New Disease Reports (2006) 14, 13.

First report of Aspergillus flavus causing fruit rots of peaches in Greece

T. Michailides 1 and T. Thomidis 2*

*thomi-1@otenet.gr

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Accepted: 31 Aug 2006

In July 2005, rotted peaches (about 1% of the total) of the cultivars ‘Sun Crest’, ‘Andross’ and ‘Sun Cloud’ were observed in commercial orchards in Imathia County (northern Greece). Infected tissues were pale and water soaked, and the spores were green and powdery, easily liberated when matured (Fig. 1). Aspergillus flavus was isolated and identified based on morphological characteristics. Isolation of the pathogen was made on acidified-PDA (2.5 ml 85% lactic acid per L nutrient medium). The plates were incubated at 23ºC for 5 to 7 days. Koch’s postulates were completed in the laboratory by inoculating mature peach fruits (cv Andross). Peach fruit were surface sterilized by dipping in a 0.1% chlorine solution, allowed to dry in a laminar flow hood, wounded with a sharp glass rod of 2 mm in diameter, and a 40 µl drop of a 5 x 105 conidia per ml suspension of fungus was placed over each wound. There were 30 inoculated and 30 control fruits (similarly wounded and inoculated with a 40 µl drop of sterile-distilled water) in a randomized design and incubated at 24-26°C for 7 days. Koch’s postulates were satisfied after re-isolating the fungus from inoculated fruit that developed symptoms similar to those observed on fruit collected from orchards.

This is the first report of Aspergillus flavus causing a rot of peaches in Greece. Fruit rots caused by A. flavus have been reported in peach orchards in other countries around the world (Jamaluddin, 1980; Singh & Prashar, 1989). Measures should be taken to limit any possible spread of this pathogen in future, since toxigenic strains of Aspergillus produce aflatoxins that are known carcinogens and toxic to the liver (Marasas & Nelson, 1985; Molina & Giannuzzi, 2002).

Figure1+
Figure 1: Mature peach (cv Andross) infected by the fungus Aspergillus flavus
Figure 1: Mature peach (cv Andross) infected by the fungus Aspergillus flavus

References

  1. Jamaluddin A, 1980. Organic acid composition of peach fruits during infection by Aspergillus flavus. Indian Phytopathology 32, 490.
  2. Marasas WFO, Nelson PE, 1987. Mycotoxicology - Introduction to the Mycology, Plant Pathology, Chemistry, Toxicology, and Pathology of Naturally Occurring Mycotoxicoses in Animals and Man. Pennsylvania, USA: Pennsylvania State University Press.
  3. Molina M, Giannuzzi L, 2002. Modelling of aflatoxin production by Aspergillus parasiticus in a solid medium at different temperatures, pH and propionic acid concentrations. Food Research International 35, 585-594.
  4. Singh RS, Prashar M, 1989. Post-harvest spoilage of peach and plum fruits in north India due to Aspergillus. Journal of Research Punjab Agricultural University 26, 62-64

This report was formally published in Plant Pathology

©2006 The Authors