Abstract: In this paper, the inhibitory effects of hot air treatment (38℃, 96 h) on the blue mold rot of
app les fruit (Malus domestica Borkh. ‘Red Fuji’) were investigated. The activities of related enzymes of dis
ease resistance were also determined. The decay incidence and lesion area was 78.33% and 20.83 cm² re
spectively on the app les only inoculated with Penicillium expansum spores after storage at 2℃ for 8 weeks.
Compared with the control apples, the decay incidence and lesion area was reduced by 16.67% and 22.8%
respectively on the heat-treated app les before inoculation. Further research found that, the phenylalanine am
monium lyase ( PAL) and peroxidase ( POD) activity, the content of lignin and total phenomena of treated ap
p leswere higher than controls at the later period of storage, which imp lied that heat treatment enhanced the in
duced disease resistance of the app les to P. expansum.

Key words: Apple, Hot air treatment, Blue mold, Induced disease resistance