoculation with the avirulent pathogen and the second inoculation with the virulent one was crucial to inhibit the growth of the latter. The growth of F7 on the plant without provoking damage and the fact that there was no in vitro antagonistic effect between the pathogens, suggests that the avirulent strain triggers a plant defensive response against M11. The defense response was further confirmed by the detection of an early oxidative burst occurring within 4 h after the first inoculation and by the observation of anatomical changes associated with defense mechanisms that lasted 50 days after the inoculation with F7. Results obtained support the hypothesis that the plant resistance against the virulent strain M11 is elicited by one or more diffusible(s) compound(s) produced by the avirulent strain F7.

Key words

anatomical characterization anthracnose Colletotrichum acutatum Colletotrichum fragariae cross-protection elicitor Fragaria × ananassa induced resistance oxidative burst 

Abbreviations

AOS

Active Oxygen Species

dai

day after inoculation

DSR

Disease Severity Rating

hai

hour after inoculation

RH

Relative Humidity

SEM

Surface Electron Microscopy

Copyright information

© Springer Science + Business Media B.V. 2006

Authors and Affiliations

  1. 1.Instituto Superior de Investigaciones Biológicas (INSIBIO; CONICET- UNT) and Instituto de Química Biológica “Dr. Bernabé Bloj”Universidad Nacional de TucumánSan Miguel de TucumánArgentina
  2. 2.Sección Biotecnología de la Estación Experimental Agroindustrial Obispo Colombres (EEAOC)-Unidad Asociada al INSIBIOTucumánArgentina

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