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A transformation method has been developed for the phytopathogenic fungus Botrytis cinerea. Protoplasts were transformed with pAN7-1 plasmid carrying the Escherichia coli hygromycin phosphotransferase gene (hph), conferring hygromycin B resistance, downstream from an Aspergillus nidulans promoter. Molecular analysis, showed that transformation resulted in an integration of the plasmid into different regions of the B. cinerea genome and occurred through non-homologous recombination. The frequency was 2-10 transformants per micrograms of DNA. Transformants expressed phosphotransferase activity confirming that the hph gene conferred the hygromycin-resistance phenotype. All transformants analysed so far proved to be stable after several subcultures without any selective pressure.

Isolates of Penicillium spp. were collected regularly from 2001 to 2003 from the surfaces of apple fruit pre-and postharvest, and from the atmosphere of orchards and storage rooms in France. Penicillium spp. were not detected from the atmosphere of conventional orchards, while their density did not exceed 50 spores m − 3 in the atmosphere of organically managed orchards. Penicillium spp. were seldom detected on apple surfaces in the orchard. The density of Penicillium on apples increased from 10 to 50 spores cm − 2 after 1 month in storage to 300 -400 spores cm − 2 after 6 months. The level of airborne Penicillium increased by up to 2 × 10 4 and 2·5 × 10 3 spores m − 3 within nondisinfected and previously disinfected warehouses, respectively. Penicillium expansum (30 -62%) and P. solitum (6 -45%) were the most prevalent species on apple or in storage rooms. Other species of Penicillium isolated included P. commune , P. verrucosum , P. chrysogenum , P. rugulosum and P. digitatum . Apple fruit were also surveyed for wounds and the number of open lenticels using the sulphur dioxide test. The incidence of wounding at harvest varied from 12 to 36%, depending on cultivar and locality. When apples were inoculated at harvest by either aqueous or aerial inoculum of P. expansum , the decay incidence was constantly higher than the incidence of wounding. The number of open lenticels per cm 2 of apple surface varied from 0·5 on cv. Boskoop to 4·4 on cv. Golden Delicious. An average of 13 and 2·1% of lenticels, respectively, were infected when they were inoculated by P. expansum and P. verrucosum . Cultivars of apple fruit that showed a greater number of open lenticels, combined with a large diameter varying from 100 to 200 µ m, were more susceptible to P. expansum .

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