Archivio Journal of Plant Pathology

Abstract:

‘Golden Delicious’, ‘Granny Smith’ and ‘Red Delicious’ apple fruits were wounded at their equators to give one puncture wound (3 mm diameter x 3 mm deep) and one shallow-slice wound (4.0 mm diameter x 0.4 mm deep) on opposite sides of a fruit. Freshly-made wounds (0 day old) or wounds that were 1 day or 3 days old prior to inoculation were inoculated with 50 or 500 conidia per wound of Botrytis cinerea or Penicillium expansum. After 7 days incubation at 22°C, 1 day or 3 day-old puncture wounds had less decay severity and incidence from either fungus than 0 day-old puncture wounds. Conversely, 0 day-old slice wounds were more resistant to fungal decay, whereas 3 day-old wounds were less resistant. This wound-type effect was found with both inoculum densities and for all cultivars. It occurred in ‘Golden Delicious’ fruits after incubation for 30 days at 3°C. This is the first report of wound type affecting the outcome of fungal infection in apple fruits. Understanding this effect may prove useful in devising a comprehensive theory of host resistance to fungal infection in apple fruit.